The Stovebolt Site Forums The Shop Area Paint and Body Shop Wet Sanding vs dry

I'm looking for opinions on this one. I am getting my truck already for paint at a local garage and I have been doing most of the prep work. The guy at the garage says to never wet sand on bondo or primer as he swears it will retain some moisture and cause problems later on. He says he's had customers come back complaining about tiny little spots in the paint 6 months later. The guy has been painting for 20 -odd years so I guess he knows something. Has anybody heard this before?

well I'm no expert, but I'd never get bondo wet, or surfacer primer, they are porous, as he sez - I think the primer-sealer is the wet sanded coat, as it doesn't absorb the water, and that's the coat you want real smooth anyway - I've always just sanded the surfacer up to 400 at most, my paint guy takes it from there w/ the sealer at 600 and finer, depending on how great a job you want - at times they might wet sand the color coat before a clear coat too - I did have a paint job done by a fairly inexperienced guy one time that got pimples in a fairly short time because of water in the primer, but that might have been from a poor compressor setup - it does happen

gives ya something to chew on till an expert comes along

Bill

Sounds like nonsense to me. I have never had a need to wet sand bondo but it's important to wet sand primer. Otherwise your sandpaper will get clogged after two passes. Don't worry about it. Wet sand when you need to and let it dry before painting.

Don't get it wet.I had rust cut out of an Australian '69 Falcon and was told to get it painted straight away, but the filler got damp and once it was painted came up in bubbles, especially on hot days.It will definately absorb moisture.

You don't have much choice but to get the bondo wet. After you get it sanded down, THE ONLY way to remove the fine dust from the micropours is to go over it with a damp sponge or rag, OR hose it down. If you're worried about painting over damp bondo just put the car in the sun for a few hours, then prime. I have NEVER had a problem with moisture bubbles under the paint but I have seen them though. Common sense is the key.

You dont wet sand until you have the last coat of primer sealer applied then wet sand with 600 or finer to remove any samll imperfections.then blow off all the dust with an air hose and wipe it all down with laquer thinner then wipe it down with laquer thinner again.the last step should be to go over the entire surface with a tack cloth.