Covering the turtle deck

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jklemin
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Joined: Sun Dec 24, 2017 9:24 pm

Covering the turtle deck

Post by jklemin » Sat Jan 06, 2018 7:49 pm

When covering the fuselage, is it necessary/required to rib stitch the ribs of the turtle deck? If not, should anti chaffing tape be used anyway? Thanks John

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taildrags
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Joined: Tue Mar 07, 2017 10:39 pm

Re: Covering the turtle deck

Post by taildrags » Sun Jan 07, 2018 1:46 pm

John; my Piet certainly doesn't have rib stitching on the turtledeck, and from what I can tell from the pictures when it was being covered, there is nothing but Poly-Tak cement between the wood and the fabric on the turtledeck strakes. I can't imagine why it would be needed back there.

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taildrags
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Joined: Tue Mar 07, 2017 10:39 pm

Re: Covering the turtle deck

Post by taildrags » Sun Jan 07, 2018 4:20 pm

John: more information, this time from somebody that knows what they're doing (an A&P friend of mine). He raises the excellent point that the basic rule is that you should follow the recommendations of the manufacturer of the covering system that you're going to use (Poly-Fiber, Stewart Systems, whatever). He also pointed out something I hadn't thought about but have seen on other fabric aircraft with heavy, glossy, or relatively inflexible finishing coats: the paint and topcoats of your final finish can crack over time right along the edges of those turtledeck strakes. Of course you'll want to just ease the edges of the wood with a light sanding before you clean and cover, but he says you may want to put down tapes on the wood before the fabric goes on so the edge of the wood doesn't 'print' through to your finish coat as sharply and crack it. He said he uses white athletic tape on places like this. Fabric goes down over that, and of course you'll also put down fabric tapes on top of the fabric where there's wood underneath.

jklemin
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Joined: Sun Dec 24, 2017 9:24 pm

Re: Covering the turtle deck

Post by jklemin » Mon Jan 08, 2018 9:47 am

:D Exactly what I needed to know. Thanks to you and your friend. John

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Clay Hammond
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Joined: Thu Feb 23, 2017 11:46 am

Re: Covering the turtle deck

Post by Clay Hammond » Mon Jan 08, 2018 12:44 pm

Don't glue to each stringer, only the surround (although I'd say after glueing a stringer tape or applying your first seal coat to the fabric it will probably attach itself anyway. Adding the protective tape will add weight (albeit miniscule). Simply round over the edges of the stringers, I've seen some where it was a perfect radius roundover from side to side. That would give you the "least" amount of angle transfer and "most" surface area over which the fabric is bending (meaning the harder the chine the more likely it will eventually crack, you want to minimize this). Sand it well in between varnish coats so that it is smooth. Cover, shrink, and tape per your covering manual, or otherwise however you wish.

I personally probably wouldn't even tape it depending on the top coat I used. New style poly based coverings have a better give than the older Imron's and such. As slow as we go and being behind the pilot, I don't think the turtledeck would get beat up quite so bad.
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