I was just thinking (and drinking) and had this wild idea that is most certianly outside the box. What if someone filled the frame with that expanding foam and then painted it with POR-15. The purpose would be to stop the rust from inside the frame and keep rocks and dirt out.

What was you drinking graemlins/beers.gif graemlins/clonk.gif

Sounds like he was drinking and maybe a little smokin too. ;)

Well, why is it a bad idea?

RUST, ALOT OF IT

ok, how is it going to rust if it can't get wet?

It doesnt really have to get "wet" ,just the dampness from a cool garage is enough to get in there and rust it out.

I would think just putting por on it and boxing it in would be better.

Originally posted by jmhardin:
ok, how is it going to rust if it can't get wet? But what about existing rust continuing to attack the metal from the inside out? Wouldnt you need to cover the inside of the frame, in it's entirety, with POR or powder, then fill and POR? Since there is bound to be rust in there somewhere you would need to get rid of it or seal it to prevent it from spreading before it was filled, no?

Maybe acid dipped, e-coated or glavanized and then filled and POR'd?

ok, lets say I por-15 it, then fill it with the expanding foam?

I guess it would be waterproof, but I don't know what kind of chemicals are in expanding foam. They might be more detrimintal to the metal than moisture. At work, we can't touch an airplane with RTV because of the acids it contains. RTV is corrosive to aluminum, according to our engineers. I don't know if there would be a similar problem with expanding foam or not.

Many posts and rockers NOW have a foam type filler in them. This not only keeps dirt, dust, sound out but also aids in strength. I dont have any 3M part numbers on me for the foam should be under a structual foam filler name,Ill do some more checking on it for ya...Eric

Edit...this is right out of my ICar repair manual
http://www.chevelles.com/showroom/foam1.jpg
A fellow member by the screen name of Crankshaft was planning on doing this all well. I believe he works for some type of OEM adhesive company that tests bonding adhesive and such try droping him a line

Na na na na na tongue.gif

The foam Eric is talking about is designed for that purpose. Going to Home Depot and getting the wall type is not. A boat I had was repaired with the wrong foam, it ABSORBED water. The type foam you need should be closed cell nonhydroscopic.

since we (or at least I!) are all talking wild, why not completely fill all of the holes i.e. "seal" the frame and fill it with oil. It would never collect any water cause we could add a recirc pump to it with a h2o filter, then we could add bigger brakes, a bigger gas tank, and 5 point harnesses to keep you in the seat as you try to turn a corner at 85 and the car wants to keep going straight!
in reality, the only way to prevent it from rusting is to have done so BEFORE it began. Who had the insight to paint, powdercoat, or otherwise EFFECTIVELY treat the inside of their frame against rust 30+ years ago. All the efforts to rust-proof cars in the midwest only added weight, cost, and the spray tended to fill and clog most of the drain holes that Detroit was so kind to provide for us, thus preventing any water from getting out, and actually adding to the problem. graemlins/clonk.gif
You might just do yourself a favor to blow dry air through the frame every once in awhile.

And I have yet to understand why the manufatcurers can't make a car body as tough as a match-box car. I can drop one from ten feet into concrete and it won't dent it! ;)

I was at the body shop yesterday and the guy was painting a plastic car. He could not find any metal to cover. Said he was using a water based primer. He said, "Hey, don't have to worry about rust do ya?". I think it was a Saturn.

Well then,why not seal the frame and use it as an extra gas tank ;)

It would also be a good place to hide the NOS.

Originally posted by jmhardin:
I was at the body shop yesterday and the guy was painting a plastic car. He could not find any metal to cover. Said he was using a water based primer. He said, "Hey, don't have to worry about rust do ya?". I think it was a Saturn. Did he sand down those little tabs where the body parts were attached to the little tree? :D

I'd settle for paint that was that good!

I am thinkin about having my frame galvanized. I know there was a guy here that did it. just think it would be coated on every concievable surface. it would not rust.

hey, that was me! so far so good.
http://members.aol.com/smartasreality/page04.html

http://www.chevelles.com/showroom/framegal-07.jpg

I had the floor and frame of my 29 foot inclosed trailer sprayed with 4-5 inches of inslation foam. It helped block temperature and sound, It also rotted the frame work underneath the floor. :rolleyes:

Structural foam is a great idea!

We deal with structural foam for the OEM's at work. These foams are isocyanate based urethanes. You NEED to have the inside of any panel e-coated, otherwise it will not stick, and you will NOT get the strength benefit.

The new Ford GT (based off of the old GT40) has a bunch of our foam (24 lb. density) in it, as well as multiple car platforms from the big three.

These foams are hard as rock, so do not get confused between the typical "foam in a can" and this stuff; we are talking worlds of difference.

Foam WILL NOT STOP rust, since it not bonding to bare metal! These areas MUST be treated first.

I am in process of modifying my own frame, and one of the things will be foam in the rails; they will be coated inside before we apply it.

Crankshaft