Repairing fabric tear on plane covered with non-standard paint

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MontanaMan

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Hi:

I have a J3 Kitten ultralight that was covered with the non-certified 1.7 oz. fabric, and painted with Marine paint, called "System Three Marine Coatings" WR-LPU. It is described as "a two-part, water-based linear polyurethane enamel." It comes in 2 parts ... a can of paint and a bottle of "cross-linking material"

The Primer used was System Three WR-155, a "Waterborne 2-part epoxy primer." Apparently those two (the topcoat paint and primer) are designed to go together as a marine covering system by the company System Three.

So ... I have a rip in the fabric that needs repair, and I'm not sure how to go about it. What glue do you think I should use?

I've never covered a planed before, and have never repaired a tear in the fabric.

Any help/advice would be much appreciated.

Thanks!
 

Victor Bravo

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The Stewart Systems glues and coatings are supposedly compatible with almost anything. Since it's an experimental you have no problems with compliance or inspection, only what works and is safe.

How big is the tear, and where exactly is it?

Several of us here have various levels of experience with fabric, and we will be glad to advise, and keep you out of trouble.
 

challenger_II

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From what I can find, System Three and Stewart Systems are not related.
Perhaps, researching the System Three site for marine coatings may shed some light:

 

Dana

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System 3 and Stewart are indeed unrelated, but Stewart products can be used to repair other systems; the procedure is in the Stewart manual. Basically you need to sand down to bare fabric, glue the patch on with their EkoBond adhesive (some people use 3M 30NF), followed by their EkoFill, then your primer and topcoat.

Do the stitching and patch sizes per AC43-13.
 

TFF

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I would go with the Stewart’s glue too. I just used it on a Cub to reattach some fabric coming loose.

There have been a few RC model airplane paints on the market that fit the System 3 paint description. May have been used as their basis. It’s always been in the back of my mind as an option.
 

Dan Thomas

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Sanding down the finish is risky. One pass too many with the sandpaper destroys the fabric. Most folks use some MEK on the inside of the fabric to break the base coat loose so it can be peeled off, but this one has an epoxy primer that is going to be really stubborn. And MEK vapors inside a wing are an explosion hazard, what with the static generated just by working around fabric.
 

TFF

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Go read all the covering manuals for all the brands and see the consensus of how to do it. 43-13 has ways too. 43-13 will have you sew the rip and then patch. Most of the others are simplified with just a patch. It matters where the rip is and if you can get behind it or if it’s all from the top. Infinite answers without specifics.
 

Victor Bravo

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The real-world answer to the OP's question will be determined by the answer to how big is the tear and where is it. For a "screwdriver poke" hole on a 60 mph J-3 Kitten, a small "dollar patch" can probably be glued on right over the paint if the paint is bonded well to the fabric. A long straight rip on the underside of the wing in the propwash will need stitching, but then a pinked tape might be fine just glued down over the "structural" repair of the stitching.
 
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