New guy help

[5.0MX5]

First of all, this is a great site and hello! I'm a very hobbist painter (horse trailers, tractors etc.) and am trying to paint my project car. A 1990 Miata with a 302. It's a northern car and I've spent the last few weeks cutting out rust and welding in new metal. I've also changed the hood and one quarter from a parts car I picked up cheap and that's the reason for these questions.

I have bad shoulders and sanding is a problem, the hood and quarter from the parts car had a recient repaint with clear that's super tough to sand. Due to my shoulders I need to do this with minimum removal of the paint on the replacement parts by hand sanding (I do have a DA but my compressor is too small). Can I just shoot everything with epoxy primer to seal it, then go with a high fill primer, sand and level, then straight to either the base or acrylic urethane (haven't decided on what to use on this very BUDGET job).

I realize the best option would be to remove all the unkowns and go to metal, but that's just not an option.

Thanks, RR

[Len]

Hi RR, welcome aboard.

As long as the existing paint is not cracking or peeling you should be able to apply your new paint on top. The only time you may have a problem is if the old paint is not compatible with the new paint but that is unlikely unless the old paint is lacquer. You should sand the old paint with something like 400 to 600 grit paper and you can apply your new paint right on top. Epoxy primer is needed if you have exposed metal and filler primer is needed if you have surface irregularities that you want to level.

[jcbluescooby]

Len,

I will also be painting a car with a pretty much fresh paint job on it, no peeling or cracking. I bought 600 grit sand paper for my DA sander. This might be a dumb question but when you say use 400 or 600 grit do you mean wet or dry? Im assuming dry for the initial sanding. Would you recommend I use 400 or 600 grit to start with. I am painting a 2004 Forester so the paint is relatively still pretty much new. Clear coat is still glossy.

Henry

[Len]

Len,

I will also be painting a car with a pretty much fresh paint job on it, no peeling or cracking. I bought 600 grit sand paper for my DA sander. This might be a dumb question but when you say use 400 or 600 grit do you mean wet or dry? Im assuming dry for the initial sanding. Would you recommend I use 400 or 600 grit to start with. I am painting a 2004 Forester so the paint is relatively still pretty much new. Clear coat is still glossy.

Henry

Wet paper is a little more coarse than dry so a 400 wet is more coarse than 400 dry. A "good" urethane will stick well to a very fine scratch (1000 to 1500) and a metallic can show coarse scratches so it's usually best to go finer rather than more coarse. If the color is a metallic I'd recommend going with 600 wet or finer if it's a solid color you could go as coarse as 320 using a "good" base clear. Less expensive paints may not cover scratches as well and they may not be as forgiving to sanding and polishing.

[5.0MX5]

Len, BIG thanks for the quick reply the other day. I just shot my epoxy sealer today. The car has a fiberglas body kit that I can't easily do away with (wish I could) due to the mods already made to accomidate it. After bonding it to the car with 3M 8115 and lots of work, the sealer told me I still have tons of work to do.

I'm giving the epoxy 24 hrs. to dry, then hitting it with 180 and working on the fiberglas some more.

Thanks, RR

[Len]

Len, BIG thanks for the quick reply the other day. I just shot my epoxy sealer today. The car has a fiberglas body kit that I can't easily do away with (wish I could) due to the mods already made to accomidate it. After bonding it to the car with 3M 8115 and lots of work, the sealer told me I still have tons of work to do.

I'm giving the epoxy 24 hrs. to dry, then hitting it with 180 and working on the fiberglas some more.

Thanks, RR

The best thing I've found to tweak the unevenness of fiberglass bodies is spraying a coat of polyester filler llike Slick Sand over then entire surface then guide coat and block sand. I'll sometimes need two coats to get it flat then I hit it with a 2K or (depending on the paint) just a sealer then my color. I stopped selling Slick Sand for now because it's difficult to ship but you can probably pick it up locally. You should have a 2.2 tip or larger to spray SS.