The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Expanding Foam

Has anyone tried the expansion foam that supposedly does not push to sound deaden the A B pillars, cavity between tank and Window? I'd like to try it, but am scared.

Even thinking about the cavity between the inner and outer roof?

There are two types if you use the type used for insulating windows it does not have as much force.

Something to consider
Expanding foam products for construction come in many variations and some are open cell while other are closed cell

Both open and closed can get water logged, but closed cell takes much longer to soak in water
All foams once water logged cannot be dried out and must be cut out, my dad had a old panel van that was foam insulated and the foam didn’t stop condensation from penetrating the foam to the back side of the metal body and this lead to massive rusting out of the whole vehicle in a decade.

Since this foam would be acting like it’s own vapor barrier I would only consider a closed cell type for in a car

All the single can foam products are open cell
You need a kit that mixes two products in the nozzle to get closed cell foams
They are highly exothermic but spraying in metal you should be fine.
-s

Consider that foam may trap moisture, either from water intrusion or condensing.
If you use sound deadening pads you will get significant improvement, removing the tank to install if necessary, in the pillars will offer less result as those areas are small and tight which resonate less. Larger the span the more it resonates.
Summit has their own brand peel and stick rubber/alum pad kit that priced out well. Still have extra laying around.

When I did inside the door panels, floors, firewall, and cab rear lower half I got significant results, if I had done behind/above the headliner I would expect added reduction (is added reduction and oxymoron? How about further reduction)
The doors sound more solid than I expected when they close instead of tinny, even though I did not do the outer skin (so they could breathe).

Chuck

I don't think completely filling void is necessary. Just getting a few areas will stop the resonance I think. I am very happy with how thuddy the floor and rear is up to the top of where the tank goes. As soon as you start tapping high in the B pillar you can hear it vibrating. Same with the roof.

If a guy didn't fill it completely air could still circulate and dry if any moisture got in there.

If you're just trying to take the "ring" (like a bell) out of a panel, just about anything that can be stuck to the center of it will work. I've seen where they just took a glob of roofing tar (or something similar) and smeared it on the underside of the panel. Roofing tar probably wouldn't be the best choice.

I had mine sprayed with fluid film, inside doors, rockers, roof, window killers, everywhere he could get. Truck sounds much more solid, all tinny sounds gone, more quiet going down the road and I don't have to worry about rust starting on the inside of all my new panels.

What is fluid film in this context?

Took care of the ring, tinny sound, truck is much quieter. NO moisture issues. We use spray foam a lot in my trade, it is highly over rated.

They make a product just for this app called Lizard Skin.

Never would have guessed that fluid film would deaden sound. Would be super easy to get it in places impossible to access with other products.

Took care of the ring, tinny sound, truck is much quieter. NO moisture issues. We use spray foam a lot in my trade, it is highly over rated.[/quote]



That being said I can easily build a flex hose (spray 360) for some undercoating to be sprayed into these areas. Once bonded it would not absorb moisture?

Yes, you can buy everything needed to spray it, a small hole in the doors and a plug . In the roof area we went in thru the rearview mirror hole and sunrises holes, about a three foot hose with 360 spray. I was impressed. I don't think there is anywhere you can't get it. It is impressive stuff.

I used ABESCO fire stop expanding foam to seal the openings between the engine compartment and the rear quarter panels on my VW beetle. That was 15 years ago and there is no evidence of rust and it is an effective seal. This foam has very little water absorption and is typically used to seal around ducts and electrical conduits in fire rated walls and floors. I'm not sure I would use it to completely fill a cavity but it expands to fill a large opening similar to Great Stuff. It is not the same as Great Stuff. The two part foam would be better if you need to fill a sizable cavity but I don't know about it's flammability.

Mark

Here in northeast Pennsylvania water absorption equals rust, why I used fluid film. Unexpected benefit was sound reading in those areas, roof, doors, box sides even hood area. My guy is a professional and I am very happy with the results. It even surprised him, I think I'm the only one that would a vehicle 50 plus years old and fluid film it.