Foam

SBD · #1 04-12-2011, 02:34 PM

What density of foam is used for foam installation of a fuel tank.

I am aware of all of the pros/cons of foam, just trying to figure out what type is used for this job.

Thanks!

dbiscayne · #2 04-12-2011, 04:00 PM

i've poured both 2 & 4 lb/cf foam and the foam I pulled out of my boat around the tank sure felt like 2 lb/cf.

wtenglish · #3 04-12-2011, 04:53 PM

I believe 4lb is what was recommended to me by the supplier.

GodsReel · #4 04-12-2011, 09:39 PM

does your tank have flanges on it? why foam? if you do foam, put a thin layer of pvc board between the foam and tank so no moisture can transfer.
just my 2 cents.

pelican · #5 04-12-2011, 10:38 PM

if,you properly chemically etch primed the aluminum,and coated it in interprotect,the proper thickness-10mils,then,aluminum is completley isolated from any and all moisture contact - no need for a barrier between the tank and the foam...

Old'sCool · #6 04-13-2011, 10:14 AM

Why add foam in the first place?

SBD · #7 04-13-2011, 10:40 AM

The foam debate will rage on forever. My old tank was foamed in for 34 years and it would still be going if the baffles hadn't broke. The guy that built my boat still does it the same way. I will be dead in 34 years, my new tank will likely be fine.

Old'sCool · #8 04-13-2011, 05:23 PM

I understand all that but, what's the real advantage? If properly mounted and coated why add foam? Or anything else? I'm in the middle of resto on my 23' and have elected to not foam it at all.

Blue_Heron · #9 04-13-2011, 07:08 PM

Quote:

I'm in the middle of resto on my 23' and have elected to not foam it at all.

I won't have any flotation foam in my 25 Seafari either. But I will have three bilge pumps with a combined capacity of 4800 GPH and a high water alarm buzzer tied to the float switch on the second backup pump.

As for foamed in tanks, been there, done that on crevice corrosion. For an untreated foamed in aluminum tank, failure may take a while, but I think it's inevitable.
Dave

Wildman · #10 04-13-2011, 07:21 PM

I smeared mine with coal tar epoxy and will be screwing them in, with NO foam. I also plan to leave an inch or so between them. I am hoping that as the condensation builds up on the outside the air flow will allow them to breath a little bit.