spray foam versus pour in foam?

I have a friend who owns his own spray foam insulation business. He was saying the spray foam is of the 2lb variety and thus more closed cell than the pour in foam. This he said would mean a better chance to shed water than the pour in foam. He was thinking that spraying a hull with about 3inches of spray foam would suffice for hull integrity.

He said his boat, a 24' FG boat weighed in excess of 9000 lbs. and he had no doubt it did not contain enough foam to keep his boat afloat should the unthinkable happen. It would probably float, he thought, but just to the point where he would be able to hold onto it if need be. Although, he has his doubts.

So, what do you guys think of using the denser foam at about a 3 inch thickness for the hull? Is that enough to do the trick? Would having it done that way be better for runoff? As to my way of thinking, the water could/would run off the top of the foam to the rear bilge area if you had the right setup? or no?

So many questions, so little time!

Re: spray foam versus pour in foam?

sabbath20 said:

So, what do you guys think of using the denser foam at about a 3 inch thickness for the hull? Is that enough to do the trick? Would having it done that way be better for runoff? As to my way of thinking, the water could/would run off the top of the foam to the rear bilge area if you had the right setup? or no?

So many questions, so little time!

Click to expand...

Nope..the water still has to check in with gravity. H20 is still going to go around/into the foam.

Best bet is to keep the water out in this respect .

YD.

Re: spray foam versus pour in foam?

Spray and pour foam are both the same, pour foam is 2 lb. just like the spray.

Check this out:

http://www.uscomposites.com/foam.html

It'll take more than 3" of foam to keep your boat afloat should your hull be breached or you get swamped.

The USC site give the floatation value for each density of foam, all you have to do is know the weight of your boat and then divide that by the floatation value and it'll give you the number of cubic feet you need.

The manufacturers fill fiberglass boats full of foam for a reason, and it's a real good one.

Re: spray foam versus pour in foam?

Like others said, there is no difference between spray and pour foam other than how fast it expands, pour foam gives you a little time before it starts to expand, you get about 10 seconds with spray foam.

Higher density foam offers less flotation, 4# foam weighs twice as much as 2# and will cost a great deal more to use because it only expands half as much. It is stiffer and stronger though.

Make sure the product your buddy has is the proper type of foam for a boat, it needs to be gas and oil resistant.

Re: spray foam versus pour in foam?

thanks for the replies gentlemen, I really appreciate it and the insight. thanks for the websight jng, I was actually needing a sight like that. very good points to ponder