Originally Posted By: AMC
I am testing some of these rust proofing products right now so I thought I would bring this topic back from the dead.
I treated the truck in my sig with CorrosionX Heavy Duty and I like it alot. It is thick and durable, dries to a waxy/slimy film and only collects a small amount of dirt which rinses out of the coating easily. The downside to it is that it is very expensive, $100+ for 1 gallon.
I then bought some Fluid Film and treated the car in my sig with that. It is a versatile product, Very affordable ($40 a gallon) and it seems to have alot of uses but I am not so sure it makes a good undercoating. It never dries, stays on as a thick oil, collects alot of dirt/junk and easily rinses off the undercarriage in the high wash areas. If you were to use fluid film anywhere in the rust belt, you would have to apply it at least twice a year to keep coverage on the undercarriage.
I plan on trying Amsoil HDMP next, it seems like a durable wax style coating which hopefully will collect less dirt and last longer than Fluid film while being less expensive than corrosion X HD. If anyone here has experience with Amsoil HDMP, please share your findings. Stay tuned for updates!
Good info, please keep us updated.
As far as the Amsoil product, I used it on my Jeep and it appears to be holding up well. It does collect dirt, as expected, but nothing crazy. I check it and touch it up at each tire rotation.