Bubbles in veneer
 

Flying season will soon be here, so I got an old model out of the attic yesterday. The wings are almost ready for covering, they are pink foam with obechi veneer and the LE and TE are already attached. But there are a number of bubbles in the veneer where it has obviously separated from the wing core.

What is the easiest way to stick them back down again? I'm not the original builder of this model (got it at a swapmeet) so I don't know what glue was used to attach the veneer in the first place. I plan to slit each bubble, squirt in some glue, then press it down flat. Which glue would be best for this? I've only done it once before on another model and it was a pain, it took forever! The one thing I really don't want is to get everything flat, cover the wing, then later find the bubbles popping up again.

Bubbles in veneer
 

Slow setting epoxy is probably your best bet. Put wax paper over the wing and put enough weight on it to press the "bubble" back to the surface of the foam. Be careful that the weight you use does not twist the wing while the epoxy is curing.

Bubbles in veneer
 

I'm a big fan of polyurethane (Gorilla) glue for foam / wood use. You can heat and it will turn to water just like epoxy, but will begin to cure quickly, so make sure it's close to where you want it. The advantage of the poly glue is that it foams up and forces itself into the foam so you don't get any voids.

If you know any diabetics, you may be able to get ahold of some syringes to put the glue into the voids. Fill up the syringe, then run under hot water to heat up the glue. You could also do this with epoxy. . . .

Bubbles in veneer
 

Thanks, I'll give it a try. Does anyone know where to get Gorilla glue in the UK? Otherwise I'll use slow epoxy. I still have the foam beds for the wing so I can put the cores back in there and weight them down.

Bubbles in veneer
 

The original glue was probably contact cement. Personally, I'd be wary of trying to put that plane into the air. The entire sheet may be ready to delaminate. How hard would it be to get new cores cut and build a new wing?

Bubbles in veneer
 

I'll try to take the rest of the veneer off, if it doesn't want to come away then I'll just reattach the bubbles. If it all comes away easily then I'd rather find out about it before going any further!