Foam/Veneer Wing Construction Question

Hi Guys I've been away from the sport for some 20 years and my kids bought me an ARTF kit for Xmas to get me into it again. This kit recommends joining the two halves of a Styro Foam/Veneer wing with PVA glue and two 3mm ply braces - and thats it. When I was doing this before, we always joined the foam wings with epoxy resin glue and then followed up with a fibre glass and resin bandage over the centre section of the wings. Has this sytem faded away? Is PVA and ply strong enough to withstand the strain of (simple) aerobatics? or should I use the old tried and trusted method?. Any replies will be welcome Thanks

Reply to
Bill Morrison
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If it wasn't strong enough for the intended use of the plane, I doubt the kit would be sold for long. For added insurance you can always add a strip of glass cloth on the joint.

Reply to
Paul McIntosh

I like the "old" method. I don't like sharp things like plywood impaled into foam cores. They become knife blades under stress.

I join my foam core wings with spray-on contact cement. Yea, It's weak, but think about it. Styrofoam is very weak anyway, and the contact cement ensures no surprises in the morning.

I wrap wing joints with .75 Oz glass cloth, using 3 layers. First layer, say

4" wide, then a 6", then 8". I use slow cure epoxy for best strength and a nice smooth joint. This makes a feathered edge that fits the wing saddle nicely and leaves no hard cutting edges, and a bonus is there's no ugly bulge or step beneath the covering.

You must realize kits are made as economically, quick building, and idiot proof as possible. If you have the skill to make a nice fiberglass wrapped joint, it will only add to the quality of your model. :)


Reply to
Bob Adkins

My personal opinion - while PVA (aphylatic resin, white glue, etc) has a 3000 pound (or so) bond strength - I would not feel comfortable without the glass around the center.

Is this a fuel or electric? If fuel, stay away from PVA - it will be dissolved by fuel.

The strain at the center join can be enourmous at the bottom of the loop - I would not want to see you watching the wing halves flutter gracefully to earth while the fuse pounds a large hole.

Like I said, just my opinion.



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