Thanks everyone for the comments. I am a little delayed in response here due to the holidays.
Combining response to various comments above:
- Is it generally agreed that an epoxy primer is an acceptable "sealer" for this application? I've seen "sealers" available from some paint manufacturers, how does this differ from an epoxy primer or other product?
-If I am going through the trouble of adding an additional sealer/epoxy layer in this process, I would consider it just as simple to wire wheel the rusty areas to bare steel before the epoxy and avoid the trouble or "unknown" of using acid/metal prep on these areas before epoxy/primer/paint. Since there may be a slight difference in surface texture of these areas, it would probably sand easy enough with the high build primer. If not, its a firewall and not a show truck... Any thoughts to this idea?
-If I proceed with the idea above and remove the rust anyway, the issue is more paint/chemical compatibility over the OE paint. Does anyone have a negative experience with shooting epoxy/high build/ single stage urethane over OE paint that is in great shape?
