I wrote this for another forum; should cover most of your questions.
On a good paint job (which are all I do :-) I would spend a minimum of $400 in materials prepping that car (not including paint). I use only catalyst-hardened primers & paints, starting with PPG epoxy primer & building up imperfections for blocking with Sikkens high-build primer (if needed). Then another coat of epoxy as a sealer before spraying a *minimum* amount of basecoat color(s) (just enough to cover well) & topping off with Sikkens clear. I keep buildup to a minimum to minimize chipping. These paint jobs will last for at least 20 years if the car is parked outside; probably 50 or more if taken care of. Just wanted to prepare you for the sticker shock when you start buying materials. Of course, you can cut alot of corners, & you most likely won't use the high-dollar Sikkens stuff. But it appears that you plan to have someone else shoot the paint, so ask them about sealing it with epoxy, as it will minimixe shrinking & make the paint stick better. Use base-coat clear-coat to guard against UV rays (the clear keeps it from fading). Here again, the paint & clear cost may be higher than a soild color, but it'll be worth it. If you want to do it right, take EVERYTHING off of the car that you can; all trim, door handles, lights, etc. Sand it THOROUGHLY, all the way up & into the corners & crevices. CLEAN it THOROUGHLY with a good "wax & grease remover": wipe it on with a clean cloth & wipe it dry with another clean cloth - don't let it air dry. Do it twice to make sure you get all the wax & grease off of the surface. DO IT A DOZEN TIMES BEFORE PAINTING IF YOU'VE BEEN USING SILICONE ANY WHERE AROUND THE VEHICLE. Well maybe not a dozen, but AT LEAST three. Silicone will travel through the air for hundreds of feet, & make the paint "fisheye" (seperate from the surface leaving small craters). Well, those paragraphs kinda get ahead of us here... Anyway, here is the basic sequence you'll want to use.
1) Metal work. This means hammering out/working the dents, changing parts like fenders, & lining up all the body panels (hood, fenders, doors, & trunklid). A good rule of thumb when working metal is to use two blows instead of one; that is, work out the dents slowly so as to not stretch the metal. Start with lining the doors to fit the body at the 1/4 panel & around the opening. Then line the fenders to the doors, & the hood to the fenders.
2) Stripping. You may not need to, but probably will 'cause most older cars have alot of paint on them & it's not a solid base to shoot over. The DA I mentioned before - if you find a
*real* DA that locks down - will usually do a good job of taking it down to bare metal using 80 grit in the lock-down mode. I use an 8-inch air buffer & 80 grit most of the time. If that dosen't work (if the paint is too soft & fills up the paper too soon) use a chemical stripper. I use "Aircraft Stripper" (brand name).
3) Filler. This means bondo :-) Use any good brand name, the new ones with "micro spheres" are probably the best. If you strip the car to metal, & have the money to spend, go ahead & put one good thick (not reduced) coat of epoxy on it. If not, grind ALL the paint off of the areas that need filling back several inches beyond the dented area. You do not want bondo over anything but bare metal (or fiberglass) or epoxy primer - no exceptions! Sand the bondo with 40 grit to start with. When you've got it just about right, finish with 80 grit. Use a flat block on the flat areas & whatever it takes on the rounded contours. Any block that fits your hand & the sandpaper will work. On "outside" rounded areas the flat block will work if you "roll" it over the surface diagonally at 45 degrees in both directions. On inside curves, use a flexable pad or peice of PVC - things like that. Always change directions when sanding, & try not to sand in a straight line.
4) Priming/blocking. Once you're finished with the filler, prime it. I again use a coat of epoxy & then two or three coats if needed of high-build primer on the areas that were worked.
*Very important* - give the primer several days if you can to completely dry before blocking. Spray some black "guide coat" paint (flat black laquer works well) over the primed areas in a very light mist. Don't try to cover the surface, just let a light mist fall on it. Block the primer using a block or if you can find one a good paint paddle. For large flat areas, Home Depot has some
5-gallon paddles that work well, On smaller areas & rounded surfaces a regular paddle works well if you can find a flat/straight one. The smaller one will flex a little, allowing you to put pressure where you need it (on the high spots & rounded surfaces) to knock the surface down. Wrap the full sheet of paper around the paddle & tear off two sides as the paper wears out. Start with 180 grit - wet if you can, with a trickle flowing over the surface as you sand. Finish with 220 to 320 grit. The high/low spots will become apparent as soon as you start sanding using the guide coat. Block everything untill it's smooth - all the guide coat will be gone. One thing to remember: when initially trying to flatten an apparent low spot, you have to sand the entire area around it down to where that surface is - you don't actually sand the spot that's not smooth untill the area around it is down. If an area is too low to block out (you start to hit metal), use a catalyst-hardened putty to fill it. I use Fiberglass Evercoat (brand name) I think it's #406. Re-prime the blocked areas. If needed, block & re-prime again. Again let the primer dry.
5) If everything looks good, it should be ready to sand & shoot. Sand with
400 or 500 wet (500 for base-clear). On older cars that have rubber around the glass, you can usually use 1/8 inch rope under the edge of the rubber to hold up the rubber & paint under it. Size of rope depends on the car/rubber. If 1/8 dissapears, use larger.
*Very important* - clean the surface with wax & grease remover as mentioned above. Shoot the paint.
6) For a
*nice* clear-coat finish, sand with 1000 or 1200 grit wet using a firm "sponge pad". On rounded areas, a softer sponge pad works well. They're available at the auto paint store (or should be). Buff with a "micro-finishing" compound & polish/clean with a product for new paint (foam polishing pad glaze). Don't paste wax until the paint has dried a
*least* a month.
Hows that? ;^p Any questions? ~ Paul aka "Tha Driver"
Giggle Cream - it makes dessert *funny*!