Adhesives

[Rotten]

What are some of the adhesives to use to skin a foam wing?

Can I substitute Titebond for Sig Super Weld?

Thanks

[peabody]

Titebond thinner with water to the consistency of milk has worked well for me. I recommend saning both foam and sheet very well, and coating (one or two) with dope onto the surface of the sheeting to be bonded....lots of weight on the core set while waiting for the glue to dry......

[Rotten]

Thank you for the speedy reply, I believe I met you Sunday, I was the guy with Neal Beekman, It was a good event with lots of good stuff. If I was to use Z Poxy to sheet the wings I need to dope the foam first?

[Ron King]

I prefer epoxy, but the secret is to scrape off as much as you can before you attach the skins to the core.

Prep is the same as Rich described: sand both the cores and the skins, then vacuum up the foam dust. I paint two coats of nitrate dope on the INSIDE of the skins. This keeps the epoxy from penetrating too far. Then mix your epoxy (I use the 20 minute Finishing stuff. It actually takes hours to cure.), spread it on the skin, and start scraping. The surface should look slightly damp. If it looks wet, you should scrape some more. A 700 square inch stunter only needs 5/8 ounce per wing half.  

I use vacuum bags, but you can also use lots of weights and a flat surface. I like to sheet my wings after dinner, then shove them into the vacuum bag, and let them cure overnight.

Hope this helps,

Ron

[Mike Spiess]

Thank you for the speedy reply, I believe I met you Sunday, I was the guy with Neal Beekman, It was a good event with lots of good stuff. If I was to use Z Poxy to sheet the wings I need to dope the foam first?

Rotten NEVER PUT DOPE ON FOAM unless you want them to turn into a sticky melted mess

[Randy Powell]

I might note that it's easier to put "lots of weight" on the skinned wings if you do the sheeting before the wing is cored.

[steven yampolsky]

What are some of the adhesives to use to skin a foam wing?

By far, the best way to attach a skin is Gorilla Glue. It doesn't just grab onto the foam surface. It digs into the foam to make it impossible to detach the skin. Amazing stuff. Light too.
Someone clued me to it on another web board and I haven't looked back. Here's how you do it:

1) prepare skins and foam surfaces as you normally would.
2) mist some water on skins and foam cores.
3) put cores aside, cover the table with saran wrap and place the skin on it.
4) spread Gorilla glue on the skin. The glue surface will become shiny.
5) using an old credit card scrape glue off balsa skin onto saran wrap.
6) This is key: Keep scaping until glue surface no longer shines. The surface should have a dull look.
7) attach wing skin to foam wing and weigh it down like you normally would.
repeat steps 3-7. make sure to replace saran wrap as excess glue may get on to the wrong side of the wing skin.

This approach ensures ligthest wings and strongest bonds. Talk about win-win situation.

[don Burke]

Remember with GORILLA GLUE, it expands significantly while curing be sure to use enough weigth or better yet the mentioned vacuum bag.

[peabody]

I think that Windy still sells videos of Scott Smith and he using both spray glue and epoxy....

[linheart smith]

Steve,

What is the open time on your glue method.
Sometimes I like to take a nap during glue up.


 

[steven yampolsky]

Remember with GORILLA GLUE, it expands significantly while curing be sure to use enough weigth or better yet the mentioned vacuum bag.

This is the reason why Gorilla glue is so much better for skinning wings: it expands! The glue expands into the areas of least resistance i.e foam. Also, note that instructions mention scraping glue off until the surface looks dull. With any other glue, this would guarantee weak surface-only bond.

A local master builder(builds RC jets) did an experiment: he gorilla glued some 1/16 balsa to a block of foam, let it try, then dissolved the foam with acetone. The glue looked like a root systems of a tree! There is no way that skin would separate

[steven yampolsky]

What is the open time on your glue method.
Sometimes I like to take a nap during glue up.

Not sure what the open time is. I have never seen it gel in front of me. I usually attach skins in the evening and go to bed. By morning, they are cured.

[Will Hinton]

I use Gorilla glue in the building of my custom guitars - hence all hardwood.  I have also used it on foam wings to install the center spar, and for the reasons Steve mentioned; it expands.  However, as to the working time, skip your nap!  Depending on how much water you hasppen to spray, it can really accelerate at the time.  I've been clamping up a guitar and had it start to expand out of the joints before I got it all clamped.  It did no harm, but sure made me nervous at the time.
If you really get a very light mist with your water, that's the best.  It is amazing stuff, and as stated, quite lightweight.  I think it's the best there is for foam, whether building or covering.
Will

[Leester]

Also a tip Crist Rigotti told me about, take the core cut outs and wrap with 2 thickness'sssssss of newspaper and tape tight then put back in the wing. Makes for a tight fit and the cores won't sag when you weight them down.

[steven yampolsky]

Also a tip Crist Rigotti told me about, take the core cut outs and wrap with 2 thickness'sssssss of newspaper and tape tight then put back in the wing. Makes for a tight fit and the cores won't sag when you weight them down.

Good tip! I'll use it next time!

[john e. holliday]

I used the Gorilla glue when I laid up the profile P-Force fuselage and clamped to a flat metal plate, as stated if the glue starts oozing out while clamping, you left too much glue.  I have never had a fuse as stiff as this one once the glue cured.  I does sand easy tho.  Have fun,  DOC Holliday

[Jim Kraft]

Anyone use gorilla glue for glueing doublers to profile fuselages? Might be the hot deal. I have never used it for anything, so have no experience with it.

[john e. holliday]

It works great and is lighter.  DOC Holliday

[Iskandar Taib]

There's probably little need to mist the parts, unless it's winter - there's plenty of moisture in the air and in the wood.

[john e. holliday]

I take a damp rag and rub it over the surfaces to be mated.  Have fun,  DOC Holliday