I am still in the strip and prime before I start any serious body work stage. But I put some on a spot on the cab front lower, just in front of the door (small spot) and over a spot where someone had drilled an antenna hole then welded back over it. It has been there over a year and I keep checking it for shrinking etc...it still looks good. The lower I applied it there because that metal can flex a little with some pushing or bumping and I wanted to keep testing it over time, it has not cracked or lifted at the edges. I wanted to try it out and give it some abuse way ahead of time before I even came close to thinking about painting. My applications are very thin, I am not using it to build up an area. If you are needing it for thicker applications I would get a test piece of metal, dent it and apply it as you would on your vehicle and play around with it. On thick applications it is good to see if heat and cold may make it swell or shrink.
I have read lots of things on the net about it and they all seem to be good.
It goes on smooth, easy to work and sands out good and has a hard finish. When you work down to higher grades of sand paper the finish gets very similar to the metal it is on.
Being that it is not talc base it does not hold moisture, unlike bondo. If you look at old bondo repairs you always see rust starts where the bondo is in contact with the metal.
It is not a fix for holes or cracks, as always they should be repaired by welding.
Also being that it is metal always wear a mask when sanding, breathing any kind of metal dust is not good.
