Non water absorbant expanding foam?

So that's what I am looking for, is there anything out there that fits my needs, I have a beater that needs some holes filled in but unlike "Great Stuff" I am looking for something that wont attract water. Any ideas? Thanks

Hurricane adhesive foam is closed cell and cures quite a bit harder than "Great Stuff." I worked on a trailer rig that applied it here in Florida, but I think there's a roofing foam available in a can. Maybe try a roofing supply house, or else chase down a foam trailer and offer the guys a little cash to spray your car!

Check at marine supply stores.

Pourable or sprayable?

Google "marine expanding foam"

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

On the subject of foam, many years back SCC had a 300ZX project they were working on. In one of the articles on the chassis they filled the "frame" rails with some type of expanding foam to stiffen the chasis. This was when Dave Coleman was there, so I doubt someone with his knowledge would do such a thing if it was a bad idea. Anyone ever try this or have experience with the idea?

Thanks guys, exactly what I was looking for! And preferably sprayable.

bigbrainonbrad wrote: On the subject of foam, many years back SCC had a 300ZX project they were working on. In one of the articles on the chassis they filled the "frame" rails with some type of expanding foam to stiffen the chasis. This was when Dave Coleman was there, so I doubt someone with his knowledge would do such a thing if it was a bad idea. Anyone ever try this or have experience with the idea?

iirc, it was a 240, and they measured body flex by jacking up one front corner and measuring how high it lifted the rear either rocker or tire, then did the foam thing, then did it again. i think they found that it flexed something like 20% less with the foam. dunno what kind they used though : /

BTDT..

The foam works nice in rockers and unibody framerails, it does stiffen the chassis a bit.

I helped my buddy out with his mini-stock Tercel one year.

We poured the two-part expanding foam into the rockers and rear quarters of his car.

You could beat on the sheetmetal with a hammer and hardly leave a dent. The car held up really well but eventually the tech inspectors caught on.

The foam comes as a liquid in two parts, mix together as per instructions. Pour in through a hole made with a hole saw. Work fast since you only get about 5 minutes before it starts expanding.

Shawn

structural foam is what Dave Coleman used.. I am intending on using it in my fiat

Where do you get the structural foam? Is it at Homedepot? I remember reading about it and considered researching and using on my last project but dissmissed it as to much a pita to find.

We got ours from a local plastics supplier, Industrial Plastics IIRC.

Shawn

porksboy wrote: Where do you get the structural foam? Is it at Homedepot? I remember reading about it and considered researching and using on my last project but dissmissed it as to much a pita to find.

This is where I get my foam and urethane. Its a two part polyurethane foam that is available in a bunch of different densities. Not the crap in a can.

US Composites

The two part seat foam is available from Pegasus, RPW, among others. It's less than $40 for enough to do a seat.

Just be careful with the stuff. When it expands it exerts a fair amount of force. Spread over a large panel it can be hundreds of pounds, enough to bend things.

8lb./ft^3 polyurethane 2 part marine foam is crazy strong. I used it for the impact attenuator for out FSAE car. kb58 is right about the expansion concern, it's like 8:1 expansion and it sets up really fast.

bigbrainonbrad wrote: On the subject of foam, many years back SCC had a 300ZX project they were working on. In one of the articles on the chassis they filled the "frame" rails with some type of expanding foam to stiffen the chasis. This was when Dave Coleman was there, so I doubt someone with his knowledge would do such a thing if it was a bad idea. Anyone ever try this or have experience with the idea?

Oh, I do miss Dave. For that matter I miss SCC. I now have a sub to Modified. I'm giving them a chance, but I doubt I'll be renewing. Damn, this economy anyway. 'Course SCC was having budget problems anyway. I have that issue floating around somewhere, but not sure which one it is in. Anyway, I'm off topic. Sorry.

http://www.sr20forum.com/members-rides/245943-93-classic-restoration.html

Here is exactly what you are looking for. Detailed info about using foam.

http://foamseal.org/auto_after_ordering.htm here ya go, I've been wondering about this stuff for years, Acher racing used something like this in the late 80s on thier road racing jeeps.

Alfa used it on the Alfasud as well. Those cars would rust at a visible rate, and I've heard the foam blamed for that.

I was looking into a structural foam for chassis reinforcement, but chickened out.

There are a couple of problems; Corrosion can come not only from absorbing moisture in the foam, but from plugging the drain channels in the chassis and trapping moisture that comes into the car after the foam is applied. Also, long-term durability is questionable. I've seen structural foams turn to dust in high-vibration industrial applications. Dust is not stiff.

The potential for corrosion stopped me from using it, but it might be good for something with a short projected lifespan, like a Challenge car or LeMons rig. Someday I'll try it just to say I've done it.

Here is the link to SCC: http://www.modified.com/projectcars/0006scc_project_nissan_300zx_part_5/index.html