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So my 2001 F250 just started to show signs of the infamous wheel well cancer. In an effort to stop it, I removed the inner wheel well and discovered some type of factory applied foam in-between the two panels. I'm going to treat the metal and try to reverse/seal/stop the rust and hopefully save the bed. But, the foam is still on the other side. My thought was, find something that will dissolve the foam, allowing me to clean and treat the area before the rust has a chance to start without cutting the panel out, as I had to do on the other side. I've tried Brake Cleaner and Acetone to no avail. Do any of you guys have any suggestions what might actually work? Last pic is the stupid foam. Help me save my truck.
The problem with heat is I don't want to damage the paint. I'm afraid to get it hot enough to melt, it would burn the paint. And I can't get to the foam without cutting it apart like in the pic, which I'm trying to avoid on the other side.
I guess I should clarify. I want something to pour between the two surfaces to dissolve the foam so I don't have to cut it apart. I have no access to the area unless I cut it apart.
Whether you dissolve the foam or destroy it with abrasion. It'd probably be a good idea to wear a respirator when doing that.
I have no way to gain access for a wire wheel unless I cut the inner panel out, which is what I'm desperately trying to avoid. There has to be some chemical that will dissolve this foam without damaging the metal.
I have no way to gain access for a wire wheel unless I cut the inner panel out, which is what I'm desperately trying to avoid. There has to be some chemical that will dissolve this foam without damaging the metal.
Maybe call the body shop at a Ford dealer and ask what they use to clean off the foam.
Maybe call the body shop at a Ford dealer and ask what they use to clean off the foam.
I can try but I would think if they were removing the foam, they would have the panels separated. In that case, like I did, the foam just pulls right off with minimal help from a scraper.
That is a possibility. Tonight I soaked my test piece in paint thinner. While it didn't dissolve it, it did seem to break it down to where high pressure water or air might blast it out. This weekend I will try to soak with thinner, dig out what I can and wash or blow out the rest. Fingers crossed!
I don’t know of anything that would dissolve the foam and not damage the paint.
The best advice I can offer is to spray as much internal panel corrosion prevention spray in there as you possibly can, enough that it’s dripping out of the drain holes. Repeat the application on an annual basis.
If you live in the rust belt, the sound deadener will eventually welcome the dreaded tin worms. When I first bought my truck, I sprayed several cans of 3M panel protector in the rockers, cab corners, and the wheel houses. I’m guessing that’s the only reason it took 15 years for rust to start bubbling.
Paint thinner for the win. Soaked yesterday with paint thinner in a squirt bottle. Today I came back and started digging with a long wire with a hook on the end. The stuff just crumbled apart! I was even able to blow chunks of it out with the air hose. Granted, I didn't get it all, but tomorrow plan to get more thinner ( I used all I had) and soak with more applications then continue to dig and blow it all out. I even thought of getting fishing line, spanning the entire top, and having someone on both sides to "saw" the rest of the foam out. Not complete but major progress in an effort to save my bed. Btw, the stuff on the ground is the foam, not dirt.
Is the rust at the back of the cab in front of the bed? If so, you'll probably have to lift the bed to fix it right.
If there's rust that needs to be treated it needs to be ground off or cut out. Once you remove the rust you should have access to that foam, right? 🤔
As of now, there is no rust on this side and I want to keep it that way by removing the foam from the wheel well that holds moisture, as seen in the last few pics.
I realize this isn't a Ford forum and I was just seeking advice on removing the foam, since a lot of guys here do a lot of body work and I thought it might help someone else. But feel free to delete this thread if it is deemed inappropriate.
The thread isn't inappropriate, I just think we aren't communicating the problem adequately. If there's rust in the wheel well it's either on the outside or inside of the fender. Grind out the rust either in the bed, or from the outside fender. Then you should have access to any foam that's sprayed inside the wheel well.
You can always post here. There's probably already a thread on fixing your problem. I go by the same username there but I frequent the 6.9l/7.3l DI forum and Bullnose years forum.
The thread isn't inappropriate, I just think we aren't communicating the problem adequately. If there's rust in the wheel well it's either on the outside or inside of the fender. Grind out the rust either in the bed, or from the outside fender. Then you should have access to any foam that's sprayed inside the wheel well.
You can always post here. There's probably already a thread on fixing your problem. I go by the same username there but I frequent the 6.9l/7.3l DI forum and Bullnose years forum.
I've got one going there too, a pretty lengthy one. I asked here, there and I think the G8 forum with zero results on how to dissolve that foam. I'm just trying to give back and possibly help somebody out.
FWIW - I would at this point thoroughly flush the seam with solvent to wash out & neutralize the stripper.
I would then pour POR15 or equivalent (NOT rust converter) into the seam. Literally, put POR into a Dixie cup, reach up as best you can (gloved, tyvek or arm wrapped in plastic wrap, trash bag, etc) to twelve o’clock and pour it into the seam, getting it to run both fore & aft. Obviously with arrangements to catch the runoff. Then take a 1” chip brush (acid brush, acid brush “array” or similar) and brush up & out of the seam onto the adjacent wheelhouse & back of bedside. Wait a day or two and treat with a wax rust inhibitor, cosmoline or even lanolin product (Wool Wax, Fluid Film, etc), I would not use a rubberized or asphalt based undercoating.
That will give you a great chance to prevent further rust and repel moisture. That’s the way we did it AFTER people had to pay us to repair their trucks, some just 5 years old but out of corrosion warranty. In 30 years, never had a comeback. While you’re at it, consider doing fenders (from 12:00 to rear bottom), doors, rockers & cab corners similarly but there will be no foam to deal with, even though it exists in rockers & possibly cab corners, it is practically inaccessible.
Get dirty & good luck! Pro Tip - POR style paint can be removed from skin by rubbing vegetable oil on it & sealing with plastic wrap for an hour or two.
If you can get the foam out of there I would suggest one of these two products.
Zip-Chem....Products
First choice is CorBan-22 which is a penetrating water displacing self sealing film commonly used in aviation air frames. It is available in an aerosol can. Manufacturer states it prevents further corrosion and neutralizes existing corrosion. It is not cheap, but may keep you from separating the pieces (if you can get the foam out). Note this is for dissimilar metals, but I don't know why it would not work for same materials. https://zipchem.com/produit/cor-ban-22/
Non Zip Chem choice would be 3M Cavity wax. It will seal up the joint, preventing water intrusion. But it may only stop existing corrosion if it seals the air out.
Thank you guys for the input. Had to put this on the back burner because the factory plastic intake decided to let go in the coolant passage. $800 and a few days I wasn't planning on. I'm on vacation in a couple weeks and getting this squared away before it gets cold is on the top of my list of things to do.
