Spray or pour in foam and aluminum hulls.

[Morgan J]

Recently picked up a 1956 14' Blue Star aluminum hull in great shape, nice restoration project. The foam flotation is original and in rough shape I would like to replace it with a spray in or pour in foam, told an old fishing buddy about the plan and was told by him, "he had heard that this type of flotation will corrode an aluminum hull". Question any one know if this is correct?
Thank's.......mjm

 

[Bob_VT]

Re: Spray or pour in foam and aluminum hulls.

Complete myth!

However....... If you ever have a leak or need a repair you will wish you never went with that foam.

Most people in aluminum boats use pink or blue styrofoam insulation and cut it to fit. It does NOT absorb water and works fine as flotation.

Movint to restoration section too

 

[Morgan J]

Re: Spray or pour in foam and aluminum hulls.

Thanks Bob good advice, will give it a try.

 

[Yacht Dr.]

Re: Spray or pour in foam and aluminum hulls.

Hello Morgan..

14' eh ? .. foam.. ..

Ask local ( or far ) Coast Guard if you can fill your floats with empty small 16 oz or so pepsi ( or 7-up .. mountain dew..Coke ) bottles.

If not..then fill it with what you will..its only a 14 footer m8

Not like your going on the bluewater high seas . ( cough bought it like this sir.. )

YD.

 

[halas]

Re: Spray or pour in foam and aluminum hulls.

Consider using both: Mainly construction exterior, bellow grade or basement pink insulation, maybe 1 1/2" or 2" thick sheet (1 should be enough) and about 10 cans ( under $40) of spray insulation in between to hold things together and to fill the voids. I saw those at Home Dep for under $4

 

[jcsercsa]

Re: Spray or pour in foam and aluminum hulls.

Hay

dont use the spray foam, it not made for marine use!!! John

 

[halas]

Re: Spray or pour in foam and aluminum hulls.

I recommend using the spray in expanding foam where the pink sheets are on the lower section while the aerosol foam is on the upper level where it is not going to be soaking in water.
I made my under deck flotation in such fashion (see pictures).
The expanding foam is giving support and reduce vibration while gluing the pink sheeting together.
Minimal direct contact between the hull and the sprayed in expanding insulation material.

 

[Bob_VT]

Re: Spray or pour in foam and aluminum hulls.

Well... got any Dolar Stores near you? Swimming noodles are closed cell foam and work great. Pop bottles have beed discussed here many times too

Consider this...... if you go with foam under the deck pieces are better..... they will permit water to work it's way back towards the stern. I have been working on my Starcraft (it has big pieces of styrofoam just loose.... and a vent from the closed bow directly to under the deck) and my plan is to fill in with pink board but not stick it down. I actually plan on swimming noodles under the rails and some have holes drilled in them...... yup, guess where the control cables and wires are going to be run....

The question none of us asked..... where is the flotation now? Under the decking or in the bench seat bases? There are not too many places to hide foam in an aluminum boat.

 

[wca_tim]

Re: Spray or pour in foam and aluminum hulls.

Note on swim noodles... they're typically polyurethane foam that's pretty similar in composition to the foam used in boats already... I wory about using styrofoam, it'll dissolve into nothing pretty quick with a little gasoline... or most other organic solvents that are used in paints, primers, cleaners, etc...


try putting some gas in a sytrafoam cup...

 

[Bob_VT]

Re: Spray or pour in foam and aluminum hulls.

Note on swim noodles... they're typically polyurethane foam that's pretty similar in composition to the foam used in boats already... I wory about using styrofoam, it'll dissolve into nothing pretty quick with a little gasoline... or most other organic solvents that are used in paints, primers, cleaners, etc...


try putting some gas in a sytrafoam cup...

Closed cell polyethylene foam are what swimming noodles are made of which is plastic like a sanwich baggie. Gasoline has no effect on them.

Polystyrene is styrofoam used by many boat builders od aluminum boats.

Polyurathane foam is 2 part foam.