floatation foam

[Lew Morris]

looking for pourable flotation foam materials and technique.

Currently using a 1:1 kit from an outfit in So. Calif. named RevChem.

This material comes in 2 one-gal. cans and combines within twenty seconds and starts to expand within another 10 -- no dispensing equip. required. Half a "dixie cup" (of A+B) yields a 3# coffee can volume of foam.

Doesn't do well when poured in deep sections -- its own weight seems to inhinit expansion

The material is okay... but there is probably something better...

Any suggestions...

thanks,

Lew

pour it in sections, not all at once

[orgdonor]

Hello everyone! After reading these forums and taking the advice of others for so long I feel I can finally contribute something. I have a 1986 Boatel houseboat which my wife and I purchased from Lake Powell a couple of years ago. We had the boat moved to a lake in New Mexico and have done a few things to make it ours. But of course with these older pontoon boats they leaked. I used to go out and pump the chambers every so often until one night a storm came through and filled up 3 of the chambers completely. We had the boat in Dry dock for a while and had just about given up trying to fix it until another post came up about this Houston based company called Tailored Spaces.

At first we had a welder fix what he could but as with steel it was creating more weak spots and cracks. I finally called these people only to find out they service our lake 4 to 5 times a year. Now with all the discussions on the web about foam in a pontoon I am now loving this stuff. The cost of $ 3300.00 to fill all the boat was a little hard to chew but I was amazed at this stuff. It turns out that it is what they call a closed-cell foam that was designed by the Coast Guard and is used for them on a boat called a cutter. The owner of the company we had install it was very knowledgeable and said most of his business is Coast Guard stuff but has a route through various states when they are slow. Pretty amazing stuff though he first used a fiber optic camera to check the inside for problems before pumping and then used a strange gun to pump the foam in at around 400 degrees (it cured to the touch in less than 2 minutes). According to the company it doesn't add buoyancy but it did on our boat because it reshaped the pontoons to their original factory specs. It even popped a huge ding out of one that was their when we bought it. A year later were still floating higher than ever. I see him a few times a year at our lake pumping boats.

What a world of difference. He was able to expose cracks in the pontoons we didn't even know we had. I didn't even have them fixed. The pontoons are smack full of this stuff on the water for a year and no problems. They said it adds 3# for every 11 cuft. It didn't even budge our boat. I also read on the Coast Guard site after I had it done that it has something in it that prevents rust. And the best part it's a green friendly product. I found them thru their website at TailoredSpacesofTexas.com.

Happy Boating!

[rasorinc]

Hi, I use stryofoam billets on the boats I've build. can get them in any size I want and at a good price. I've had them under a floating dock for 35 years - still in perfect shape except for a few muskrat bites. NEVER absorb any water
and are compatable with epoxies

[marshmat]

The extruded polystyrene (XPS) billets rasorinc is talking about are a great choice for docks. XPS is probably the most waterproof of the rigid foams. I don't think I've ever seen the expanded (EPS) variety as permanent flotation, although in theory it could be done. (The much higher porosity would be a problem if in contact with water).

A lot of the pour-in-place ones are polyurethane-based. Great for filling inaccessible compartments in fibreglass or plywood boats to meet the level-flotation requirements. So far I haven't encountered any self-expanding PU foams that hold up against constant exposure to bilge water though- they do deteriorate and soak up water over time. And not for use in aluminum boats- they'll encourage corrosion.

The expanding foam orgdonor mentions- I'm not sure of its chemistry. It is amazing stuff though- I have seen pontoon barges that everyone had given up for dead years ago brought back to life with this stuff. The incredible pressure it can create may be a problem in some applications. (Although it is a benefit in others- there are urethane-based systems similar to this that can be used to jack up and level entire buildings, where the subgrade has compacted or washed out after construction.)

[BigCat]

You can also get closed cell polyurethane floatation foam that is fire retardant from Composites One. The USCG specifies 2 pound per cubic foot density for floatation foam, so every ton of floatation (long ton,) weighs 70 pounds. PU can be foamed in place by anyone. Styrofoam is available only as a finished product.