Tell me about polyurethane foam.

[salty87]

Re: Tell me about polyurethane foam.

i've been on the fence but am starting to come around. i had been thinking the foam locked it all together too. but now it really seems like the foam is only needed to hold rotten decks together. i don't think i ever saw my boat with a solid deck to know the difference.

my old oem foam job had pockets on top where water collected/sat on top of the foam, voids where foam didn't penetrate, no drainage at all, and holes for pouring foam that weren't properly sealed back up.

 

[Tail_Gunner]

Re: Tell me about polyurethane foam.

Here's the manufacturing problem with 2 part foam, you don't really know until you open her up.

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I don't like foam and I don't have the answer. I like the coke bottle with sheet foam idea for sound deadning and floatation, but never used it.

It's easy to see from your pic's how water could be trapped and cause rot in a floor or stringer's. But as of todate i cannot find any mfg stating they use a good quality two part urethane foam.

What i did was to lay down the sole of the boat {both sides glassed) on top of the stringer's, the sole had vent's drilled and was cut 1/4 short on all of the surronding edge's. I had snapped a chalk line around the perimeter of the boat level with the the top of the stringer's.

With the boat level and the deck down i poured as much as two gallon's of foam at a time ( it was just one large void) i watched the foam lift and level the deck to a flat position. when the first vent hole's started venting i just capped them and went on to the second or outside vent's, you again could feel the deck lifting it's self up to the chalk line where i had a guide to prevent it form going any higher and watched the foam expand out the side's. from there just a grinder was all it took to clean up the over flow and seal her up

I doubt there are any void's, the foam was compacted by 400lbs of weight and it did lift us both up it can really expand.

There is sone side done and you can see the guide i used to prevent the floor from rising any higher than the predeterminded height. Noitce how the other side sag's there is no foam in there

There she's all done, you can see the foam in the vent's and on the outer edges of the boat it compacted and lifted 400 lbs up about 1 inch.......and ready to gind it all off.

Now she's finished all that left's is to glass up the vents and the floor.

Here's a corner where i took the grinder and cut back the foam or down, and tied the deck into the hull using peanut butter and finsihed with tape. Now she may rot in 10-20 yr's but she is already 15 yr's old and has led a good life, i hope the next will be eaiser for her.....

 

[salty87]

Re: Tell me about polyurethane foam.

tail gunner

could you explain that a little more? are you using the foam to hold your deck up?

 

[Tail_Gunner]

Re: Tell me about polyurethane foam.

In a sense yes, however the deck is laying on the center stringer's and screwed in as well. I let the foam under pressure raise the outer edge's of the deck to a predetermined postion, on the outer edge's the foam was ground down 1/2" to the bottom edge of the deck that left a 1/4" gap between the deck and those rails which is 1/2 inch wide. Fiberglass and carbisol mixed create a peanut butter like compound which is used to fill that gap, it bond's to both the deck and those side panel's you see there. From there mat is layed in all the way around the floor and glassed in.

So in affect i have deck that is screwed down to the center stringer's, and tied into to the hull with fiberglass and taped as well sitting on a bed of compacted 9lb two part closed cell urethane foam and hopefully all bonded together as one very strong unit.. I should also say i used west system's which is supposedly a better product for gluing something like this in..

And she's done.... just about done...:redface:

 

[Maj Easy 1]

Re: Tell me about polyurethane foam.

In a sense yes, however the deck is laying on the center stringer's and screwed in as well. I let the foam under pressure raise the outer edge's of the deck to a predetermined postion, on the outer edge's the foam was ground down 1/2" to the bottom edge of the deck that left a 1/4" gap between the deck and those rails which is 1/2 inch wide. Fiberglass and carbisol mixed create a peanut butter like compound which is used to fill that gap, it bond's to both the deck and those side panel's you see there. From there mat is layed in all the way around the floor and glassed in.

So in affect i have deck that is screwed down to the center stringer's, and tied into to the hull with fiberglass and taped as well sitting on a bed of compacted 9lb two part closed cell urethane foam and hopefully all bonded together as one very strong unit.. I should also say i used west system's which is supposedly a better product for gluing something like this in..

And she's done.... just about done...

Thanks for sharing!!!!

 

[turfman]

Re: Tell me about polyurethane foam.

tailgunner.

Where did you get the foam. How you did it is the way I was somewhat thinking.

turfman

 

[Tail_Gunner]

Re: Tell me about polyurethane foam.

.uscomposites.com/foam.html

 

[turfman]

Re: Tell me about polyurethane foam.

O.K. another question for you.

How many pounds do you think you used?

turfman

 

[Tail_Gunner]

Re: Tell me about polyurethane foam.

Better question, what is the length and width of your boat, and pic's with the stringer's in.......

 

[turfman]

Re: Tell me about polyurethane foam.

18' long, 6ft wide beam, and stringers are 4' high. So I'm guessing around 35ft2. I guess the real question was if the foam expanded like the label says it will.

turfman