Expanding foam

[prv]

Not the two-part kind that bursts canoes, but the builder's stuff in cans. I know it's not suitable for long-term use on boats, as it soaks up water, but does the panel think a can of it would be of any value for emergency hull / coachroof window / etc repairs? I mean the kind of situation where you're nailing bunk boards over holes - seems like some foam to squirt into the remaining gaps would be handy, but not if the stuff doesn't stick to wet surfaces, or doesn't foam in contact with salt, or takes 24 hours to harden, or whatever. Anyone know?

I have a can on the shelf in the shed with no other purpose, that's all, and a big bag of bodging and repairing stuff being assembled.

Cheers,

Pete

 

[oldharry]

Not the two-part kind that bursts canoes, but the builder's stuff in cans. I know it's not suitable for long-term use on boats, as it soaks up water, but does the panel think a can of it would be of any value for emergency hull / coachroof window / etc repairs? I mean the kind of situation where you're nailing bunk boards over holes - seems like some foam to squirt into the remaining gaps would be handy, but not if the stuff doesn't stick to wet surfaces, or doesn't foam in contact with salt, or takes 24 hours to harden, or whatever. Anyone know?

I have a can on the shelf in the shed with no other purpose, that's all, and a big bag of bodging and repairing stuff being assembled.

Cheers,

Pete

Its orrible stuff to get off . I woulnt use it for a temporary bodge the residue is toopermanent!

Incidentally the 'fireproof foam' sold by Screwfix is closed cell,so does not soak up water, and is useabe as a cavity filler if you can stand the bright pink colour!

 

[pete]

From memory it only has a limited shelf life. I took several cans back to the builders merchants as the foam would not come out of the can.

 

[nigelmercier]

I once found a can of this I had left on the boat, the bottom was almost rusted through!

 

[prv]

Its orrible stuff to get off . I woulnt use it for a temporary bodge the residue is toopermanent!

Letting the boat sink is considerably more permanent than any residue! To be clear, we're not talking about "ooh, there's a bit of a deck leak over my berth", we're talking "****, that last wave stove in the windows!" or "it's over the bunks and still rising!"

I've done the latter, albeit in a situation where a softwood bung fitted into a neat round hole rather than having to seal a jagged gash, and I can assure you that the later removal of sticky residue would not be a topic uppermost in my mind

Pete

 

[TradewindSailor]

If you're trying to fill a hole in an emergency, you're better off stuffing a rag in the hole .... preferably from the outside.

I can't see a practical use for that foam on a boat. If you use it as a filler in an emergency, the water will push it out before its set. You might stand a little bit of hope if you stuff a tough plastic bag in the hole and fill that with foam .... but then stuffing the same bag with rags, towels, scatter cushions will certainly be much better. Also stretching a tarp over the outside might offer significant protection ..... it just depends on the hole and where it is.

I quite like the idea of using an open cell foam sponge and soaking that in fast setting underwater epoxy ..... and stuffing that in the hole ..... but I've never tried it.

I did stuff some kitchen towel into a hole in the bottom of my deflateable dinghy once .... it held for over a week!

Of course the other side of the equation is to have some large bilge pumps.

 

[oldharry]

Does it set fast enough to be any use in that situation?

 

[michael_w]

IIRC there was a case of a Moody losing part of her transom against a quay in the middle of nowhere. They stuffed the hole with squirty foam and sailed off till they could effect repairs.

I had a couple of cans on board for my Atlantic Circuit.

 

[prv]

Does it set fast enough to be any use in that situation?

That's exactly what I was asking

Pete

 

[prv]

You might stand a little bit of hope if you stuff a tough plastic bag in the hole and fill that with foam

Now that one I know doesn't work

I tried to use a similar technique to help wedge Kindred Spirit's new fuel tank in place. I thought I could put a tough rubble-sack in the space, squirt in foam, and have it set into a solid block with a plastic outer skin (the sack) that exactly filled the space but wasn't glued to anything. Turns out the stuff needs air to set, and if you squirt it into a bag it never goes off, after a while the foam collapses, and you just have some nasty liquid smeared on the inside of a flat bag.

Pete

 

[gordmac]

Racing car seats are made by putting expanding foam in a plastic bag with the driver sitting on it, two pack foam though.

 

[Seatrout]

The only practical use of expanding foam is to silence an intruder alarm bell/siren prior to a housebreaking. If you are not a housebreaker, you have no use for the stuff!

 

[prv]

Racing car seats are made by putting expanding foam in a plastic bag with the driver sitting on it, two pack foam though.

I remember reading that aged about eight - it's probably where my brain dredged up the idea for the fuel tank . Different type of foam, though, as you say.

Pete

 

[prv]

The only practical use of expanding foam is to silence an intruder alarm bell/siren prior to a housebreaking. If you are not a housebreaker, you have no use for the stuff!

It did very nicely for insulating my shed roof.

(Not 100% spray foam, just filling the gaps between polystyrene panels.)

Pete

 

[Billjratt]

Well, it saved our boat from sinking after a hole was punched in the bottom of the long keel during a grounding.
We foamed the hole then tied a plank on the outside while it was setting.( having beached for a tide) The temporary repair took a knot off the boatspeed though!
I now keep a skooshy can of it aboard just in case...