Has anyone used GreatStuff for foam?

[SwampThing]

Has anyone used that expanding spray foam insulation called GreatStuff that you can find at the local home store? I was checking it out the other day and it does seem to be almost the same stuff as the foam I just removed from under my flooring. I'm thinking it is, just in an spray can.

Pros? Cons? I was thinking about using this stuff to replace the foam I removed as a matter of connivence and ease of installation.

Any thoughts or experiences?

 

[SaltyKayak]

Re: Has anyone used GreatStuff for foam?

I have an older 14' Angler that had air pockets in the floor. There was a slight 'give' to the areas between the stringers and I decided to add foam via Greatstuff to these voids. It works just fine and I am sure there is enough foam to keep the boat afloat even if it fills with water. However, I have noticed that the foam is compressing in the areas where we walk and the support in the voids is lessening. For these areas I recommend a denser foam.

SaltyKayak

 

[dad's boat]

Re: Has anyone used GreatStuff for foam?

Ihave used that used that foam in a truck once in about two years it started to turn to dust. I guess thats why they market for houses they don't move as much as my truck. unless you live in Calif.

 

[WaterWitch2]

Re: Has anyone used GreatStuff for foam?

I had a 1972-ish Larson a few years ago that seemed to be somewhat of a double hull on the sides. It had a few spots that were slightly soft (kind of like an air pocket). I drilled a few holes the same size as the tube on the can through the outer hull and sprayed the foam in. After it dried I cleaned off the excess foam that oozed out of the holes and filled the holes with Marine Tex. I used the low expansion stuff that I believe was in the blue can so it wouldn't make any bulges in the hull but would fill the voids.

 

[new_boater]

Re: Has anyone used GreatStuff for foam?

is it a closed cell foam?

 

[sea wolf]

Re: Has anyone used GreatStuff for foam?

Not recomended for boats. The stuff will soak up water like a sponge, & is not cheap. You can buy foam board at any home improvement store, cut it to fit & it will be less expensive. For an experiment pour some water over a gob of GreatStuff after it sets up, wait a while & see what happens. That's why it's not recomended for boats.

 

[bassboy1]

Re: Has anyone used GreatStuff for foam?

It will work, and we have used it, but 2 part foam you mix is cheaper. We usually use the 2 part stuff, and use a can or two of great stuff to patch with.

 

[GatorTom]

Re: Has anyone used GreatStuff for foam?

Great stuff is closed cell foam and won't take on water (Don't believe me? Go to their website and read the MSDS). The problem with it is it deteriorates quickly and isn't resistant to gasoline. Sea Wolf is right. Use the rigid stuff.

 

[sdunt]

Re: Has anyone used GreatStuff for foam?

Great stuff is closed cell foam and won't take on water

Then please explain why the crap I pulled out of my boat, where someone had 'drilled a hose to insert the hose' was TOTALLY water logged and helped accelerate the rotting of the floor:

http://www.shareaproject.com/pages/imageDetail,p,148,i,2695,00.html

Use building foam. All expanding foams I have run across soak up water.

 

[GatorTom]

Re: Has anyone used GreatStuff for foam?

sdunt,
I was simply answering the question as to if it was closed cell foam. It definitely is not for marine applications though. Even closed cell foam made for marine applications will become waterlogged. Just do a search on here for foam and you will see many posts where people are pulling marine grade foam out that is completely waterlogged. The problem with great stuff is that it deteriorates quicker since it is not as resistant to fuel, sunlight, etc (as mentioned in my previous post!). I would only use the rigid stuff or the 2 part marine grade stuff in my floors (Make sure you leave a channel for water to get out. Foam should not be used to sturdy up a soft spot in a floor. Sounds like the previous owner of your boat went with the "cheap" route to fix their floor and used great stuff to fill a void. Now, unfortunately, you are seeing the result. Many people are tearing their foam out and not replacing it at all. This is fine as long as you are usin the boat on smaller lakes with no big waves or wakes, etc and you don't mind the boat sinking to the bottom if it takes on too much water.

 

[GatorTom]

Re: Has anyone used GreatStuff for foam?

By the way, sdunt, I forgot to mention. The restore on the boat in your share-a-project is amazing. I want a little ski boat about the same year and style as yours. You can bet that when I find the right boat, I'll be referencing your share-a-project along the way (Probably be PMing you as well with tons of questions! Hope you don't mind...)