I swear by epoxy sealer because it takes me so long to get to that stage. After blasting, DX330 to clean, then epoxy primer. But then due to all the dents, imperfections, etc, K36 high build primer and then Rage Gold (bondo) and then more K36. Once I have it down to 400 grit dry and everything is as it should be, epoxy sealer. Why? Because epoxy sealer heals 320 grit sandpaper. So I go with 400 to be safe. If you don't use sealer, then the proper way according to the restoration colleges all over the country is to use 600 wet, no sealer.
So, its just easier and more sensible NOT to use water EVER before the base/clear. So 400 dry and sealer is just prudent. I understand this better than most people because I had a friend who was a disciple of the colleges and used 600 wet on MY project. Things happened and two years later, I had to replace rusted out metal BECAUSE of the 600 wet! Now after learning all this, its not a question anymore, its an ANSWER! 400 dry, epoxy sealer after all the work to seal in the work, base/clear. Stick with PPG, or whatever your favorite is, but stay with the brand all the way thru, listen to people who do this for a living like on autobody101.com forums and it gives you hope. Which is a much needed commodity when you are doing all this yourself!
