gap sealing foam for floats/ flotation

[TwoBirds]

Hi

I'm building a pair of small floats/amas for my dingy and am considering filling them with this foam made for sealing around doors and windows on installation.

just wondering how it would work and if anyone knows about how much a can would fill, the floats are around a cubic foot each.

2B

 

[upchurchmr]

You need to find out if the foam is "closed cell".

Open cell foam just soaks up water, just like a sponge.

Most canned or two part foams are open cell.

It can work if there is a complete skin around the foam, but it is easy to puncture. You can do a better job with it if you coat the foam with epoxy - but sometimes epoxy eats/ damages certain foams. Just have to try it.

 

[ondarvr]

The canned foams are single component closed cell products, but they aren't that durable, water, or chemical resistant. So while it could work, it's not the best option for flotation.

2 part pour foam normally costs less, but you're not going to pick it up at the local hardware store

 

[TwoBirds]

thanks guys

I'll look for the 2 part pour foam, if I can't find it locally I suppose the way to test the canned foam would be to weigh a piece and then soak it for a few days and reweigh it to see if it's absorbed any water.

 

[ondarvr]

It's not so much the short term water absorption, it would probably pass that test easily, it's that the cell structure isn't very strong, so over time the normal wear and tear starts to break them down, then it absorbs water. Plus they aren't rated for oil, gas and diesel exposure, which may or may not be an issue.

In some situations these things are very important, in others not so much.

 

[upchurchmr]

Every 2 part pour foam I know about is open cell.

Check carefully.

 

[ondarvr]

Every 2 part pour foam I know about is open cell.

Check carefully.

They're rated at +- 95% closed cell

 

[TwoBirds]

haven't had any luck finding two part foam locally, I did find some canned foam meant for use in decorative fountains and streams.

I don't like motors much so gas and diesel shouldn't be a problem, the floats are made of 4mm Luan BS1088 taped with 2" 6 ounce fiberglass tape, should protect the foam from wear and tear fairly well.

2B