John Evens
Arvada, CO
Kitfox SS7 N27JE
EAA Lifetime
Chap. 43 honorary Lifetime
Nice work!
I like the photos, shows good detail.
Does Oratex have available a reinforcing tape ?
I know the ribs of the Kitfox cap strips are wide as compared to the 1/4" cap strips that are used with wooden wings.
Lacing shows a lot more insurance against fabric peel under lift load.
Completed my Classic 4, May 2003. It had std wings. speedster tail.
912 UL Rotax. Sold to a person in Spain.
Completed a Skybolt December 2018
S7 STi O-320 currently flying
I had a lot of experience with Solartex with 1/3 rc planes. Loved it. As long as you liked the matte finish, which in scale ww1/ww2 warbirds was nbd.
In my case I already had the fabric that came with the kit. I never have worked with Polyfiber before. After splurging on G3x avionics and other stuff, it was hard to pull the trigger on the Oratex. But adding it all up, the chi-com paint booth, the 5 stage sprayer/paint sys., self contained air system, and the chemicals/Aerothane paint - I'm about @ $5000.00. The Polyfiber manual was easy to understand and all my "mistakes" were easily addressed. I have prior experience painting several cars and boats in polyurethane and two part acrylic enamels. I already had all the safety equipment.
I'll be able to reuse all this equipment painting my two older classic cars. I'll sell the lot of it down the road to recoup even more of the costs.
"Somebody said that carrier pilots were the best in the world, and they must be or there wouldn't be any of them left alive." Ernie Pyle
Brett Butler
Flying: N46KF, 1998 Model 5 Outback, 912ul 110hp, G3x with 2 axis a/p, Beringer wheels & brakes, SS7 firewall forward, NR prop, Custom paint
I have an Oratex application manual that details instructions for installation. Not sure if that's what you're looking for? It's from Lanitz (the Parent of Oratex) not BAF though. It can be found here: https://www.lanitz-aviation.com/downloads
Hope that helps.
🇨🇦CANADA
Flying | SS7 | G3X | Edge 912
So I for one cannot believe the weight savings claims for Oratex so I cut a 12" x 12" piece of the polyfiber covering off of my horizontal stabilizer of my project airplane. This airplane is a Kitfox 4 that flew for 20 years and this is the actual fabric from that formerly flying airplane that was finished through white. The finish appears to be about a minimum number of coats but you definitely can't see light through it, so is not too few coats. That 1 sq ft of fabric that incidentally also had 2 12"x2" tapes that were over the stabilizer ribs and the fabric including those tapes weighed 0.75 ounces. I then calculated the area of fabric actually on the airplane in my CAD program. The total area of fabric actually on a kitfox 4 works out to 320 sq ft broken out as follows:
Wings 4 panels (top and bottom) at 46 sq ft each = 184 sq ft
fuselage top aft of turtledeck = 8 sq ft
fuselage bottom = 28 sq ft
fuselage sides including fin and rudder 2 pieces = 33 sq ft x 2 = 66 sq ft
horizontal and elevator (top and bottom) = 17 sq ft x 2 = 34 sq ft
total fabric area = 320 sq ft
320 x 0.75 oz/sq ft = 240 ounces = 15 pounds.
Now lets be conservative and say that with overlaps and tapes we bump that up 10% for a total fabric weight of 16.5 pounds using polyfiber with minimum coatings.
Now lets compare to oratex. Their website says the Oratex 6000 fabric weighs 0.459 – 0.524 oz/ft² so lets use 0.5 oz/ft2.
320 x 0.5 oz/sq ft = 160 ounces = 10 pounds, and if we add that same 10% factor it comes in at 11 pounds. Weight savings = 5.5 pounds.
for Oratex 600 which they claim is 0.301 – 0.4 oz/ft², using 0.35 oz/sq ft:
320 x 0.35 = 112 oz = 7 pounds, then the 10 % makes it 7.7 pounds. Weight savings = 8.8 pounds
So while there is obviously weight savings that can be gained using oratex it is not the wild claims of 20-30 pounds unless you are comparing to a polyfiber finish with way more coats than necessary. The finish that was on my project airplane was what I would consider a utility amount of cover and aesthetically I would rate it at least as good as the oratex airplanes I have seen.
This post was mainly to debunk the wild weight savings claims, but I'll give a little more on my decision for how I will cover my project Kitfox IV rebuild.
I myself considered Oratex even though I am not a fan of the finish appearance but the cost was too much. I have covered the fuselage of my Sonerai with the complete polyfiber process and then recovered it after some modifications with a hybrid polyfiber/latex system. I have actually decided to cover my Kitfox project with polyester fabric, using the latex method described at http://www.wienerdogaero.com/Latex.php. My Sonerai fuselage is now covered through silver with polyfiber with a latex color coat (white) and it looks fantastic and has had the latex on it for about 5 years now and looks as good as the day I applied it. I'm opting to go the full latex route for essentially no toxicity and also for lower cost. I have all the materials for covering except the latex and figure I will have about $1500 in covering and paint materials when done.
John Brannen
Morris, IL
Sonerai IIL (Single Seat)
Kitfox 3/4 1050 - Rotax 582 (Back Flying and sold)
Kitfox IV 1050 - Rotax 582 (sold)
Kitfox IV 1200 Speedster - Rotax 912 UL (rebuilt and now flying)
Piper Twin Comanche (Sold)
Glasair 1 FT (Waiting to start)
Hi John,
This issue has been beaten to death on this forum. "Highwing" did a very good analysis quite a while ago, and the info is all here (somewhere). So, here's the issue, from my perspective, with your analysis (and it's a great analysis!)... a Poly Fiber, or any painted system, is potentially an extremely variable job (weight wise). The biggest variables are the type of paint used and the number and thickness of the coats applied, of course. Yours sounds like a pretty light job and not necessarily typical of the average, especially if urethane paint is used. With Oratex you can know pretty exactly what you'll have, every time. The bottom line is that you will save weight with it, but the amount is definitely variable due to the variability of the painted finish it is being compared to. Here is information that came directly 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've had experience with both covering systems and chose Oratex for several reasons... one that may not be real obvious is that I wanted to try something new. I think I was one of the very first to document my use of it on this forum. It's definitely not for everyone, but it is lighter and stronger.
John Evens
Arvada, CO
Kitfox SS7 N27JE
EAA Lifetime
Chap. 43 honorary Lifetime
Just one further point that I meant to make... the 20 or 25 lb. weight savings touted by Oratex are obviously at the "top" of the estimates for marketing purposes. Maybe more importantly, those figures are referring (I believe) to your basic Piper Cub which is a bit bigger than our Kitfoxes, and are possibly based on those numbers that I listed from Poly Fiber - specifically, "A Cub done in Poly-Fiber has 40 to 45 pounds of finish weight." and "A Cub done in urethane can get pretty heavy if you lay on the thick coats. Urethane is not known for its light weight."
John Evens
Arvada, CO
Kitfox SS7 N27JE
EAA Lifetime
Chap. 43 honorary Lifetime
Any one tried this finish https://www.hipecaircraftcoatings.com/
High Performance Aircraft Coatings
No Ribstitching. No Rivets. No Tapes. Fewer Coats.
Substantial labour savings over other Fabric Aircraft Covering System
https://www.hipecaircraftcoatings.com/