Project 5 build thread

[jiott]

I would think you want finishing tape on the elevator and horizontal trailing/leading edges. These are areas very vulnerable to hangar rash and an extra layer of fabric would help a lot.

[bumsteer]

Alex

It's been my understanding that if you have a seam then use finish tape. Don't quote me but I thought I heard Lars with that advice but can't remember where(maybe Oshkosh). Besides, if that's where the errant glue is, it'll now be covered.

Rick

[alexM]

I really appreciate the input, thank you. I can say I've got tons of 50mm finishing tape and a big wide roll too. Now that I look at it, the wide stuff should be used along the hinge line. If I used 50mm there it wouldn't even cover the seam overlap.

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Tossed the Airstreaks on my new gear. Definitely gave it some lift.

[alexM]

Interesting update to the Oratex process.

When I was covering my elevator I poured some of the adhesive into a cup so I wouldn't be contaminating it. I noticed some wispy clumps starting to form in the jar so I thought my adhesive might be toast and that I would need to order more after all. For those not using Oratex, the adhesive is not cheap.

I sent an email to Janina at Better Aircraft Fabrics to get a quote. Instead of that I got a call from Lars, who spent about 30 minutes with me on the phone. He told me that the wispy formations are normal, and they form because there is an air gap in the bottle when the lid is on. The air exposure causes the formations to begin. It looks sort of like the way ice forms on the edge of a puddle. He did tell me that if you get round globs it is a sign the adhesive is going bad. My last order came with some paint filters, so I asked Lars if those were intended to be used to filter out any clumps. He confirmed that is why the factory sends them, but that the weave of the filters is much to tight and prevents perfectly good adhesive from flowing through (which I also noticed).

Bottom line, it's all about the peel test. Filter out the clumps, do a test. If it passes, you're good to go. Pretty refreshing to have a company not sell you something you don't need.

Edge tapes
Over the weekend I got out my rolls of finishing tape and stared at my elevator for a while. Rather than experiment on my elevator I decided to get some practice. I found a board the same thickness as the small diameter elevator tubing, traced one of the corners onto the board and cut out the shape. Then I used my router to round the edge to simulate the elevator. I practiced the routine a couple of times. The tape is much thinner than the Oratex 6000 and by my second try I was getting it nearly perfect. I was able to peel the tape off before it cooled down so that I could re-use my wood piece.

I also obtained some 3/8" copper tubing which I have bent up to also mimic the corner radius of the elevator. I really wish I had done this prior to covering an actual airplane part. My current elevator is "good enough" but I can see that with some practice I could get excellent results. I hoped that Lars had some classes coming up this year. He said that so far they do not have plans for any class in 2021. They're going to Oshkosh but he said he doesn't like to run classes there because everyone who shows up has sunscreen and hamburger grease on their fingers, which makes quality work very difficult.

I'm currently on the fence about whether I peel the covering off my elevator and go for perfection, or whether I move forward. I just had Heather quote a SS7 elevator (which has more chord than the series 5), and just swap out later. Very tempting to go that route. I already know the elevator will fit inside my car, so no need to drag a trailer to Idaho this time.

Lars recommended that I join his Facebook group for BetterAircraftFabrics because he posts a lot of do/don't examples, videos and discussions with other builders. I'm already finding it a valuable resource.

[alexM]

Oh, a bit more from my call with Lars. The cleaner used on the installed fabric when you prepare to glue on the overlapping piece is Isopropyl alcohol. No need to overpay for a mystery solvent.

More importantly, when I asked him about (possibly) removing Oratex covering he told me to set my heat gun at 450-480F which would cause the glue to fail but not burn the fabric. To get the cured, activated adhesive off of the structure he said to use Citristrip. I see it available from Home Depot for $7.99/gallon so it's cheap. He says it's lousy paint remover but the one thing it does well is remove Oratex Hot Melt Adhesive.

[Denalifox]

Alex, one tip, if you ever have some not so great spots say around the radius on the horizontal and you plan on covering with 2" tape. Use adhesive to fill on the "voids". Since tapes are 600 and thinner they show everything underneath. Filling voids and stepped transition points with glue help hide some of those.

[alexM]

Alex, one tip, if you ever have some not so great spots say around the radius on the horizontal and you plan on covering with 2" tape. Use adhesive to fill on the "voids". Since tapes are 600 and thinner they show everything underneath. Filling voids and stepped transition points with glue help hide some of those.

I wish I had a chance to learn all these tricks before I got started. I plan on practicing more on test pieces to see if I can get my skills up.

The brown truck showed up today
PXL_20220209_002158516.jpg
That is my Sandia STX 165 R mode C transponder. It's about half as big as it looks in the ad pictures (my pocket knife is pretty small), which is fine by me. After zero inventory for a while, Aircraft Spruce sent me that over two weeks before it was expected - and at an un-adjusted price I might add. My plan is to put this aft of the seat pan somewhere. This R version is headless and will be controlled by my MGL MX1 displays, and ADS-B in/out will be handled by my Echo UAT.

So all my avionics, engine monitoring etc expensive bits are on hand. I don't have my wing tip lights/strobes or my landing lights but I know what those parts will be. I think I can officially start planning my electrical layout and wiring.

[alexM]

I slapped together another video, mostly showing the schooling I'm getting in Oratex.



My plan is to get really good at it so I decided to do another test piece. Pretty easy to make and gave me lots of practice on those tricky Kitfox elevator corners.

[alexM]

We had a couple of days where it was probably warm enough I could have at least got the covering on the bottom of one wing, but now we're back to night time lows in the 20s and I've got plenty of ways to screw up the covering job without those pressures.

So I decided to turn my attention to things I can do inside. One was this fake image I put together to serve as a thumbnail for my videos. I used DaVinci Resolve which I edit my videos with to "photoshop" a Verner 7 cylinder engine onto my fuselage. I'd like to say I also photoshopped the the clutter in the background, but my hangar is a bit of a mess currently. And by currently I mean for the past couple of years.
7U rendering.jpg
I had to find a picture of a 7U that was at the same viewing angle as an existing fuselage picture and got pretty lucky.

And speaking of fake, another indoor activity which could be performed would be to convert my Solidworks model into the mock up/test mule for my instrument panel. I have the factory supplied panel and I have my avionics so I decided to sacrifice the factory panel. I could have used a sheet of plywood with some brackets along the bottom but for the final product I will have a panel CNC cut with all the engraving, so this seemed like a good use for the panel I have.
Kitfox N527KF Instrument Panel Assembly Feb 22.jpg
Above is one of the design iterations I came up with, and which I went back to. I just like the simplicity of the switch logic. So I used masking tape and got out my measuring tools and created the layout on the aluminum piece. For the rectangle cutouts I knew my dremel tool would not be up to the task because you have to hold the tool at an angle and you're doing it all freehand. So I invested in a 3" cutoff saw which had a fence making it like a Skilsaw with the blade perpendicular to the surface, and clamped straight edges to help guide me. Holy smokes did I butcher the job. There's a reason I spent all those years doing CNC work. I'm glad I wasn't counting on putting this panel in my plane!

I have a picture of the bare aluminum piece but I'm not going to post it. People break out of prison and do better metal work. Suffice it to say I filled some gouge marks with Hysol and primered the panel before anyone could see it.
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The MGL MX1 displays have a very narrow flange on the sides so they don't cover up mistakes. You can see where I put in the hole locations for the switches and breakers but intentionally left them undersized until I have physical parts in my hands. So...

While I was waiting for the Hysol to cure I went to the B&C website to put together an order for switches. Doing that has already initiated my first revisions. I had expected to find a single pole, single throw OFF-(ON) switch to use for starter engagement but the closest I'm finding on the B&C site is a dual throw (ON)-OFF-(ON). I suppose I could leave one side INOP or wire it so you could push switch either way for the momentary (ON) feature. What I will probably do is ditch the switch and the guard and use their S895 push button switch with the shroud, which I may already own an example of.

Then there's the circuit breakers. I know Eric warned me that these would add up quickly, and at $27/each that is no lie. The obvious solution is the automotive style fuse blocks which have the added benefit of having the bus bar built into them. I'm not thrilled when I see those fuse blocks visible on the panel so if I go that way I will either bury it under the panel where some gymnastics are required to access them on the ground, or I'll copy some other folks and put a small cover plate on the panel where I have my breakers shown and hide them that way but still make them fairly easy to access. Decisions!

I do occasionally see people selling Klaxon breakers on Barnstormers for more like $5/each so I'm going back through the spec sheets for my electrical components to fine tune my amperage values.

[Eric Page]

I had expected to find a single pole, single throw OFF-(ON) switch to use for starter engagement but the closest I'm finding on the B&C site is a dual throw (ON)-OFF-(ON).

Alex, the switch you want is the S700-1-8. It's a SPDT ON-NONE-(ON). Just wire ground to the center common contact, ignore the maintained ON contact (that will be your OFF) and use the momentary (ON) contact to energize the starter relay. The S700-1-8 will look and function identically to a SPST OFF-(ON).

Depending on how your ignition and starter are wired, you might consider the S700-2-51. It's a progressive transfer DPDT OFF-ON-(ON) switch. That means that in the ON position, the ignition is powered, and in the (ON) position, both ignition and starter are powered.

The S700-2-50 (SPDT OFF-ON-ON) performs a similar progressive function for battery and alternator (first ON for battery, second ON for battery and alternator).