To foam or not to foam..that is the question..

[Destroyer]

Ok, here's the situation... We have the deck off the V21 now.. The good news is the stringers are fine. The bad news is the foam is soaked... it smelled like a cesspool. Voids in the foam, gallons and gallons of water trapped... ugh!.. The PO obviously never drained the bilge and never left the access covers off so things cound dry out when stored. We're in the process of removing it all now..

So here's the question.

Do I replace the foam or not? I know it acts as a sound absorber, and also as a stiffener... but is it really necessary? We've removed the rotten balsa wood that was the underflooring of the deck and laminated on 3/4 marine ply, then sealed and glassed over the whole thing so the wood is encapsulated. The floor sits on the stringers and is plenty strong so there's no flex, so do I really need the foam? (It's rather expensive and I'm guessing that I'll need about 20 gals of the stuff to refoam).

Opinions??

[macojoe]

I never had it in my 74 V, and they did not even put it in when they made the boat.
But when I took a 10 foot wave over the bow it filled the inside up to the gunnles and still floated!!
By what i read in another thread not long ago, the 21 has some sealed areas for flotation so with that news, and what i saw with my old boat, and the $$ your going to spend i would say go with out!

That said the coast guard has said all boats from the late 70's have to have flotation in them.

[phatdaddy]

i had the deck off of my 83 & no foam, except around the fuel tank.

[awthacker]

I've removed my foam and fuel tank and am planning on using only a minimum amount of foam needed around the top edges of the new tank to keep it secured. It won't have foam underneath or around the sides. There will be 2x4s across the top of the tank, beneath the floors, just as it was originally.

[buckleyjr]

Destroyer, if it's not too much trouble, could you post some pics of your v21 with the floor off? I too have a v21 and would like to see what you are talking about. I suspect I'll have to do this someday. How'd you know you had a problem?

[Destroyer]

Originally Posted by buckleyjr

Destroyer, if it's not too much trouble, could you post some pics of your v21 with the floor off? I too have a v21 and would like to see what you are talking about. I suspect I'll have to do this someday. How'd you know you had a problem?

Pics will follow shortly...meant to post them with the original post but had a problem with the camera. I didn't know I had a problem with the foam..although I did suspect it. When I bought the boat I knew the floor was soft. Reaching in under one of the access hatches I was able to pull out small rotted wood pieces from the floor and it was soaked, so I knew I'd have to replace the floor and probably the foam.

Originally Posted by Spareparts

I stuff pool noodles in areas to act as flotation, if you can find them on sale, they are cheap and easy flotation

I've thought about that several times Spare.. Seems like a quick, cheap, easy solution...and with spring just around the corner they will be available in the stores shortly.

Originally Posted by Bgreene

Having used foam I'd say definitely yes for you to use foam for the following reasons:

1. It adds floatation - a very, very good thing in case of swamping etc right ?
2. It adds sound deadening - less hearing the water under the hull, sounds more solid.
3. You've already corrected problems, so it won't likely get soaked again.

Assuming you've used foam before, and know how to use it, you'll do a careful job to avoid the pitfalls:
1. Pouring too much in a section, then dealing with the expansion issues.
2. Avoid getting the liquild on your hull surfaces - almost nothing stains worse.
3. Mixing too much at a time.

Finally, it actually contributes to the boat's structural integrity, less flex, more firm overall when the foam is used correctly and expands to a nice tight fit into specific sections.

I hate it when people are right and it costs me more money..<sigh>.. I have to admit that you're right Greenie....for all the reasons you stated. I'm already looking on eBay for closed cell foam kits.. Still not 100% sure that I'm going to go that route.. the pool noodles that Spare suggested are a good idea. Quick, cheap and they are closed cell also.. the only problem with them is the voids that using them would leave that poured foam would fill....but otherwise they are really a great idea... gotta think it over.

Hmmmm...here's a thought...I wonder if I could use both? A kit contains enough foam for 15 board feet..(1' x 1' x 1")... I wonder if I could pour some foam around several vertical round sections of pool noodle cut to the proper height...let it set ...(1 minute)... and then repeat the process if necessary to achieve the desired height. The noodles would act as a filler, and the poured foam should act as a binder and would fill the voids. They are both closed cell foam, so there shouldn't be a compatability problem there.. Might have to try a small test in a plastic bucket first..but it sounds like a workable solution.. anyone have any thoughts?

[reelapeelin]

I can't imagine the relatively small amount of foam in the tank compartment would assist much in keeping a 21 afloat if swamped...certainly not if it's saturated...if foam at all, I'd follow Thacker's advise, but personally would find better way to secure the tank, leaving the foam out...MHO...

[phatdaddy]

aw, if you are using pt 2x4's with an aluminum tank, you will need a barrier between the wood and the tank. that was the case with the older pt , not sure about the new yella stuff.