I'm looking at maybe painting my car myself. However I would want to use a silver metallic base coat and a clear coat system.

Since in a garage environment it's almost impossible to avoid dust etc in the paint : is it possible to sand the metallic base coat with a very fine wet sandpaper ? I know this is possible for the clear coat, but I'm doubting it would be possible for the metallic since it would disturb the pattern of the metal flakes. I'm I right ?

 

Correct.

However, you might get away with very lightly remove nibs.

Best thing to do is to set up a filtered air system in your garage.
Also, use a Tyvec suit. Most dust comes from you clothes when painting a car.

Be careful with wetting the floor. It can cause other problems due to the humidity.

 

Working in the prototype field since about "89", i can tell you we almost always sand the metallic or pearl, after 2 or 3 coats, we allow a good long flash time, maybe 45 minutes to an hour, then we will "nub" dirt spots and lightly scuff almost entire car with 1000 grit or finer (WET) then wipe the car down again, apply last coat of base as well as a "drop coat" to balance the flake or pearl. the last procedure is usually a medium wet coat, and with the drop coat, we turn down the fluid pressure and turn up the air pressure. you are only wanting to apply a light even dusting of flake. that is just how we do it, 20 painters will probably give you 20 different procedures, this is just one possibilty. Silver is one of the toughest to do without getting blotches or tigerstriping. but take your time and check your pattern after every coat, make adjustments until you are happy, scuff, final coat,drop coat and clear. Good luck with it. let me know how it comes out.

 

Oldschool, ( "nub" dirt spots and lightly scuff almost entire car with 1000 grit or finer (WET) then wipe the car down again, apply last coat of base ) What do you use to wipe car down with after de-nibbing base coat ??

 

Generally i will just used a damp towel, during scuffing (wet sanding 1000) try to keep vehicle as dry as possible,,scuff an area/dry it. using a damp towel and a dry towel to follow. make sure no water remains. tack again with tack-rag and begin painting again

 

Here's the thing, you can sand some mfgrs basecoats, but not most. Here's why: Most mfgrs basecoats you use an additive which contains parafin (basically wax). If you sand it, regardless of screwing up the metal flake finish, which you WILL do on silver, you will loose adhesion of the top coats from there on. That's why most say not to sand the top coat. Now, you can rub out some minor nibs, usually those can be mashed down or worked out with a fingernail, or lightly wetsanded with 600 or 1000 grit. Between coats you can very gently run a piece of 1000 gt that has been moisted with water over the finish to 'de-nib' the finish, but you're not doing any real sanding per se. But you wouldn't do it on your top coat with metalic. And runs, you don't have a choise but to wetsand gently but you have to put on another coat. Anyway, in general, don't do it.

Back to your main point, it's a fallacy that you can't get a good paint job in your driveway. A lot of really nice show quality paint jobs are done in people's garages and driveways. I've personally painted dozens of cars in my driveway or garage. I prefer to paint outside because the lighting is perfect and you can see everything. Only problem is you can't control the environment (sun, leaves, sprinkling, cotton wood, bugs, etc), therefore, shops that need to rely on good paint jobs day in/out use a booth. A lot of crappy jobs come out of booths too (dust, runs/sags due to bad lighting). I was in a booth and a guy came in and the door slammed shut and a bunch of dust from the ceiling sprinkled nicely into the paint!

Painting with base/clear is liberating because even if you get some dust in the paint (and don't sweat it, you will), you can wetsand/buff it out and you can eliminate those imperfectins. Small dust nibs will be totally unnoticable once buffed ...so will those bug legs!

The best thing to do is wet the floor prior to painting. Get lots of light in your garage, not incadescent. My garage is like a surgery center it's so well lit. I put in all T8's top and sides. I even painted the walls and ceiling white! I wouldn't get too carried away putting plastic up all over unless you have exposed rafters. That's getting carried away. Just blow everything off really well above the car.

Wear a tyvek paint suit as the other guy posted (most dust actually comes from the painter), wear a head sock (no hair in paint) which you can buy at a paint store for $2. And of course an approved respirator or SAS. Remember these paints can be deadly appropriate measures aren't taken. Make sure your garage is well lit. Don't paint at night as bugs, and worse yet, MOTHS, are attracted to light and will see the reflection in the paint and guess what?? Start in the morning cause base/clear takes a long time to paint. A cooler morning is best. Knock down any nibs between coats but don't 'sand' a lot. Don't get worked up over some dust, it's gonna happen. Plan on wet sanding and buffing.

I'm painting mine silver too here pretty soon. For the novice silver is probably the hardest color to start with (next to gold). Tiger striping is the thing hardest to avoid, even for experienced painters. If you get it on too thick and wet you can get metal flake run, which looks awful and can't be corrected (but can be covered up on the next coat). You need to paint, like the hood, in different patterns (45 degree angles) for different coat, and then at the end, you go around and 'fog' the panel. That evens out the metal flake. I do it on the last coat after I paint each panel so it 'melts' in better. The clear will make it smooth again. If I can find a nice cool morning I plan to paint mine outside. Otherwise, I'll paint it with the garage doors open (to let the overspray waft out).

Paint is truely rewarding. For silver, that is one color I would encourage you to practice on a junk panel. Any bodyshop would be happy to give you a scrap fender (less for them to scrap out) to practice on. A Hood is what you really need. Fenders don't show stripes much, hoods do.

Check out my website too for paint tips: www.repairnation.com. I've made every mistake in the book over the last 30 years, so I help others try to avoid. Oh, I quit answering my web email.

Good luck

 

THX