Rust pitting repair

[Milow68]

I would not use POR15 under any kinda putty!!!
Some of the pits could be welded over (the little pits, one quick shot with the Mig, not a steady bead).
Cutting out and patch is a very good way to deal with it.
Definately sand blast!! or you will see the rust again.

Just the old .02
Brad

[JoshStratton]

POR supposedly has a putty system that is formulated to be used over the POR15. It is supposed to be pretty good....hmmmmm

I almost want to try it just to see what happens.

[JoshStratton]

I told my wife I might be making a trip to the body shop and she suggested something I had not thought of. Since I grounded the bulk of it down, she suggested using the dremmel to clean/scrape out the holes that still exist, and then fill them in. Anyone done this one? How did it work out?

[JoshStratton]

I figured I would give you all an update. I decided I would be a 'guinea pig' for the StraightLine POR15 product....after all, with every new product, someone has to be the first to try it. I will just get a new panel if this doesn't work.

So far, this is what I have done:
-Cut out part of the rusted panel and welded in a new piece
-Grind off all paint/rust
-Use Dremmel with grinding cone to 'dig' rust out of small pits
-Clean with MarineClean
-Apply MetalReady non-stop for 45 minutes
-Clean metal with water
-Apply POR15 as directed
-Wait 24 hours, sand POR15 and apply some more
-Wait 24 hours and scuff POR15 up with 300 grit sand paper
-Apply the StraightLine filler as directed and sand smooth
***This is where I am currently. I have my (hopefully) last coat (on my 3rd) of StraighLine currently drying. Tomorrow I will sand it and see how we are doing. So far, it sands very well and adheres very well...so far. We will see what happens when I spray the primer down. If it peels off of the car we can consider it a failure.

I am not that experienced with fillers, but I hear you are most likely to see your failures during the priming process. POR15 says that the StraightLine is 100% guaranteed and is the "best filler you will ever use" and it is supposedly formulated for going over POR15, so we will see how that goes.