What glue for Carbon Spars in foam (EPS?) wing

[Alan Thorpe]

Hey there,

I put two carbon spars into the wing of freewing Hellcat and just have them dry fitted. Trying to decide whether to use Epoxy, Gorilla Glue or Foam Glue?

I think the foam is EPS foam, is Gorilla glue ok to use with this, it says it's foam friendly, but not sure if that means all foam?

Thanks very much in advance and apologies for all the questions!

Cheers,
Alan

[kc]

If you click on the Video start arrow ( bottom of page)  here it shows Super Phatic in use for carbon spars.. Seems a good idea but I have not used it yet myself.

Edited By kc on 03/08/2016 11:16:23

[Colin Bernard]

I generally simply run thin foam friendly CA along the top of the spar so it wicks down the sides. Seems to do the job OK in my HK Vampire

[Former Member]

[This posting has been removed]

[The Wright Stuff]

Posted by Steve J on 03/08/2016 13:33:46:

I would expect Gorilla to give you the strongest join, but it can be a bit messy, so in this case, I would probably use a 30 minute epoxy.

Steve

+1 for 30 min epoxy.

It goes where you want it; stays where you put it; time to remove if you overdo it; and you know exactly where you are with it!

[Alan Thorpe]

Great stuff lads, thanks a million for the replies, that's great.

30 min epoxy, it is so!!

Sound stuff!

[Ian Jones]

What's the drying time for Super Phatic?

[Kevin Wilson]

I have used UHU POR, polyurethane (gorilla) and epoxy for carbon spars.
All worked but the Gorilla was easy and fairly clean. I glued the slot, dropped the spar in, scrapped off the excess and topped it with a line of masking tape to stop the glue foaming everywhere.
Epoxy always feels a bit heavy, but probably just my perception as I haven't weighed any of them.

[The Wright Stuff]

Posted by Kevin Wilson on 05/08/2016 10:17:23:
the Gorilla was easy and fairly clean. I glued the slot, dropped the spar in, scrapped off the excess and topped it with a line of masking tape to stop the glue foaming everywhere.

I have nowhere near enough self-discipline to be let loose with Gorilla glue. Every single time I make a mental note to use less next time - and do I ever learn?

[Erfolg]

I wonder if it is necessary to glue a CF spar into a foam wing,

I have Uhu Pored CF strip onto EPS, as in indoor models. It works.

I do not think I have glued a CF tube into a EPO wing.

I have glued a Ply spar into EPO wing using ordinary PVA , which works, although on crashing it is apparent that any strength comes from an interference type fit primarily.

I do use Polyurethane adhesive, although not a general fan. I do use it on Depron sheet to sheet. Where I wet one surface, stand on edge to drain. Apply a thin film to the other sheet, scrape of.spread the glue to an non existent film. Bring them together then weigh down with a plywood sheet with about 50 kg of lead. It weighs an awful lot, makes a mess, expands like mad. Above all makes my hands grimy, which i pick at to my frustration. It does appear that the strength of the joint is nowhere near the strength of other glues where the substrate more often than not fails. A poor unclamped joint results in a very weak joint, being more void than glue. Which reminds me i must buy some more.

[onetenor]

pu glues in general are not as strong as super phatic but Gorilla Glues is one better used right . Do not forget the water

[Alan Thorpe]

Thanks again Lads,

Think I managed to install the spar ok, one top surface of wing and one below, epoxy worked grand, just have 2 hour stuff, so plenty of time to set! Hope to fly it this evening and all going well, will stick up a few pictures sure.

Thanks a lot,
Alan