first off, i would like to thank everyone who helps me out…i really appreciate any advice. k, i am trying to achieve a high gloss piano finish on mdf and am having problems. i have what i think are the right supplies, black lacquer, automotive paint, and high gloss black spray paint, along w/ mdf sealer, wet/dry sanding paper w/ grits 220 -2000, and polishing compound and carbona wax. so far, my attempts have produced an unattractive finish(thousands of tiny bubbles on one, and an evenly pebbled sort-of look….from the paint, on the other ). please be specific as possible, cus i don’t know woodworking or carpentry jargon or abbreviations.
thanks to all,
brad
Replies
Brad; I don't understand what you are doing with so many types of finish. I suggest that you use only the black lacquer. Lacquer will rewet itself with each coat minimizing the flaky look that can occur where one coat is sanded through and the coat beneath exposed. Most lacquers are also soft enough to make sanding them down a reasonable chore. If they are too soft they won't polish well though. So what you want is one of the harder laquers. Use a standard lacquer though, not a catalyzed lacquer. Try NOT to apply the lacquer in thick coats because that will sometimes result in the finish drying on the surface before the deeper parts of the coating dry. This situation results in bubbles forming as the VOC's (volatile organic compounds, or thinners) trapped below the skin formed on the surface of the coating attempt to escape and push the surface film up creating little bubbles all over. You should minimize sanding between coats for the lacquers but it is good to just lightly knock off any dust nibs or other "bumpies". This is my best advice any way, I don't regularly do the type of finish you are attempting so some others here may have more refined advice. I assume that you are working on test surfaces until you start getting the results you are looking for.
I don't know anything about "automotive finishes," but I think you need to be using nitrocelluse lacquer. You should sand the MDF, and spray a couple of coats of nitro sanding sealer, then sand those smooth. Then start spraying light coats of lacquer. Let'em dry at least 2 hours between coats, with a fan blowing on'em. If you get a nib or bug, knock it down with 220 sandpaper. After you have a nice smooth finish with no pits or imperfections, mix a "flash coat" of clear 50/50 nitro and thinner. Hit it with that, and you may not have to rub out any. If you don't get a good base, your hight gloss finish will show every imperfection.
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