Melted foam wing.

[Tom Flynn 1]

Hi Forum readers.

I have just bought a plane with foam wings. On further inspection (removed the covering) i have found epoxy resin was not 

used to glue the leading and trailing edges on. In fact they nearly fell off, but underneath I see quite a lot of the foam has melted.

So has anyone any thoughts on how to fill these gaps and spaces. I was thinking of a light wood filler, but totally unsure.

thanks

Tom

[Bruce Collinson]

You could re-attach them using polyurethane glue, E.g. Gorilla, which could expand into the voids and secure the les and tes (no apostrophes).   With the glue foaming back into the gaps I would think it would be secure.  You will need to keep on top of the excess glue foaming out of the gaps to avoid a mess when it cures.

BTC

[Allan Bennett]

Another vote for Gorilla glue.  If you apply masking tape either side of the join line it makes it easier to remove the overspill, though it does sand down quite easily.

[Simon Chaddock]

Tom

The fact the foam has 'melted' would suggest that at some point they have been glued on with a glue which was not foam safe.

Gorilla Glue will certainly fill any gaps but you might have to be careful to avoid it expanding too much and distorting the leading or trailing edges 

[MattyB]

You could always spot fill with expanding foam, cut off the excess once it is hard then reglue the LEs...

[john stones 1 - Moderator]

Think I would be cutting it back and using balsa.

[Tom Flynn 1]

Thanks for all of your comments, having removed most of the covering now, I have a feeling I’ll be doing a bit 

Gorilla glue, and cutting away and replacing with balsa. A couple of places are really bad and replacing seems

the easiest option.

the fuselage and tail are quite well built, but the wings are poor. Obviously the guy was not a seasoned modeller.

[Rich Griff]

Was the wing joined in the middle, with what I wonder...

[Bruce Collinson]

Wing; a circular patch of glass, belt and braces?   Circular spreads the stress risers.

 

Having slept once I’m still wedded to Gorilla glue, because it ought to bond to the foam cores.   Maybe remove loose or friable foam first.   If the skinning is loose, maybe fix those first with PVA.   I would be nervous of lightweight filler because it might well not bond to the foam cores.

 

Or, ring Bill Manley (Billkits) for new wings!

 

BTC

[Tom Flynn 1]

Actually it’s a Jodel Wing, so dihedral at the tips. That’s where the problem is.