Originally Posted by bannerd

Without air.. rust cannot grow. You could take a piece of rusty metal and dip the entire thing in wax and throw it out in the woods. Said metal would last forever until the wax coating is breached. Once the coating is breached you need to remove all of it and respray.

I've used POR15 on a customers dakota. It was 5 days in prep work, sand blasting the frame, removing the bed, sand blasting that. Pressure washing, using acid etch and then applying the POR15 (one day). It lasted two years in the salt belt before the POR literally started to flake off in large chunks. POR15 tries the same concept, get the air away from the metal. Fluid film is okay, it comes off way to easy, though. Cosmoline sticks around but the wax can be breached(easy fix, spray on top of it). Wurth wax and SKS is good, I have SKS on my truck and it is still there. The issue is I don't know what is happening underneath it.

Honestly, hands down, the best rust protection is some zinc enriched spray then some paint over that. Moisture makes its way behind the paint and it bubbles. This is just a flag to wire wheel the area and treat both sides of it. It can bubble if a rock hits it and breaches the surface. Maybe the back side had a pin hole, wasn't treated and pushed it out through the paint on the other side.

Get some krud kutter rust converter, let the acid do the work and then treat with zinc and spray paint. One thing about grease, if you spray that on body panels and you run body filler or fiber glass resin on the otherside. If there is a pin hole the oil will literally go into the body filler and the paint will not stay. Been there, done that

Originally Posted by MrFusion

Definitely food for thought.

I had an idea earlier today (as I frequently remind my cousin Andy i have lots of ideas...they're not always good). When I was in High school I worked for a guy named Charlie Diamond in Bath NH. He had a small production plant that made cellulose (blow in) insulation among other things. The plant was powered by a small hydroelectric generator that dated back to around 1910. He had barrels of waterproof grease for the bearings in the penstock that were exposed to water. One day I had to move one that was open and messy. I got ZEP (i think) waterproof grease all over a pair of acid washed jeans (wicked early 90's) I was wearing. I ran the pair of jeans through 2 hot wash cycles with plenty detergent on them and ended up throwing them out b/c the grease never came out. I lived off stale donuts for part of that summer so I only threw out stuff that was truly done for.

Maybe I'll just slather the frame of the truck with waterproof grease and be done with it. It IS miserable stuff to deal with but...

Nah I'll probably try to do it right.

Originally Posted by MrFusion

Have you ever used this product on a frame that was already rusty? I did some research on it and it sort of sounds like spray on cosmoline.