Oratex Fabric Covering Revisited

[Denali]

Is anyone considering using a product called "Oratex" to cover their KitFox wings and fuse?

Back in 2011 there was some discussion here about using a relatively new German covering product called Oratex. Here are the old threads:
http://www.teamkitfox.com/Forums/showthread.php?t=2128&highlight=oratex

Oratex has two websites, one for Germany and the other for their US Distributor who is in, why of all places, Anchorage, Alaska !! :) Yeah Alaska !!!

Germany:
http://www.oracover.de/

USA
http://www.betteraircraftfabric.com/oratex.html oratex6000 (http://www.betteraircraftfabric.com/oratex.html%20oratex6000)

This new Oratex material comes in two thicknesses (which they designate as 600 & 6000). It has gotten a lot of discussion on some of the other sites:

http://www.supercub.org/forum/showthrea ... ght=oratex (http://www.supercub.org/forum/showthread.php?42211-N3150P-Expermental-PA11&highlight=oratex)
http://www.supercub.org/forum/showthrea ... ght=oratex (http://www.supercub.org/forum/showthread.php?44392-Oratex-Fabric&highlight=oratex)
http://www.supercub.org/forum/showthrea ... ght=oratex (http://www.supercub.org/forum/showthread.php?44391-Oratex-UL-6000-Fabric-Covering&highlight=oratex)

Claimed advantages include lighter weight, ease of application, availability in many colors, etc.

Right now I'm looking at building a somewhat larger non LSA 4 place aircraft, but I have always had very very high regard for Kitfox. Actually if the right deal came along, I'd probably jump on a Kitfox as well. There is no FAA regulation...( yet)... which says one can only own one aircraft. :)

Any KF builders care to share their thoughts ?

Safe skies....

[Spook712]

Hi, I saw it being used in Germany, they did an AN-2 Biplane with the oratec 6000.
But I didn't use it myself so far

Greets
Tuna

[jrevens]

I got a sample kit at OSH last year, which I haven't used yet. There was also a guy covering his Kitfox with the stuff there. He was doing it right outside on the grounds in the ultralight area. I'm going to play with it a little and see if it's a viable alternative for me.

[rogerh12]

Here is what an air-frame mechanic, with decades and decades of experience told me: Don't put anything on your plane that has not already been on planes at least 20 years. That advise was free, but worth big bucks (hear about the water born covering system tried on Ag-cats? Lasted 2-years, then required 100% recover). Roger

[Flybyjim]

Do you have a site I can visit about the agcat covering, would like to investigate the issue.

[rogerh12]

Flybyjim:
The Ag-cat story didn't come from the internet (surprise! ), it came from an actual mechanic standing in front of me. To be exact, he was buying my cassutt kit ( Reno air racer) a couple years back. He did the work on the Ag-cat himself. He said, even sitting outside, exposed to chemicals, oil and pesticides on a regular bases, the old solvent based process (Stits ?) will produce a finish that will last a solid 20 years.
Roger

[Esser]

Here is what an air-frame mechanic, with decades and decades of experience told me: Don't put anything on your plane that has not already been on planes at least 20 years. r

While I know what the guy was getting at, I think this is one reason the aviation is held back. Attitudes like this are why we are just starting to get EFI 30 years later. There have been a lot of good start-ups that went bankrupt because everyone was waiting for the next guy.

[HighWing]

Here is what an air-frame mechanic, with decades and decades of experience told me: [I]Don't put anything on your plane that has not already been on planes at least 20 years. Roger

I think I have to go with Roger and his friend on this one.

I checked the Oratex site and the preliminaries pretty much turned me off.

I didn't count the number of times "toxic" was mentioned, but it was a bunch. For an amateur builder who will cover one or maybe three airplanes in his lifetime, in my opinion, "toxic" is not an issue. I remember many times in the past where Polyfiber and its MEK based adhesive was panned with words like "extremely hazardous" and "carcinogenic". Check the MSDS. It is pretty benign unless you cover in a closed room or decide to see what it tastes like.

Then they talk about the "ten or more coats is common and 20 is not unheard of" and the time to apply as a big negative. I might have had ten coats on my first airplane, but I had a very complex color scheme that accounted for the last four coats. If you want a color scheme or a fine finish using Oratex you will have to paint it as well, though if you are OK with a single color on each panel - no paint required.

Check out the photo galleries. the fabric seems sort of transparent. Then the Problems with other fabrics gallery. I have seen this type of problem, but it has usually been after using one system for cover and then using an incompatible top coat system. I saw this a lot at a Rans fly-in where they used auto paint over Polyfiber.

In twenty years, I might change my mind.

[jrevens]

I tend to be very cautious of the latest & greatest too. Being pretty old-fashioned, I really like "steam gauges" & the look of round dials, especially on something like a Kitfox. I'm gonna get a color tv someday also... when they perfect them. ;)

The Oratex is not translucent. It's opaque, very tough, & light. They make color-matching paint, trim material, etc. The glue seems to be similar to Stewart System's, which is really nice. It's a pretty slick idea, & ideally I'd like more "history" also before committing. Esser's got a good point, & technology's advance would be pretty slow if nobody jumped in on the ground floor.

[jamesmil]

saw this covering system on line and was intrigued by the simplicity, sure does cut out a lot of work and need to build a paint booth in the shop. also will save a lot of weight. also I under stand that rans will offer it in the rans 6es kit that uses per finished envelopes. all that being said I think I would give a good look if I were going to cover another airplane and was looking to save time and weight. just my 2 ct.

[Denali]

I think what will be interesting is to see if many of the manufacturers like Just, Rans, Kitfox, Backcountry Super cubs, etc begin to use it. The weight and application time savings are considerable.

This will be something to ask at Oshkosh 2014. :)

[dholly]

I was unable to get a firm price on materials to recover an Avid/Kitfox size from the manufacturer or US distributor at OSH last year, as they did not have an appropriate plane-specific materials list figured at that time. All I got was "subject to exchange rates" and "approximately 20% less materials cost than competitors".

The attached 2011 Poly Fiber materials and price list says an Avid/Kitfox covering kit cost $2,470 suggesting the Oratex covering cost should come in ~$1,976. Very curious just how accurate that figure might be.

Has anyone even got definitive info regarding a materials list and total cost for a Kitfox yet or, better yet, actually purchased the product?

Thanks.

[txskybolt]

Reading their website, believe they say the fabric is more expensive but in the long run, it will be less counting not having to buy equipment, chemicals, etc. The polyfiber quote is minus paint. The new covering is paint free (but can be painted). If I were covering a light, slow aircraft, I'd seriously consider using their product. You could dress it up with decals.

[Timberwolf]

Doing some reading the cost of materials to do a super cub is $6000 for everything but the wings-$9000 total including the wings. They claim the labor and painting costs offset that. Would probably worth it to not have to paint it then have chipping and cracking issues down the road. But they admit on their site no real long term testing has been done to see how it fares with the elements. They do mention having good luck with it on cubs in the extremes of Alaska.

[jiott]

I would have 3 concerns about the Oratex:

Does it have enough silver UV protection built into it? In my Polyfiber process 3 cross coats (6 total coats) of silver were used.
If you were using it unpainted, and had a color scheme where you need to change color along a structurally unsupported line, you would have to make an unsupported seam along that line. How durable is that seam?
All the finish tapes would only be held down by one application of glue. Again I think of all the layers of Polybrush holding my finish tapes in place.

[snowpaw]

Hi TeamKitfox members,
I just recently read an interesting article in the January 2014 issue of EAA Experimenter (see link) about a STOL-plane covered with Oratex that I thought I shoul share with you all.

http://experimenter.epubxp.com/i/247918

The builder/pilot wanted to reduce the weight and used Oratex and he was very positive about using it again.

In the article it is written that the plane unfortunately burnt down in a hanger fire, but there's no further comment about the effect from fire on the covering.


Maybe the builder/pilot would be willing to share some experience about covering, durability, the effect from fire on the covering, etc. if he's contacted?

If all charactertics descibed in the datasheets are valid, it would be very nice to use the Oratex covering. Imagine the weight reduction and not having to paint more than the aesthetics?

Later on I will try tro find out more about the German company who's producing the material.

[Spook712]

Check out these videos on Youtube, thay covered an AN-2 Russian biplane with ORATEX 6000, I've seen it and it look great.

Also check out the Kiebitz from MENS, it's covered with Oratex as well.

Greets from Germany
Tuna

http://www.youtube.com/watch?v=9ee1tWDdfbM

http://www.youtube.com/watch?v=7DlZGL28Y2s

[jrevens]

I made the statement that Oratex was not translucent... in looking at the sample I have, it appeared to be opaque. My apologies to Highwing - you were right Lowell. When you get the bright sun shining through it, the structure behind can be discerned. I would guess that the 600 material would be more translucent than the 6000 that I have. It sure is very tough stuff though - I covered a test structure with my sample, & after I extracted my foot from my mouth, I stomped on it (the sample), hit it & poked it. It can stretch a little with such abuse, but a heat gun shrinks it right up again. It is more puncture resistant than Poly-Fiber/Ceconite also, as well as lighter & scratch resistant. Easily field-repaired.
Has anyone on this forum used this material yet? It would be great to hear of experience. I've talked to a fella' named Roger Peterson, in Texas, who has covered a couple of Cubs with it. He loves it. My understanding is that there is one aircraft that has been covered with this material for 10 years at this point, and is looking good.

[jiott]

If it is even somewhat translucent I don't see how it could possibly be UV resistant. The Polyfiber manual has you putting on multiple coats of the silver UV Polyspray until you can't see any light with a 60 watt bulb on the other side of the fabric. Maybe I am missing something here-is there a way to filter out all UV rays with a translucent material?

[Danzer1]

The goal of UV protectant (in this case) is to protect the covering material, not whatever's on the other side. On a window you are protecting the stuff on the inside of the window (furnishings, carpet, etc.). The Polyfiber method is simply used for a layman (home builder) to discern if you have enough coverage for their method (and is likely overkill). I'm suspecting the Oratex pre-impregnated material is more efficient (being factory applied) and (I believe) it has been tested to ensure it's adequate for it's intended purpose.

Greg

[bushfly]

I was told by betteraircraftfabric.com that the Oratex 6000 is $76.85 per square yard and the Oratex 600 is $53.80 per square yard. It should be noted that that is square yard vice linear yard in case you want to compare with ceconite or Polly. I am just wondering if a Kitfox SS7 can be covered with 600 vice 6000. According to their website any LSA can be covered with 600.

[jrevens]

Hi bushfly,
The Oratex 600 is approved for aircraft with a MTOW of 1323# (600 Kg). The 6000 goes clear up to 13,228# (6000 Kg). The 600 can probably be compared to the light PolyFiber fabric. I think that a SS7 covered with 600 would be marginal. The airframe is designed for 1550# gross, & you would be limiting yourself if you ever wanted to increase your weight to that limit (taking it out of the LSA category). That would be my concern. The 6000 is tougher, while still being considerably lighter than a conventionally finished/painted covering.

[Little_Cub]

Hi TeamKitfox members,
I just recently read an interesting article in the January 2014 issue of EAA Experimenter (see link) about a STOL-plane covered with Oratex that I thought I shoul share with you all.

http://experimenter.epubxp.com/i/247918

The builder/pilot wanted to reduce the weight and used Oratex and he was very positive about using it again.



Hi All.. Lil' Cub burned December 17th 2013 and we started the re-build mid January 2014. After three months of pretty intense work (for my wife and I), retired grandparents, we have a new Lil' Cub and she flies better than ever.

One interesting thing we can report is the fabric was almost welded to the fuselage (after the fire).. it took vice grips and wire brushes to get the old stuff off.

We had flown a winter in Arizona (stored outside) and the summer in Alaska.. about 470 hours flying time before the burn and everything was holding together well.
The first time we rushed the process and completed the (fabric) on the entire Cub in 4 LONG days! This time more time was spent but it still is much faster/cleaner than anything out there. My wife has never been an aircraft buff but she likes to be involved in my projects.. she would always run the other way when it came time for fabric. This stuff is clean and with no stink she took over on the second build.. the fabric was hers all the way!

It's easy to apply however it stands much more heat than other processes, for me it was difficult to believe it and apply the required heat. It lays down smooth and unlike the other glues.. when a seam is re-heated the glue turns liquid again between the layers and gets even smoother the second pass!

Before I rattle on too much.. we don't sell the stuff and are not associated with ABetterFabric (Lars) but when I like something.. I like to rave a bit.

Oratex allows us to still feel productive without the health dangers.. growing up in a body shop we ingested enough bad stuff.

In closing we figured we saved someplace between 20 and 25 pounds on our Experimental Cub build.. if you can find something to replace with Carbon or Titanium it generally costs between $500 and $1000 per loss of pounds. Its like getting a $10K-$20K check when doing the fabric!! We all want performance and know weight to HP is where it's at.

If you want more 'biased' independent report give a call.
Thankz for listening,

frank (Lil'Cub)
907-841-0298

[HighWing]

For what it's worth.

I talked to a buddy last week and he is in the process of covering the wings of a friend's Rans S-7 with Oratex. He has built and covered Three or four Kitfoxes, two Rans S-7s and now this Rans. He recently worked in a restoration shop that does Cubs - he was the fabric guy.

He is experienced with Polyfiber and Stewart Systems.

His take on Oratex:

Four days - no way! That is the first thing he mentioned. They have more than four days on just the S-7 wings.
Translucent - You can see the gray of the underlying structure through it.
Difficult to work with - have to glue fabric panels together.
Difficult to smooth - Permanent wrinkles.
Does he like the result - No. Does his friend the S-7 owner like the result - No.
Is it expensive - Yes. He mentioned don't forget the cost of the adhesive

Consider that this is one level second hand, but if anyone has specific questions, drop a PM and I will pass the questions on or hopefully get his permission to release his contact info.

[Little_Cub]

For what it's worth.

I talked to a buddy last week and he is in the process of covering the wings of a friend's Rans S-7 with Oratex.

Well.. where to start. First I apologize for going against a long term user of the site.. I am a lurker and have no right and only appeared because my wife and I.. like the stuff.

1- Start day we completed the first wing and started the second.
http://www.alarmspro.com/Fabric/4.png

Completion AFTER the DAR had signed off the build.
http://www.alarmspro.com/Fabric/5.png

PLEASE NOTE THESE PICTURES ARE FROM A WEB CAM WITH DATE/TIME.

2- Translucent - He got me there.. it looks light. This is a photo with low angle Alaska sun shining directly on the side.. note the tail.
http://www.alarmspro.com/Fabric/2.JPG

3- Difficult to work with.. well it takes about 30 minutes to place glue on one wing.. BOTH the ribs and fabric. If you do it light the dry time is about 3 hours. Now your ready to tack in place with an iron and go to town.

4- Difficult to smooth- Hmm I'll rely on pictures of my wife doing the tail.. takes care but sure nice once complete. (Not a ripple)
http://www.alarmspro.com/Fabric/6.JPG

The thing is.. if you don't get it smooth at first you can do it again and it only gets better.

Wing:
http://www.alarmspro.com/Fabric/1.JPG
http://www.alarmspro.com/Fabric/7.JPG

5- Does he like the result (No) - My wife has only helped on one other fabric job but the result was better than most.

6- Expensive- I guess so.. I'll sure do it again based on the weight $avings.
Just having my wife out there made the cost seem slight.

I can easily see why an ol' timer that already has a system worked out with paint booth, guns, compressor and fresh air supply might not want to venture into Oratex however I believe it is good for the rest. When I painted (two part) every day I thought I was superman.. no longer.

Sorry for infesting the list with chatter, again I just like the stuff. If we can help with any specific questions please call or PM.

Over and Out
frank
907-841-0298

[jrevens]

I talked on the phone with a fella' named Roger Peterson in Sweeney, Texas who's covered several Super Cubs with Oratex. He loves it, & said he wouldn't ever use anything else again. He has videos on the net detailing a lot of his experience with it.

I also talked to Randy at RANS... they are doing some covering with it now. They are differing from the recommended installation process, in that they are sewing up "envelopes" in order to speed up the production process and get a good fit around certain kinds of curves. I don't know how successfully that is working for them, but getting a good, tight, definitely wrinkle-free job doesn't seem to be particularly difficult at all. It requires installing the fabric as tight as possible to begin with, as the shrink percentage is a little less than PolyFiber for instance. There is much less worry about deforming structure, but the tautness seems great. The necessary skills/techniques are a little different than PolyFiber. Paint can cover a "multitude of sins", & if you're looking for an Oshkosh award-winning look, you probably want to paint. If you're looking for the lightest, strongest, fastest installation and completely safe & non-toxic it's worth a look.

I know a guy in South Dakota covering a Cub. They've covered aircraft as big as one of the Antonov AN-2 biplanes with it.

Just Aircraft has also been using some of it, I've been told.

I don't know if Frank (Little Cub) is using the 600 or 6000 material, but I would imagine the slight translucence is less with the thicker 6000. I don't mind that at all on the few examples I've seen.

FWIW.

[colospace]

Frank,
Never mind the "lurker" deal, I appreciate your input as I too am considering Oratex. I was put-off by the Kitfox that was being covered at Oshkosh last year and the price, but the weight and time savings are certainly appealing. Appears your wife did a nice looking job. I'm looking forward to seeing how it works out for John.

[jrevens]

OK, so I confess... I received my shipment of Oratex stuff yesterday. I'm sure there are those on this list who will shake their heads, but I think I'm going to do fine with it. A lot of soul-searching & research the last couple of years, & I finally jumped in. After seeing it at OSH a couple of times, & talking to several users, then playing with the sample kit I got, I made up my mind. Invested in a good digital heat gun. You still need a good iron also (digital is good). A heat gun is highly discouraged with PolyFiber, but works beautifully with Oratex. Oratex doesn't start to loosen, unlike PolyFiber, when you heat it above a certain point. It shrinks & is fine right up to the point where it is melted & destroyed - I believe about 485 deg. F. The "hot melt" glue is neat. Brush it on, let it dry, then it is melted with heat (100 deg. C, 212 deg. F) & pressure from the iron (or heat gun & felt pad) to stick things together, which also starts a chemical reaction. This causes the bond to strengthen, & the glue will not melt again until a much higher temperature. I'll try to post some pictures as the project progresses.

[bushfly]

How much did it cost you in materials for the kitfox and how many yards did you get?

[cap01]

john, what iron did you get?

[jrevens]

bush fly,
I carefully calculated the necessary material by laying it all out on graph paper. One thing that made it doable with less yardage was that Oratex was able to provide the material in a width of 76.5", so I can get the wing panels & then the tail feathers (except the vertical fin) out of the remaining strip in that area. Everything else comes out of the remaining length. The SS tail surfaces are larger than, for instance, on a IV. So I ordered 25m (82') of this extra wide batch. It leaves me enough extra for perhaps a tail surface screwup, & plenty for doilies, etc. Not a lot of margin for error. I'm going to take my time... definitely won't be a 4 day job for me. Asking how much it cost is like asking a guy how much he makes. I'm embarrassed to say, especially since I've got all this nice PolyFiber material & tape from the kit (I did sell the polybrush & glue). What's your name anyway? You look like my cousin from Wisconsin. ;)

[jrevens]

cap01,
I made a digital iron, but gave it to a friend. So I bought a Toko T14 that I found on the internet for a good price because I didn't want to go through the hassle of building another one at this stage.

[jsteere]

I talked on the phone with a fella' named Roger Peterson in Sweeney, Texas who's covered several Super Cubs with Oratex. He loves it...

OH OH! Someone must have really screwed up! Apparently the judges at Oshkosh didn't get the memo saying "Paint can cover a "multitude of sins", & if you're looking for an Oshkosh award-winning look, you probably want to paint." The very first aircraft to attend Oshkosh (2012,) covered with Oratex UL 600, won the Ultralight Reserve Grand Champion award. http://www.betteraircraftfabric.com/photo-galleries/bodacious/bodacious04.jpg
No paint was required. The fabric is great, and I would absolutely use it again. Let me know if you have any questions. John
Additional info here - http://cluttonfred.info/post/28209541398/clutton-fred-oshkosh-update-2-john-steeres#.U30RyeNOWbE Interview video here - http://www.youtube.com/watch?v=cw-WRTf9LqY

[Av8r3400]

I know that plane very well from Airventure '12.

The covering was definitely a factor in why it got the Lindy. Innovation in products and usage is something closely looked at. It looked very nice.

If I wasn't already committed to poly fiber on my project, I might give it a look...

[cap01]

for the last project I got the toko t8 . I figured for 60 dollars I'd try it out . the thing worked fantastic , wish I would have popped for the t14

[jrevens]

Hi John,

I remember your plane at OSH. It was beautiful! I tried to locate & check out every Oratex covered ship that I could at Oshkosh the last couple of years. I certainly didn't mean to lump every user of a certain product in one basket. You're absolutely right - I misspoke about an "Oshkosh award winning look" and I do apologize! I was actually paraphrasing an opinion that was expressed to me by a major kit-built manufacturer. I have seen some terrible looking Oratex jobs, as well as Ceconite or PolyFiber ones, & frankly paint CAN help to hide a lot from the casual observer. But there is no reason that an aircraft covered with Oratex can't potentially be an award winner anyplace. I like what I see with it, I like it's properties & strength, and that is why I decided to make the substantial financial investment to cover my project with it, when I already had most everything to do a PolyFiber job. I hope I can do half as good as you did!


OH OH! Someone must have really screwed up! Apparently the judges at Oshkosh didn't get the memo saying "Paint can cover a "multitude of sins", & if you're looking for an Oshkosh award-winning look, you probably want to paint." The very first aircraft to attend Oshkosh (2012,) covered with Oratex UL 600, won the Ultralight Reserve Grand Champion award.
No paint was required. The fabric is great, and I would absolutely use it again. Let me know if you have any questions. John
Additional info here - http://cluttonfred.info/post/28209541398/clutton-fred-oshkosh-update-2-john-steeres#.U30RyeNOWbE Interview video here - http://www.youtube.com/watch?v=cw-WRTf9LqY

[bushfly]

John it's Bushfly or Ed Hensel in WI. I will be covering my SS in two months. I considered Oratex but it is hard to justify dropping over $6,000 when I can use Stewart System and fabric that came with the kit for far less.

[jrevens]

Hey Ed,

Thanks! Man, you look like my cousin.

I understand completely. There was a lot of soul-searching before I dove in.

Good luck with your covering!

[Esser]

John it's Bushfly or Ed Hensel in WI...

Is that the going rate for a kitfox sized plane?

[jrevens]

By the time you figure all the finish tapes, glue, etc.... yep.

[Esser]

So roughly double. Well that's probably a good price for the weight saving but I have my polyfibre stuff. Maybe John should look into it as an option for future kits. Carbon fibre and oratex, you might squeak one under 700lbs if you were stingy on weight everywhere else

[HighWing]

I am curious beyond curious. I am aware that any covering system is a significant part of the empty weight of any airplane. I recall during the Arab Oil Embargo, US airlines removing paint from the airplanes as a fuel saving mearure. And I am aware that LIght has significant benefit beyone GPH.

But, Does anyone have any idea roughly or exactly, how much weight saving is to be had using the Oratex system?

[Esser]

In closing we figured we saved someplace between 20 and 25 pounds on our Experimental Cub build.. if you can find something to replace with Carbon or Titanium it generally costs between $500 and $1000 per loss of pounds. Its like getting a $10K-$20K check when doing the fabric!! We all want performance and know weight to HP is where it's at.

If you want more 'biased' independent report give a call.
Thankz for listening,

frank (Lil'Cub)
907-841-0298

This is what Frank said abotu his lil' cub which is probably a similar size

[jrevens]

I am curious beyond curious. I am aware that any covering system is a significant part of the empty weight of any airplane...

Just roughly, but I have heard from several users that a cub size airplane can save around 25 to 30 lbs. There are other factors besides weight that also appeal to me. The strength/toughness is one. It's amazing to see the demonstration where a ball-peen hammer is used to beat on a panel (hard). A small amount of stretching/dimpling is the result, and application of heat with a heat gun takes it right out. Doing the job in the comfort of my shop/basement with no toxic fume issues is also nice.

[Sabre]

The new edition of Kitplanes has what looks to be a pretty informative article on covering with Oratex.

[Planesmaker]

Weight saving? I recently removed all fabric from a skyfox( an Australian production based on the kitfox 3) in preparation for recover, the weight of which was less than 10kg(22lbs) for the entire aircraft. Unsure weather it was 1.7 oz or 2.7 oz but really saving 20 to 30 lbs? I doubt it. Tom

[LSaupe]

Any more feedback on this covering system? Interested to hear from anyone who has experience with the product.

Larry S.

[HighWing]

I saw this covering on an airplane this past weekend. Most of the airplane was Polyfiber. The cover material was white with no design and unless looked at closely it looked just the same as the bulk of the covering. The sun was bright and it was difficult looking at it in the direct sunlight. It was slightly translucent as you could see internal structure as shadows in the overall material. I also noticed what looked like pencil lines around most of the inspection rings, but on closer examination, it appeared to be dust collecting on the edge of the pinked fabric rings. I also noticed that some of the finishing tapes had edges that could be lifted up with a fingernail - not fully glued down. It is a different material and apparently a whole different set of procedures need to be used to make sure all is as it should be.

Example: with the wet glue on the finish tapes, you can see the adhesive through the finish tape as it fills the weave. This gives some hint as to how the tapes are bonded. Then you can attack with the finishing iron those pinked triangles that appear whiter than the others. With the Oratex, every inch has to be heated and inspected to ensure bonding - less saturated with adhesive. You are not using the iron to smooth the edge, but rather applying heat that activates the adhesive. Then since there is no finish coating to radius the edges of the various layers, I suspect the dust lines might remain problematic on the lighter colors though just guessing there.

Please consider that these observation are from a person who has seen one example only and I am not experienced or fully aware of the procedures used in the covering process.

[jrevens]

I've just barely started using the Oratex. I think it's looking good so far, to me. Lowell's right... it is different and does require different techniques than PolyFiber. I'm almost done with the rudder, which I decided to do first as it involves most of the various "tricks" that will be needed. I have heard that some folks who have had problems are those who have a lot of PolyFiber/ceconite experience. You have to follow the directions closely, just like most things.

If edges are able to be lifted with a fingernail then someone probably didn't take enough care in the process. It is not hard to ensure that finish tapes are properly heated, & and if so done, the fabric will tear before the glue bond fails. It seems that most people are using the pinked finishing tapes, and I am using straight edge - they come either way, same price. I believe those using pinked edges are doing it mostly for the traditional look. Honestly, you can't tell the difference from 10 feet away, & I've decided that I like the look close up also. The reason I chose straight is because there is less exposed edge, & I think that is better from an engineering standpoint with this system. There is no need to pink, as the fabric doesn't unravel or fray like unfinished ceconite. Since there is no overcoat of paint, all those little pinked points can be potentially problematic in my opinion. So far I like it... we'll see as time goes on. I'll try to post a few pictures sometime soon.

BTW, the Australian Skyfox was almost surely the lightweight fabric. I've weighed all the over-sized panels that I cut out for the entire airplane, & the weight was less than 14 lbs.(much of that will be cut away). There is a little more fabric on a Series 7 of course also. This is the 6000 material, which is stronger than 2.7 ounce PolyFiber cloth. Add finish tape & glue, & I estimate another +/- 5 lbs. Depending on how much paint you put on a conventional job, I don't think that 20-25# weight savings is too far off.

I'm not trying to sell this stuff to anyone. I'll just try to relay my experiences as I go along.

[jrevens]

One other minor point related to HighWing's previous post - when using heat to activate the adhesive, you actually do "smooth" the edges. The more you iron & apply pressure, the smoother it gets. Any little "blobs" underneath are softened & smoothed. Same thing with minor wrinkles, etc. after being heated to activate it, the glue cross-links & develops greater strength over a period of days, & then requires a much higher temperature to melt. It is a stronger bond than the PolyFiber glue - see the latest Kitplanes article.
Also, some of the dust lines seen by Lowell may have been due to adhesive applied to the fabric too close to the edge of the tape. The glue is clear, but looks a little different/darker when heated. The tapes come with glue pre-applied, & you apply a thin layer to the underlying fabric, keeping it a short distance from the edges. The glue is not at all visible at the edges if done properly. The glue on the tapes alone is adequate according to what I've been told, but applying it to the fabric adds additional "insurance".

[jrevens]

As promised, here are some pictures of my initial foray into Oratex land. I haven't had much time to work on it, but I started with the rudder (which is now complete & ready for flight), and am now working on the elevator. I'm getting more comfortable with the process, & I like the look.

[LSaupe]

Great pics. I am amazed at how well the painted parts match the material.

Please keep us posted on how the wings progress. Will you be doing any rib stitching?

[rocketman2tm]

I am looking at using this fabric as well. I am very curious as to whether you reinforced the trailing edge of the wing to ensure it does not warp. The instructions for Oratex say that it should not ruin structures like that but I wonder if I should just reinforce it anyway. I'm not to the point of loosing sleep over it, but give it another couple of months and I might be.

[jrevens]

I did reinforce the trailing edge with 3/8" Al tube. Oratex does shrink to the proper tautness, but it doesn't continue to tighten to the point of structural deformation, unless the structure is very thin or weak. You can apply heat right up to just below 482 deg. F., at which point it melts. I just felt good about strengthening the trailing edge.

Here are a few more picture of working on the rudder...

[jrevens]

Great pics. I am amazed at how well the painted parts match the material.

Please keep us posted on how the wings progress. Will you be doing any rib stitching?

I will lace the wing ribs.

[Danzer1]

John,

That looks very good! It appears in your photos that the Oratex fabric and tape has a much smoother weave than the others. Is that just my perception of the photos or is it smoother in your opinion also?

Keep up the fine work - you are inspiring!

Greg

[jrevens]

John,

... It appears in your photos that the Oratex fabric and tape has a much smoother weave than the others. Is that just my perception of the photos or is it smoother in your opinion also?...

Greg

Hi Greg,

I'm not real sure about the weave comparison. Oratex definitely has a "texture" that you don't have with a conventionally covered/painted surface. It is a very fine weave, & visible on the finished surface. The 600 (the "light" material) is different than the 6000. It has an even finer weave. I chose to use 600 finish tapes (they are available made of 6000 material also). The 600 stretches & conforms around curves a little easier than the heavier stuff. You can also get pinked or straight edge. Because of the different texture, the lighter tapes have a little different look even though they are the same color - perhaps because of reflectivity. I'm sure you can see it in the pictures. I don't mind that.

Thank you for the kind words.

[Dave S]

Hi John,

Your covering work really looks nice.....What type of paint do you use with this system?

Dave S

[jrevens]

Hi Dave,

They say that just about any type paint works well & adheres well to Oratex fabric. Water-based, MEK-based, urethane, epoxy, regular enamel, etc. No roughing-up of the cloth is necessary or recommended. Just clean thoroughly to eliminate any contaminants, skin oil, etc. I used some PPG acrylic urethane that I had, added a little flattening agent to take away some of the gloss, & used that with a small brush to touch-up/seal some small areas transitioning between fabric & steel (e.g. - at control horns on the rudder). Oratex sells their own non-toxic paint (probably similar to Stewart System's paint, I would guess), but it is very expensive to ship from Germany. You can certainly paint the fabric, but that would seem a waste of both money & weight to me. You can use colored fabric, plastic decal trim material (Oratex sells a large variety), or you can paint trim stripes.

[Paul Z]

After looking at the Web Site I can see why you went with it. Once it's covered your done, unless you want some graphics.

[jtpitkin06]

I’m pleased that John Evens is sharing his experience. We need first hand input.


I suppose everyone has an opinion on this product, as do I. What follows is my personal observation and it does not reflect the professional position of any manufacturer, mechanic or distributor of Oratex products. My personal experience with Oratex is a close inspection of an aircraft covered with the product. and spending a week at Oshkosh manning the booth with the factory workers that actually installed Oratex fabric on one of the display aircraft..I do not use their name here because I do not speak for the factory.


First the appearance. The display aircraft is covered with Oratex white. The finish is flat, not glossy or semi-gloss. It also has a bit of reflective sheen with certain sun angles. This is not a product that gives a model airplane Topflite Monocote type finish. The material is a bit translucent and resembles a nylon petticoat with a primer coat. The fabric weave is very visible… not partially visible as you might see in more traditional fabric coverings. If this is the type of finish you are looking for, then you will probably love it. I am concerned how the airplane might look after exposure to some Georgia red clay dust. I noticed after a week parked at Oshkosh that it was looking pretty dirty compared to conventional covered aircraft parked next to it. We found it very hard to wipe the morning dew off without smearing the dust and dirt into the weave. We had to use a water bucket brigade to clean it where the other aircraft we simply squeegee and wipe them down.


Next is the weight savings. I had extensive conversations with the factory workers that installed the covering.. This company builds lots of LSA’s so they know what the empty weight should be when the aircraft is covered. They stated the weight saving was between 4 and 6 pounds on a Cub size aircraft. If you are a weight fanatic then this product can save a few pounds over the usual fabric and finish with Polytone or Ranthane. A few pounds, yes. Thirty pounds? No way!


Application. Here is where you get different stories. Oratex says you can do it yourself. The LSA factory people said it took three workers… two stretching clamping and holding while the third was tacking and ironing. The product is not nearly as forgiving when doing compound curves and corners. Because the product is more expensive and the labor is higher, this LSA factory will install Oratext for you; but, it will cost you twice as much. The Oratex cost is compared to conventional covering doing all the steps of Polybrush, Polyspray and Polytone. (It’s just not that difficult to spray an airplane at a factory with a paint booth)



Fumes. No, it doesn’t smell. You can do it in an apartment and the neighbors will never complain.


Longevity. This is one area where I don’t have reliable data. Yes I heard they have been using it in Europe for years. That’s nice. They say the UV protection is in the treated fabric. That’s nice, too. Let’s see how it holds up after a few years of Phoenix sun.


If you are considering this product, I recommend you see an entire aircraft covered in the product prior to making a purchase of materials.. Also attend a session where an aircraft is actually being covered to see any installation problems you might encounter.


I tried to be fair in my evaluation of the product but my bias clearly shows. It is not my choice primarily because of the appearance. The cost for weight savings is not worth it for 4 to 6 pounds. No paint booth or spraying outside is a plus.


What I find is the opinion of the product varies widely. After a week on display I heard lots of comments. Some people love it, and others hate it.
I guess that’s why the make Fords and Chevys. Everyone likes something different.

John P

[HighWing]

They say that just about any type paint works well & adheres well to Oratex fabric. Water-based, MEK-based, urethane, epoxy, regular enamel, etc.

Be real careful with this. Several years ago, I attended a fly-in in Utah hosted by a Rans Build Center. They routinely finished with auto urethanes. I noticed cracks in the paint of some of the airplanes and a couple of the airplanes had spots where patches of the paint had lifted off and these were not old airplanes. Airplane fabrics require a paint that will flex a significant amount. I suspect the build center knew this and the airplane's paint had a flex additive but these additives are typically designed in auto paints to withstand the flex of the plastic bumpers - a little bit different than what you might find with a fabric covered airplane in the prop wash area for example.

[jrevens]

Be real careful with this. Several years ago, I attended a fly-in in Utah hosted by a Rans Build Center. They routinely finished with auto urethanes...

Absolutely right... good point, Lowell. Oratex actually sells 2 different basic paints - one that is flexible for fabric, & another for fiberglass, metal, etc. I was just trying to respond to a question & make the point that no special prep, other than making sure the surface is clean & oil free, is necessary for paint adhesion regardless of the type of paint.

[jrevens]

John Pitkin wrote:
"...I do not use their name here because I do not speak for the factory."

I wish you would share the name of the company, John... why not? As you said, you're not speaking for them. I talked to a worker at RANS who said he didn't like it, but this was when they were doing their very first Oratex job, and for whatever it's worth, they also do it quite differently in that they sew envelopes. This guy told me they didn't even use finish tapes, but I have no idea if he really knew what he was talking about or not.

..."I noticed after a week parked at Oshkosh that it was looking pretty dirty compared to conventional covered aircraft parked next to it. We found it very hard to wipe the morning dew off without smearing the dust and dirt into the weave. We had to use a water bucket brigade to clean it where the other aircraft we simply squeegee and wipe them down."

Yes, it has a "texture". As I said before, I'm pleased with the look of what I've done so far, but I've seen several Oratex cover jobs that were poorly done, in my opinion. The finished covering can be waxed. Oratex sells a wax also, but any good automotive wax or polish can be used as far as I know. That might minimize the issue you noted, I don't know. I'm planning to wax mine.

..."Next is the weight savings. I had extensive conversations with the factory workers that installed the covering.. This company builds lots of LSA’s so they know what the empty weight should be when the aircraft is covered. They stated the weight saving was between 4 and 6 pounds on a Cub size aircraft. If you are a weight fanatic then this product can save a few pounds over the usual fabric and finish with Polytone or Ranthane. A few pounds, yes. Thirty pounds? No way!"

Maybe we'll really get to the truth of this someday, but I believe that 20 to 25 lbs. is not beyond the realm of possibility. I think the fabric is similar in weight to the bare Polyfiber fabric (I'm going to try to weigh samples of each tomorrow, & I'll report back). If that is the case, then 30 lbs. can easily be added to an airplane of that size with paint. I measured a weight gain of approximately 30 lbs. when I painted my T-18, and it is a smaller airframe with a wingspan of 21 ft. That was 1 coat of primer & 2 relatively light coats of PPG Durathane (no clearcoat).

..."Application. Here is where you get different stories. Oratex says you can do it yourself. The LSA factory people said it took three workers… two stretching clamping and holding while the third was tacking and ironing. The product is not nearly as forgiving when doing compound curves and corners."

I've done it all myself so far... when I get to the fuselage it may be a different story - we'll see. Like many things, it is sometimes helpful to have a few extra hands. It is more difficult for me to do curves, than if I was using bias tape for example. It has gotten easier with experience.

..."Fumes. No, it doesn’t smell. You can do it in an apartment and the neighbors will never complain."

You also won't hurt yourself. One of the biggest reasons for some people to use it... it is completely non-toxic & environmentally safe.


..."Longevity. This is one area where I don’t have reliable data. Yes I heard they have been using it in Europe for years. That’s nice. They say the UV protection is in the treated fabric. That’s nice, too. Let’s see how it holds up after a few years of Phoenix sun."

True. 10 years in Europe. Any non-hangared fabric airplane is going to take a beating in Phoenix, or anywhere else for that matter. It's a question mark in my mind.


..."If you are considering this product, I recommend you see an entire aircraft covered in the product prior to making a purchase of materials.. Also attend a session where an aircraft is actually being covered to see any installation problems you might encounter."

Good advice. I agree 100%.

..."What I find is the opinion of the product varies widely. After a week on display I heard lots of comments. Some people love it, and others hate it."

Same thing, for instance, with the Stewart System.

[jrevens]

OK, I cut 2 one square foot (1'x1') samples of medium weight Polyfiber fabric & Oratex 6000. The results:

Polyfiber - 0.35 oz./sq.ft.

Oratex 6000 - 0.50 oz./sq.ft.

I have calculated that it takes approximately 45 sq. yards of material to cover a Series 7 SS Kitfox (I have cut all of the pieces - oversize - to do that, out of 50 sq. yds., with some left over). That gives us a projected fabric weight of approximately:

8.86 lbs. for Polyfiber &

12.66 lbs. for Oratex

So the finished difference is going to be close to whatever the Polyfiber paint job weighs minus a little under 4 lbs.

I think that 20 to 25# is a perfectly reasonable estimate... it could be more, it could be less.

A couple of other thoughts - the "textured" surface has been discussed as possibly being an aerodynamic plus (think golf balls, turbulator tape, etc.). That's probably a stretch, but who knows. Something else not mentioned by John P. is that the Oratex is considerably stronger. Other than the "classic look", it's got a few real pluses going for it.

Finally, I sure don't want to be responsible for anyone else using Oratex based on my experiences & reports alone. I do like it so far, but there are some question marks, and I realize that I'm being a little bit of a Guinea pig. You probably know how that feels with your choice of engines for your 'fox, John P. :)

[HighWing]

OK, I cut 2 one square foot (1'x1') samples of medium weight Polyfiber fabric & Oratex 6000. The results:

Polyfiber - 0.35 oz./sq.ft.

Oratex 6000 - 0.50 oz./sq.ft.



I'm going to chime in here largely because the covering weight issue has been going on for forever. In fact, I have been a skeptic forever.

First, the Polyfiber medium weight fabric is listed at 2.79 Oz. per Square Yard. The .35 oz. per sq. ft. would give a square yard figure of 3.15 oz per sq. yd. I can't explain the discrepancy. If it is scale error it would also affect the Oratex weight mentioned above. I weighed a sample of my own cut to exactly 1 sq. ft. and it weighed 2.70 oz. Be that as it may, I have always been a skeptic on the actual weights claimed for covering and painting. For some reason, I don't think that people who claim high covering weights using 50 lbs. of covering chemicals consider that the vast majority of that evaporates leaving a fraction of what is actually applied adding to the empty weight.

By coincidence, I am covering an elevator for an Avid. We redid the trailing edge to give more cord and added a trim tab modification. I am using Polyfiber. Using John's example, I have cut a very precisely measured one foot square piece of medium weight Polyfiber cloth. What I will be particularly interested in is the actual weight of the residual chemicals as I take it through the finish process with all the coatings up to final coats. I may even go there if time permits. I have finished the elevator to the first spray coat of Polyspray. I have done the same to my square foot sample.

I have attached a PDF of the spreadsheet I am using to save the numbers. As mentioned, I have a column that reflects the net addition of the chemicals to the basic cloth. I don't know if it is valid, but I presumed the fabric adhesives would be pretty much a wash on each technique. Another thing I did for completeness is add an estimated amount of 2" finish tape. I did this because the finish tape will absorb a certain amount of the Polybrush and will add its weight to the total as well - along with the weight of the tape. My estimate was one foot of 2" finish tape per square foot. I also used the .300 oz. per sq. ft. of my sample which reflects more accurately the fluid totals per square foot.

The finish coats supplied by Polyfiber are much thinner than the typical automotive urethane coatings so my estimate is that they will be quite close to the weight of the spray coat already applied. If the aluminum coating is twice the weight of the spray coat and the final finishes are three times the spray coat, it would only add 8.7 lbs to the total covering weight and this includes finish tapes. - time will tell.

[jrevens]

I'm really glad we're having this discussion also. It's good to get some "real world" experience and data.
If you meant 0.27 oz. for the sq. foot of fabric, Lowell, that would give you 2.43 oz./sq. yd. - considerably less than the published Polyfiber data. I used a calibrated electronic scale, but I can't personally verify it's accuracy without test weights. I wonder about the accuracy of your scale too. However, like you said, any inaccuracy would probably occur with both samples. I look forward to your experiment with finishing the sample, as I would like to know the true weight of the paint also. That's the most important piece of data.

Of course I have thought of the fact that the volatile components of paint evaporate, and also that there is a lot of difference in "cured" vs "wet" paint weight depending on the amount & type of "solids", the curing method, etc. The wet vs dry weight difference is going to be greater with Poly-Tone than with a urethane or epoxy finish. This makes the difference between the weight of a gallon of liquid paint versus the cured or dried result of that gallon much greater with the Poly-Tone for instance. There will be more evaporation of components

On my T-18, I weighed everything I could, before & after painting, to come up with the 30# figure. I weighed & painted the rudder, vertical fin. stabilator, ailerons, flaps, wing panels, wing tips, wheel pants, gear leg fairings, etc., etc. all separately. I then estimated the fuselage based on that experience. Believe me, it was very accurate.

Finally, if you are painting your sample with Poly-Tone, I believe that the finished weight might be considerably heavier with Aero-Thane... just a guess.

[HighWing]

Thanks John for calling attention to the typo. It should have read sq. yard as the sq. ft. weight was .300 oz. Just too many numbers for this old guy.

(Edit) I do have some calibrated weights and find that my scale weighs 1% high. Multiplying all weights by .99 gives a corrected weight - not enough to worry about so I am going to continue to use scale weights.

I would also welcome hearing abouit any errors anyone might find on the spreadsheet.

I plan on painting with aerothane. I'll have to think about the possible differences between the weights of cured and evaporative drying. It takes about a week before you can wipe the aerothane with solvents before it is fully cured, so it would be lightened considerably with evaporation before final cure. Aerothane is thinned 3:1

[jrevens]

Another bit of interesting info from Poly-Fiber's website, "Frequently asked questions" -

"When Cubs rolled off the line, they had 75 pounds of Grade A cotton and dope on them.

A Ceconite and dope finish on that same Cub will probably weigh about 50 to 60 pounds.

A Cub done in Poly-Fiber has 40 to 45 pounds of finish weight.

A Cub done in urethane can get pretty heavy if you lay on the thick coats. Urethane is not known for its light weight.

Ultralights can be done in as little as 12 to 15 pounds."


I'm believe that there must be a LOT of possible variance in weight of paint jobs due to application techniques & "desired look", not to mention type of paint. Those things are taken out of the equation with Oratex. I also wonder if there is some possibility that the weight of Polyfiber fabric varies from batch to batch. It seems unlikely, but that might explain the difference between Lowell's & my 1 sq. ft. samples. I did obtain some test weights last night & verified the accuracy of my scale.

[HighWing]

Regarding weight comparisons, the elevator I have been working on, is finished to the two cross coats of white. I added these weights to the spreadsheet to give final results of the chemical weights up to the white Aerorothane only.

I would like to make several comments as to methodology.

I added a two inch strip of pinked medium weight finish tape to the square foot of fabric. An eyeball inspection of my model IV suggested about that much tape per square foot was on the finished airplane. Many of the tapes I used were one inch wide - false ribs and empennage ribs. The weight of the finish tape includes the weight of the Poly brush required for attachment. I took the liberty to add the same to the Oratex weight per square foot as that covering process also uses finish tapes. The weight was determined by calculating the weight of a 2" wide strip of the fabric based on John's measured weight.

My current Model IV has two colors. 100% of the surface is covered in Insignia White - as in the measured sample - as a base coat and an estimated 50% is painted in Lemon Yellow for the overall scheme. The numbers for the white is measured from the sample and the yellow is calculated as an estimated percentage of the white. This was to give me an estimate on the fabric weight for my personal airplane. If an Oratex covered airplane had a decorative design added either by painting or gluing on different fabric colors, it would add to the overall weight, but how much was impossible to estimate.

An explanation of the results: The fabric combined weight refers to the sq. ft. of fabric plus an estimated 1 foot of 2" finish tape per sq.ft. The chemicals combined refers to the net weight of each additional layer of chemical - Polybrush, Polyspray and Aerothane - Not including the yellow. This was to compare equally finished airplanes. However the net increase of the yellow is indicated.

The final weight comparison between the Polyfiber process and the Oratex process is given at the bottom in both white and with the estimated yellow weight. The combined Oratex weight includes the estimated finish tape weight.

Finally, I can think of at least one variable that would influence the final weight vs. my measured square foot extrapolation. Possibly reducing total chemical weight by approximately two pounds. It is that not all of the fabric actually applied in the Polyfiber pricess has the finish chemicals applied to the surface because all fabric underlying seams would have none of the brush or sprayed coats of chemical. For example the 3 inch (or more) overlap on the leading edge of the wing would reduce the overall fabric surface by about 3.5 sq. ft. That would reduce the total applied chemical weights by a small fraction over one pound. To a lesser extent there is a half inch to one inch overlap on every foot of seam - leading edge, trailing edge and longeron length. The best way to get close total weight differences is by, as John Pitkin suggests, a manufacturer that uses the two systems in airplanes built to an exacting design and graphing the weights over time - SLSA.

Finally, I was surprised that the weight of the white Aerothane was as high is it was given that the pigment is titanium dioxide.

[Cherrybark]

It seemed useful to post this general information here rather than bury it in my build thread.

Today I had a conversation with Lars, Oratex Tech Support, Alaska. One question was the shelf life of the two component glue listed in their catalog. The instructions for this two component system said to mix the complete contents of the bottles. The factory learned builders were mixing small batches and the lawyers went nuts worrying about inaccurate measurements and liability issues. Now, the glue is only available pre-mixed and the catalog is out of date.

This news led to the obvious question of the shelf life of the pre-mixed glue. If you keep the bottles at a stable temperature and out of the sun, the glue is good for one year. Widely varying temperatures or exposure to sunlight can reduce this to three months.

[efwd]

Good to know. Thanks Carl.
Eddie

[Cherrybark]

Lars used the term, "First Class" fabric, while giving a rough estimate to cover a SS7. I asked, and he said Oratex offers "blemished" fabric. He gave the example of a bug landing on one of the rollers that applies top coat. As the fabric moves through processing, the color coat of the fabric has a blemish spot every "diameter" of the roller until the problem is caught. He says this cheaper fabric is very popular in Alaska because Black Fly season paints the wings anyway.

[bumsteer]

Thanks Carl. Guess I'll do some testing with the glue I have. It shows an expiration date of 12/1/2016 but has been kept in a relatively stable environment.

Rick

[Cherrybark]

Now, what I expect will be the most controversial point from the conversation. I rolled my eyes as he described this idea but, after giving it some thought, and going over the wing with a tape measure, I'm intrigued.

John was able to buy a wider 75.6" fabric and had useful pieces after covering his wings. The fabric goes through processing at a wider width but the edges, damaged by the material handling of the machines, is cut off and the finished width is now delivered as 72" useful. I hadn't read this thread and don't know for certain if the wider width is possibly still available. Let's assume the 72" width, quoted by Lars, is all that is available today.

Back of the envelope calculations here and I'm not completely up to speed on the required fabric overlaps but here goes. If you roll the fabric along the length of the wing, you'll have a roughly 168" x 72" panel and you'll be cutting around 20" of that 168" length as scrap. After covering the top and bottom of both wings, you will have around 56' (yes, feet) of this 20" wide strip of fabric. That width might be useful in covering the elevator but I believe it's too skinny for anything else, short of pre-gluing or other ugly approaches few of us would be willing to take.

Lars' passed along an alternate idea for covering the wings using much less fabric and saving money on this expensive material. Rather than going lengthwise, cover the wing "chordwise". Glue the 72" width of fabric to the trailing edge, wrap around the leading edge, then overlap and glue back at the trailing edge. Three 72" panels is more than enough to cover the wing. You can either trim the fabric so there is a 1" overlap at a rib or do a full bay of overlap and still have material left over. Lars would insist on rib stitching, but you're probably going to do that anyway. And 2" finish tapes completely hide the seams.

Again, rough calculations but this approach appears to save 11' of full width fabric - a very useful piece for covering tail feathers.

Comments are solicited please! And please don't be shy about correcting any miscalculations.

[Corrected typo on width of John's fabric]

[jrevens]

Hi Carl,

The fabric I got was 75.6" wide. I purchased 25 meters (82'). I actually got a little more than that from them. The alternate covering scheme sounds reasonable. FWIW, I was able to cut the 4wing panels leaving a wide enough strip to get 4 elevator, 4 horizontal tail, & 2 rudder panels, with very little waste. I believe I cut the wing panels 46.8" wide, leaving almost 29" for the other pieces. Out of the rest of the fabric I cut all of the fuselage pieces as well as the vertical fin.

[efwd]

Hmmm. I unrolled the fabric the entire length of the horizontal and cut it off. Folded the fabric around the horizontal like a taco shell. Wonder if the remaining length of fabric on the roll will be long enough to cover the wings length wise and the fuselage. Guess I will have to consider using the multi panel method possibly.
Eddie

[Cherrybark]

A few months back, John received fabric with a width of 75.6", but today's factory specs say "71". John was able to cover his tail pieces from the long fabric pieces leftover after cutting the wing panels. A reduction in width to 71" makes the cuts much more critical and might change the layout plans.

In a recent conversation with Paul Mills, Oratex Sales Manager, I asked about the actual width of the fabric being delivered today and mentioned the change. He explained the 71" figure was the "guaranteed flawless finish width of the fabric". The large fabric rolls make several passes through the coating machines and, despite extensive air filtering, impurities do sometimes make it onto the coating. During final inspection, when they find a blemish, they cutout that section of the fabric. Fabric width outside the specified 71" is still perfectly useful but there may be specs or other issues with the coatings that make is less than perfect. Paul said customers routinely layout covering panels so the blemished coating is overlapped by "perfect" fabric then, of course, tapes.

Oratex, being a German company, works in metric but a rough width of delivered fabric remains 74".

[jrevens]

As I explained in a private message to Carl as well as the post on 2/9/17, it should be relatively easy for anyone to cut out the wing panels and leave enough width of material to do all of the tail surfaces except the vertical fin with the remaining strip of fabric. Of course accurate cuts have to be made. Don't waste extra material on the wing panels... it isn't necessary. Take a little time and accurately determine the layout for how you'll cut out the various pieces. The stuff is too expensive to waste. I should have written a book.

[Cherrybark]

Get started on that book John! I would be happy to receive a rough draft in the next two or three weeks!

[efwd]

Yes John, you should have written something....:D
I bet I will be ordering an entire wing panel since I didn't follow the guidance given here. It seems everywhere I referred to with regard to Poly Fiber and Oratex they recommend starting with a small part like the elevator or rudder before moving on to wings and fuselage. I could not have used scrap left over from the wing by following those suggestions. And regarding flawless fabric within the 71".. maybe not. I have located what appears a dab of paint over a small spot where the color coat has come off. Not even a big deal. As I have damaged that color coat myself elsewhere and dabbed a small spot of yellow paint over my damage as well. I found such a perfect match paint that showing a pic of it, you would not find the spot.
I just finished the fabric along the razor back last night and am so relieved that it looks great. I think the fact that I took it on by splitting the panel down the middle helped me out a lot. Fuselage is now covered but now need to tackle the tapes. Not looking forward to the transition of the razorback and the vertical fin.

[Cherrybark]

Just to keep the collection of Oratex wisdom on one thread.

I think the gentle curves of the stabilizer made it easiest to cover. The sharper curves of the elevator makes the perimeter finishing tape more of a challenge. The rudder presents the interesting problems of how to cover around the three "pipes" at the bottom, blend in the flat area in front of the cable horns and, finally, do a neat job with finishing tapes. That is the order I would recommend.

[Cherrybark]

When rib stitching the wings, what reinforcing tape are people using with the Oratex system?

[efwd]

Same stuff that came with your Poly Fiber. You can't use the waxed string though.

[Cherrybark]

For those exploring Oratex techniques, here is a link to a thread discussing rib lacing with waxed and non-waxed threads.

http://www.teamkitfox.com/Forums/showthread.php?p=66025#post66025

[bumsteer]

Has anyone ordered the Grade 2 Oratex 6000 fabric? I ask because I just got a quote for some more fabric and the 6000 is now $174.95/yd up from $153.75/yd when I bought some last August. It is supposed to just have minor imperfections which you could probably work around ( if you could even see them). The Grade 2 is 38% cheaper or about $108.50/yd. Out of curiosity I also asked about the degreaser. $16.95/500ml. Not bad but the Hazmat fee of $500 is a bit of a turnoff!!. Guess I'll stick with denatured alcohol or acetone. Thanks in advance.

Rick

[JMH]

I bought the grade 2 Oratex. I've only covered one wing so far, but I honestly haven't spotted a noticeable defect in the two panels I've used. I did see a little defect in a 2" tape, but it's Grade 1. I fly off a turf runway, and there are always bugs on my airplane. I don't wash it too often,(we seem to have bugs all year in Texas) so I'm not worried about my Kitfox when I get it flyable.

John

[bumsteer]

Thanks John. Think I'll give it a try.

Rick

[bumsteer]

Attempted my first try at covering the HS. Didn't like the way the curved tips turned out so off came the fabric. If anyone doubts the holding power of Oratex glue, try getting the fabric off. Anyhow I sent Lars an email but no response yet. So if any of the guys using Oratex have redone something, what did you use to remove the cured glue? Tried acetone and MEK. Both seemed to work but slowly. I'm under the impression that the Oratex glue remover is for uncured glue. Tried a search but a little time consuming and didn't find anything. Thanks in advance for any help.

Rick

[efwd]

Okay, I seem to recall that the recommendation is in the documents that Lars puts on his Web Site. I believe it was wrapping with a cloth and then saturating it with Vinegar to soak for awhile. Honestly, I don't recall, possibly it was for uncured glue.

[bumsteer]

Thanks Eddie. Are you talking about the Better Aircraft (Oratex) website or does Lars have his own which I haven't seen? Thanks again.

[bholland]

I have had good luck with using the water and vinegar at 4:1 as recommended by Lars. The more you soak it the better it works. I have only done this on glue that has been on for under 24 hrs after heating. It also seems that heat helps soften the glue where you can slowly peel it off. I have heard that after the 24hrs there is a cleaner that they sell that will remove it but it is expensive having it shipped.
I to have just began the covering with Oratex and I actually used 2 practice kits trying to figure out how to work with it. It was very frustrating at first but it has gotten much easier and is actually getting satisfying to work with it. I have definitely gone from thinking I made a mistake to being happy I went with it.
If your interested you can view more on mykitlog.com/bholland and of course all the guys on this site have been the best resource.

Brett

[efwd]

Better Aircraft site. Its possible that he sent me an attachment in an email once I ordered. I no longer have those. Accidently put them in the trash.
Eddie

[Cherrybark]

I used the vinegar and water solution to cleanup glue that hadn't been heated. Didn't know it would work on recently activated glue. Used acetone to cleaned up a small area of older, activated glue.

Rick, private message your email and I'll send the unofficial instructions that Lar's wrote. It's a less stilted, more real world, description of how to use the materials. It's an ongoing document and Lars would surely email the most recent version if you email him. But probably little has changed.

[bumsteer]

Thank you gentlemen. Carl PM sent (I hope)

Rick

[Cherrybark]

Info sent Rick.

It finally sunk in that Lar's "Short Version" of the Oratex instructions could be attached to a post, so here they are. Lars says this is his "Technical German/English" writing style. You'll find his instructions are much more practical than the factory manual.

[bumsteer]

Got the info Carl. Thank you very much!! I'm hoping the vinegar/water mixture works. In rereading the company manual on removing fabric it does say the glue remover should remove dried glue. The remover itself is not that expensive, but the Hazmat fee is probably insanely high. I was going to get their degreaser and the fee was $500. Again I thank you for the info.

Rick

[bholland]

I stumbled across another method of removing glue from Oratex. They now provide a Primer that you can apply to the covering prior to applying the tapes. This primer is some sort of granules that you mix with pure Acetone, and after it sits for 12 hrs (I think), you can wipe it on to the areas that are getting taped and you don't need to worry about it getting outside the tape lines because it does not leave any residue. I had one piece of tape shrink slightly leaving exposed glue. I figured I would have to use the vinegar water method and not get it completely clean. After sleeping on it I thought I would try the primer and it worked very well 12 hrs after I initially applied the tape. I then tried it on some glue that had been heated several weeks prior and it softened it as well. I would say that it would be a mistake to try this anywhere but where you are removing glue for cosmetic reasons only, since it probably would damage the glue bond.

[Northof49]

I used isopropyl alcohol to remove the excess
glue on my tape & over lap lines . It took a bit of rubbing
But got most of it off .
Mike

[bumsteer]

Like many of you who have used Oratex, I chose to cover the tail feathers to see how I would like Oratex and the application process. After a steep learning curve and getting the tail feathers covered, I'm moving on to the wings and fuselage. To those ( John, Eddy, Carl, etal) do you remember about how many yards were required for the wings and fuselage? Thanks in advance for any help.

Rick

[Cherrybark]

I used Google Sketchup to layout the cutting plan for my project. Laying out the wing panels this way "wastes" a lot of fabric and others may have cut some of the smaller pieces from this fabric. Lars cautioned against cutting close to the finished dimension and, as you have seen, the fabric is slightly shrinking while you heat activate the glue. I ordered 30 meters of fabric. As you may have already learned, when you order several yards (er, meters) of Oratex, the factory is likely to offer you various combinations of roll lengths to complete your order. One of my selections, shown in the cutting plan, was three rolls totaling 35 meters. Oratex is very generous with their fabric. Each of the rolls had more fabric than shown on the label - up to two extra meters in one roll. Of course, you can't count on this. I had plenty of fabric left over. You might roll out all of the fabric and measure before you start cutting.

Unless Lars has finally convince the factory to stage product in Alaska, you will be paying FedEx a lot of money if you have to buy additional covering supplies. I originally ordered 3 liters of adhesive and had to order an extra liter towards the end. Three liters will probably do the job and some of my pre-glue paint job ended up using more glue than necessary.

Hopefully you can get an estimate of the required fabric by looking at the drawing. I'm happy to send you the SketchUp (free software) file if you like. Please, please, please double check these measurements against your plane.

After completing the tail feathers, you'll enjoy covering the wings.

[bumsteer]

Thank you very much Carl!!

Rick

[Clark in AZ]

I am new to the covering scene, either Polyfiber or Oratex. I took an EAA Polyfiber workshop but then decided to cover my SuperSTOL with Oratex. Anyway, I've been helping a friend cover his Kitfox with silver Oratex and we did not achieve the results in your pics. You did an incredible job covering the rudder and elevator! It shows me it can be done correctly. I wish you would share some of your techniques for getting the smooth edges on the top of the rudder and the tight curves of the elevator? How did you cut/lap the fabric and tapes and get them to lay down so smooth? Thanks for sharing!

Again, excellent job!

Clark


As promised, here are some pictures of my initial foray into Oratex land. I haven't had much time to work on it, but I started with the rudder (which is now complete & ready for flight), and am now working on the elevator. I'm getting more comfortable with the process, & I like the look.

[tracstarr]

I'm nearly done my oratex now. Only edge tapes on the elevators and rudder... which I've taken off about 3 times now. I just can't get things to sit nice on the curves. The rest mostly turned out great. I've got a lot I'd like to add to this thread, but I'm not prepared to write it all down tonight.

But IMO the biggest help is a second set of hands. Second biggest help, don't be scared about screwing up - otherwise you won't learn. You can do it on your own as others have shown, but it's far easier with help, especially on the smaller bits and curves. I actually started on the wings and fuselage as they were less complex IMO.

One thing I noticed when doing the tight curves which require lots of heat.... make sure you hold the fabric in place after heating it up otherwise your perfectly nice material on that curve will slip and wrinkle. It needs to cool to keep the grip. This will make you very upset.