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Rib stitching

15 posts in this topic

Posted

Hi, not to the point of covering , but wondering if the wing is stitched do I have still use poly talk on the ribs.  Model 3 under camber ribs.

thx

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Posted

Hi, not to the point of covering , but wondering if the wing is stitched do I have still use poly talk on the ribs.  Model 3 under camber ribs.

thx

I just finished covering my model 2 and I glued to the ribs and rib stitched them. I used the Stewart System glue which I believe is quite a bit stronger than Poly-Tak.

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Posted

I've done several sets of Avid and Kitfox wings that I stitched.  I glued the fabric to the wings as I installed it and then stitched later.  Just seemed to keep everything in place.  Just seems to make sense especially on the undercambered side.  I've used poly fiber products on all my covering work.  JImChuk

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Posted

Thanks, I’m going to use poly fiber also. I recovered my tcraft a few years back and it turned out great.  I used Martin clips on the wings, which were very simple, but stitching would have been a cleaner looking end result.

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Posted

My Mk IV has poly fibre, and the undercamber wings, and was not rib stitched by its builder. It has 800 hours, and was flown first in 1996, and not one fraction of an inch of any rib is disbonded.

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Posted

What was a shock to me was the first time I removed the covering that had been done with poly-fiber. It popped off with very little effort, cleanly I might add. And I've used poly-fiber for 30 years. Would have used it again but decided to try this newer system due to the smell and health concerns. One couldn't go wrong with either system, since they both do a good job.

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Posted

JFYI Stewart's glue turns to goo if fuel touches it, it sure was nice to use but I will not use it again for that reason. 

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Posted

JFYI Stewart's glue turns to goo if fuel touches it, it sure was nice to use but I will not use it again for that reason. 

Well that would make the decision for me.

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Posted

I'll give that a try with wet glue. It didn't have any effect on what was dry, cause I tested my tank installation and spilled a bit of fuel on the glued fabric and it didn't change any or release any fabric.  But MEK will clean it off your hands and metal parts. But I am curious to see if this is true, if it is, it could be bad, especially around the fuel tank wing area. I don't know of too many pilots or line crew that don't spill a few drops of fuel when filling wing tanks.

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Posted

Just talked to an experienced Stewart Systems guy and I asked about the fuel problem. He said it was the ethanol in the fuel that would soften the glue if left in contact with the fabric. Regular fuel or AV gas would not affect it.  Of course ethanol will do the same with poly tak and poly brush also. But with both systems, occasional contact with gas will not affect it, only continuous submersion would. But I am still going to do a test panel.

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Posted (edited)

Allen it was not ethanol, just Pure Gas 91. I would  use the scientific method and try it for yourself before betting your fabric job on it.  It is on the backside fabric where it is unprotected by paint.  I developed a small leak around the header tank and the dollar patch wrinkled and pulled off without effort.  I was pretty disappointed because I did like using it on a fabric repair job.  Seems like Ed said something about the same problem with Stewart's several years ago but it may have been something I read elsewhere.  Anyway check it out, I threw the major portion of a quart, I had left away.

Edited by wypaul

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Posted

Just found this on shortwingpiper.org I am sure that you can find many, many more of these stories because it is a real problem. 

This is just a comment for information to those doing fabric work. I thought I would be starting up 03C this week but instead it is coming back apart. I just got it assembled and now a fuel leak has destroyed the belly. Yes I should have found the leak at the fuel valve but that isn't the big problem. About a pint to one quart,(at the most), of gas leaked, soaking the insulation in the left side and belly some running down the gear leg. The Stewart ekopoly peeled loose and the glue joints all came apart as well,(stewart ekobond), the glue/paint had been on about six months. I know my fault with the leak,but, I have never had damage like this over an eight hour period, with dope or enamel before. I thought I would try something new with the waterborne urethane and sure wish I had stayed with Randolph products that I understand. My point is if you want to try this stuff I recommend starting with some test pieces to play with and see how it holds up for you before doing your whole project. I am not saying that I did not do something wrong in the application. I don't think so but even if I had the glue for instance is applied straight from the bottle and it melted in the gasoline. I have never seen Super Seam melt from an overnight gas leak. Same with the paint peeling off I've seen lots of fuel stains on dope and enamel finishes but not lifting and peeling from a fuel leak. Thanks for putting up with my venting,I work alone you guys are my help, it's been 18 months and I just went back two. This thing is a friggin' albatross, the bird kind not the Grumman!

Stewarts are aware of this problem and do not like to talk about it for some reason.

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Posted

I did try a test on the eko bond and 93 oct gas. Spilling some on the fabric and wiping it off had no effect on the bond. Soaked a strip that was glued in a can of gas for about 3 hours and it did pull apart with not much force. Guess the lesson is not to soak a wing in gas or dip the fuselage in a gas tanker. This was with no other coatings on the fabric except the glue. Will probably go back to Poly-Fiber is I ever recover again. Don't like the stuff but in 30 years I never had any issues with it.  But I have already covered my wings and tail with Stewarts so not going back and redoing them. Only major issue I would see is if a wing tank started leaking or one had a line rupture and dumped several gallons of gas in the wing or fuselage. Don't know why the FAA would approve an STC for Stewarts if this is the case.

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Posted

The way it sounds if you have a fuel leak your probably screwed but for normal use you are just fine with the system.

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Posted

That appears to be the main thing to be watchful of. A fuel leak if not caught in time can cause a serious problem. A normal fuel spill wouldn't be a big concern as in filling a wing tank and spilling a few ounces.  But then, I never done the same test with poly fiber  as in soaking it in gas. Evidently it has more to do with the crappy gas we have to buy than with the covering system. Use 100LL and you have lead to deal with, use auto fuel and who knows what kind of issues arise. Has anybody ever tried clear aerothane over Stewarts?  I know its some tough stuff.

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