Would "Great Stuff" Foam work for this....?

[Captgps]

What about Injectadeck> I havent used it but watched video on use.
Two canisters mix in the gun, epoxy expanding foam which is applied through small holes.

[john61ct]

Not epoxy, also polyurethane, likely similar stuff to what I posted, maybe doped to be hydrophilic while setting.

Their real added value is the injection "syringe", and the hard part's locating and getting into all the voids.

Won't stop further rotting, not a real substitute for the proper major $urgery.

But maybe a cheap way to get a few more years.

[SeaSon]

For the record of future searchees:. The Great Stuff is open cell foam, so it will allow moisture to penetrate, and on thinner decks may cause a bulge in the deck as it expands.
I know.

Supposedly some higher quality foams are closed cell, but I never tried those.

[john61ct]

Dow tech support says rated 80% closed cell.

[SeaSon]

Originally Posted by john61ct

Dow tech support says rated 80% closed cell.

So only 20 pct of the water gets through to re-wet the core?

[leftbrainstuff]

Originally Posted by OldManMirage

Ok, here's the situation. I'm slowly working may way around different deck fittings and pulling/cleaning/rebidding them as needed. Came across the Deck Waste fitting as I'm also re-doing the head hoses and such.

There is a void. I have a Cape Dory with balsa cored decks and it looks like there was some rot that someone may have dug out but did NOT fill back with anything. The decks are built thick but I had noticed this spot was a little soft and now I know why.

I can reach in with a stiff wire and find what feels like "good" balsa, i.e., not soft or crumbly. It's not a large area, maybe the size of my hand.

So my question is - would the "Foam in a Can" stuff be ok ? Or would you mix up some thickened epoxy ? I feel like the foam will do a better job of filling the space, but would not be as strong as epoxy of course. But then again, neither was the balsa !

Opinions please ?

If you squirt it into a cavity it will typically expqnd and split or delaminate the coid tou're trting to fix.

Use thickened epoxy or epoxy and flock, micro balloon or glass fibers.

[Tellie]

Originally Posted by rosatte

Hey I got a Ted Johnson 4 horse bought it about 45 yrs ago at Sears still works great

Ted Williams? Had a 5hp air cooled one on my first power boat. 12 year old kid, a 12 foot Sears boat and Saturday adventures. No registration, no safety equipment. A milk jug full of KoolAid and a bag full of P&Js and explored the Keys all summer long. Not a water cop in sight.

[JC Reefer]

Originally Posted by john61ct

That's what I thought! This stuff

​ http://www.uscomposites.com/foam.html

comes in up to 16lb per cu ft, should be much tougher that e.g. divinycell

What say you hive mind? Given caveats above, need practice first, can really make a mess if you pour/inject too much.

I think have worked with this stuff in the past for a fridge installation on a Morgan. When mixed, for the first few seconds it is about as fluid as water but then It expands at a much faster rate than great stuff.

With the fridge the fluid first crept out through any openings in the frame. Then expanded so fast that the entire structure started to explode.

At 15 I made a heck of a mess. And boy does it stick. I was eventually able to sort it all out but never again.

[john61ct]

Originally Posted by SeaSon

So only 20 pct of the water gets through to re-wet the core?

Not saying it's suitable for that job, just correcting misinformation. In my experience completely impervious to moisture from splashing, humidity etc.

All the closed cell expanding foams are a percentage, not 100%.

Loctite's is apparently a bit better.

[john61ct]

Originally Posted by JC Reefer

I think have worked with this stuff in the past for a fridge installation on a Morgan. When mixed, for the first few seconds it is about as fluid as water but then It expands at a much faster rate than great stuff.

With the fridge the fluid first crept out through any openings in the frame. Then expanded so fast that the entire structure started to explode.

At 15 I made a heck of a mess. And boy does it stick. I was eventually able to sort it all out but never again.

Yes, all true for any, no your expansion proportions at that temp and measure accurately. Easy to do in stages, layers.

Will explode a closed mold, always give escape routes.

And thoroughly mask, nothing cleans it up after it dries but mechanical removal.