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Hi Bob, Yes, PPG makes a great epoxy primer but it is not for filling...it is for priming bare metal and does not provide the film build necessary to fill any significant imperfections. I would recommend that after sandblasting you do, in fact, use an epoxy primer to prepare the raw metal surfaces. To fill rust pits, etc, I would use a two-part polyester putty. 3M makes it along with a couple of other manufacturers. It is really similar to "bondo" plastic filler...but is very smooth, not unlike creamy, runny, peanut butter. For the epoxy primer you will find that there are two alternatives from PPG. One is the high end product called DPLF. This is fairly expensive at around $130/gal. A more cost effective epoxy primer is PPG's OMNI MP-170 at something like half that. Both are two part systems that require a catalyst additive. Be aware that both epoxy primers have to be topcoated within a specific time window or they should be scuff-sanded and re-applied before topcoating. The DPLF has a 7 day window (as I recall) and the MP-170 has a 3 day window. I don't think you are going to get away from a lot of sanding in dealing with rust pits and similar imperfections if you want a smooth surface. 3M makes a sprayable polyester primer-filler but I have not used it. I believe it is a heavier build than conventional primer-surfacers for filling sandscratches, etc. It would not eliminate the required sanding though. Rod
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