Cleaning Prior to Paint or Primer

[rboltz]

I have always taken a clean cloth, soaked with enamel thinner, and wiped down the area I was going to prime or paint. I was just told by the body shop supply that you can't do that on bare body filler as it will soak in and ruin the primer. I did some research and found a large article by a guy who works for "rage" the company that made my filler. He says you must warm the area prior to priming to drive out moisture from the filler but nothing about cleaning prior to prime. Otherwise you may get a ring around the filled area. Yes, I've had those rings and did not know what caused them and am surprised the filler absorbs moisture from the air. I saw so many people cleaning with thinner over the years I wonder if it is OK now? If not thinner, how do you degrease and clean these days?

[k8icu]

Does the paint shop recommend anything? Do they have a special cleaner that will not effect the filler? How about just using a tack rag? Then again it's an army truck so just blow it off and whipe it down with a clean cotton cloth and shoot it... Any dust particles just add to the patina...

[SAC715]

We wipe down everyday with DuPont 3939 and have no problems. Just blow it off wipe the area down with cleaner and dry it off with a clean dry towel,then once it's dry tack it off before you apply your primer. I would put on an etch primer first on the bare steel then your filling primer/surfacer over that, or if you feel like going top end just put on a DTM (direct to metal) epoxy primer.

[rboltz]

We did all the welding, then plastic media blasted the dis-assembled truck. Then immediately wiped down with thinner and epoxy primed it and all the parts. I did the filler over the epoxy primer as needed. I was just wondering how to wipe down before re-priming over the filler. I did wipe and prime some spots and they look OK but the research I did says any thinner that absorbed into the filler, and did not get out, may cook out on a hot day and ruin the paint.

[SAC715]

Sounds like you know what you are doing. I think you will be just fine. I have never had a problem from wiping down the filler before priming just don't soak it to much and dry it back off. We use Marson Platinum and Rage Gold for our fillers and DuPonts 3939 is a mild lacquer and enamel cleaner. If you are still worried about it wipe it,dry it and let it set for about 30 minutes to allow it to flash off then tack it and spray away.

[sf38a1]

I always prime first,then use filler. Down here bare metal starts to rust right away,