Spray can foam for big repairs

[EgoSmitty]

Thoughts? Products? Better ways to go about it?

[juandoe]

see here
http://www.boardlady.com/materials.htm

http://www.boardlady.com/injection.htm

http://www.boardlady.com/petersjp.htm

[loosehead]

gorrilla glue to put boards back together

[PonoBill]

Sprayfoam is too soft and doesn't sand well, if you want to use an expanding foam get some two-part expanding foam. Even then don't use it for large areas, it's heavy and it's hard to control the expansion. Also messy if you spill it somewhere. Look at my driveway sometime for an example. Looks like someone puked on it. only it's not going away anytime this millennium.

+1 on Gorilla Glue. Greatest glue around for tricky repairs.

[Ucycle]

+1 on Gorilla Glue too make sure spray a mist of water to help accelerate foam expansion. The 2 part expanding foam stick to any thing and everything so tape and tarp anything you dont want to stick on.  Also they turn yellow really fast under the sun so paint those area or finish it with microballon/epoxy to cover the expanding foam. One more thing let it cure for couple days because they out gas so it might cause premature delamnation due to trap gas if you glass early.

[EgoSmitty]

I have a pretty big repair to do. It is probably 3X5 inches and an inch deep. That would be a lot of gorilla glue.

[punasurf]

I think the idea is to glue in a chunk of foam, shape it to size, then glass.  Wouldn't use spray foam, or even the 2 part stuff.  Too much air bubbles inside.

[EgoSmitty]

I tried some West Marine two part epoxy and filler powder today and ended up melting some foam. What would you say about common construction Spackle for filler, resin and powder filler to finish, then glass and finish?

[PonoBill]

Always tricky, microballoons or other filler alters the cure of the epoxy and can result in a lot of heat. If you have a really big area and don't have the original foam you can square off the edges of the damage, glue in a big chunk of compatible foam (eps) and start shaping. There really aren't any shortcuts.

[Celeste]

Lots of different "microballoon" out there,  the common ones are phenolic, glass (.6lbs/ft^3) and light weight glass (.28lbs/ft^3).  If you have to do large repairs, seek out the lightweight balloon.  Heat in thick repairs is a problem, but can be controlled some by using slower hardener.  Still it would be prudent not to make a single "batch" thicker the 1/4".

[EgoSmitty]

Ok, so as it stands right now, I used some closely fitted foam blocks with lightweight spackle as filler. Once it dries Ill use a bit of epoxy resin with 407 microballoon fairing material from West Systems. Then glass and finish. Ill post pics of the entire ordeal once Im finished. Not bad for an amateur I guess and just in time for BOP!

[punasurf]

If it is shaped and spackled, I'd skip the microballoon epoxy mix and just glass it.

[EgoSmitty]

I thought about that. I shaped the spackle just a little shallow so I could finish with the resin then glass. If it comes down to the last minute, I may just add more spackle and glass. Thanks for all the advice, Ive considered everything.