Do I need a sealer?, Some paint help please Options

[jonferns]

Hey guys, so I primed my car about a month ago, using Dupont 2K urethane primer. I've been reading some paint threads and it seems like some use a sealer before paint, is this necessary? Do I need to sand the current primer before sealer? Also, im deciding between using a single stage acrylic or going 2-stage, for durability and cost-effectiveness, so any advice would be greatly appreciated. Thanks

[charliew]

All the above and not much bs. Sometimes a top coat because it has hot thinners or reducers will penetrate to the fillers either bondo or the primers and soften them and the outline or scratch line of the filler might lift or later shrink and show through to the top. Sometimes you can buff it out and sometimes it will look smooth and about a month later it will show up again. This can go on for a couple of years or until you cut through the top coat and get to put more on and try somemore. Sealer coats are cheap insurance. The sealer is a barrier between the filler and the top coat, to prevent all the screwing around and wasted top coat costs and additional labor. This is similiar to putting gel coat over a fg repair to stop the print through from the strands about a year later after the shrinkage.

The top coat choice will determine what sealer you will want to use. It's really better to have all the paint stuff planned before the filler ever goes on. Try to stay with the same paint mfg.

It's all about money and time I guess.