Spray-in Foam

[SWalz]

I'm in the middle of a repair project on a fiberglass canoe. At both ends, the canoe is "boxed" in (see pics). Both ends were experiencing rot. Both ends also were filled with foam. It appears that the foam was blown in, as there are holes in the tip and at the transom.

Would the spray-in foam insulation that you buy to use in your house work in this situation. Or would it expand too far and possibly do damage? (I don't want to reuse as both ends were damaged..not to mention bugs)

Front:

Rear:

After removal and sanding:

Thanks!

 

[salty87]

Re: Spray-in Foam

i don't think the home stuff is closed cell...i should say i'd be surprised if it was. you'd want to go with closed cell so your hard work doesn't absorb more water later.

 

[i386]

Re: Spray-in Foam

If it matters to you... The stuff made for boats is Coast Guard approved flotation material. That's the stuff I'll be putting in my boat.

 

[ondarvr]

Re: Spray-in Foam

What do you mean by rot, is there wood inside the enclosed area?

 

[Bob_VT]

Re: Spray-in Foam

When foam gets wet and freezes it gets destroyed. Based on the shapes I see I imagine there is rotted wood in there too. I would cut it open rip out the foam and rebuild it the right way. .... new wood, foam and some epoxy resin to seal it all up.

 

[SWalz]

Re: Spray-in Foam

i386..I certainly want my boat to be CG approved. Where does one get CG approved foam? Closest big city to me is Louisville, KY, and to the best of my knowledge, I don't think there are any boat builders that might have it. Thanks!

Rot might not have been the correct term. Let's just say it was severely deteriorated. Here is a picture of the foam. The ants had a nice little colony in there. Notice all of the voids.

 

[crunch]

Re: Spray-in Foam

The stuff out of the cans is closed cell and will stick to anything... also makes a great glue if you are fabricating parts out of foam.

Coast guard approved?... who cares?... not trying to get certified anyway.

 

[Mark42]

Re: Spray-in Foam

The pray can will work fine. All you really want is for it to keep the canoe from sinking if it gets swamped. Most canoes don't have any foam at all.

A sheet of 3/4 or 1" rigid foam insulation board can be used to "box in" where you want to foam. After foaming, then glass it all over. The rigid foam board will make nice smooth surfaces for the glass work and will look really nice after being painted.

 

[i386]

Re: Spray-in Foam

i386..I certainly want my boat to be CG approved. Where does one get CG approved foam?

I'm not plugging this brand specifically, but here's an example:

http://www.marinefoam.com/handi-foam.html

And for clarity, using that foam won't make your boat USGC approved. It just that a good marine foam will have the required bouyancy properties for marine aplication. The stuff in a can may not.


For a flatwater canoe, I think this is important. If you swamp the canoe, you don't want it to sink.

For a whitewater canoe, perhaps not so important because properly outfitted it will have airbags or other flotation systems installed.

 

[SWalz]

Re: Spray-in Foam

Thanks i386 and the rest. I appreciate the suggestions.

I am having a bear of a time with the fiberglass mat. (enough to make we want to call a fiberglass shop tomorrow to get a price. What am I doing wrong? When I try to add the resin, the brush picks everything up, including the glass strands in the mat.

Tell me I've missed something! Please! :%

 

[strizzy]

Re: Spray-in Foam

ROLLER!!!! I only use a brush to "dab", "drip", or whatever you want to call it, the resin on the glass. "Paint" the surface your about to put the cloth on, then lay the cloth, and dab the resin on, and then use a roller!

A little ways down this page there are different size rollers. If you doing any glass work, you should really get at least one.

http://www.fiberglasswarehouse.com/brushes_rollers.asp

 

[crunch]

Re: Spray-in Foam

And you may be useing too hot of a mix... if it starts to "kick" while you are "working it", nothing will help.

 

[SWalz]

Re: Spray-in Foam

Well, I finally broke down and took the canoe to a fiberglass repair shop in town. First, the owner was awesome. He gave me an honest answer to the price (basically, it would cost me more that the canoe is worth) and then gave me some great tips.

First, I had a loose peice of the mat that I was working with. He told me even he would have problems working with something that thin. He sold me some that he uses. Big difference! Then he turned me onto the correct type of resin I should be using and where to pick it up in town.

And lastly, he gave me the confidence that I could do it. SO, I'm back in the game.