Dtm primer question.

FM3 Dart said

Another thing that I don't has been mentioned on here regarding self etching primer.
Because self etching primer has an acid in it, you must not put polyester fillers or primers over top of it.
The acid in self etching primer reacts with polyester based products and can cause grief.
Same goes with Metal Prepping steel. Do not put polyester filler or primer on metal prepped steel, unless you have sealed it first with epoxy primer.

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That is very true. I have mentioned using Ospho to clean metal, and that it can react to any primer that also is acid based. I had a hood once, it had lots of surface rust/pitting. I DA -ed it, used a big wire cup on the right angle grinder on it, LOTS of pitting! I put a good coat of Ospho ( phosphoric acid sol), let it dry over nite next after noon I used a foam brush to apply heavy coat of Rusteolum enamel, just to what would happen. I wrinkled it places, After it was totally dry, and couple months later, tried to da it off, I could not dent it!!! Had no shine but...... the acid reacted no doubt with the enamel. It was still adhering well 2 yr later, and still DULL! but it was not rusting.
Epoxy primer is great stuff, on clean bare metal and as a sealer, I think.