How do you achieve a high gloss black finish on metal?

Question

I want to paint cast aluminium, for use indoors only, and achieve a mirror like ultra smooth high gloss black finish - as close to a piano black as possible

Answer 1

You don't say if it is for indoor or outdoor use on metal? If indoor, or outdoor and not exposed to direct UV light (sunlight), I'd use RustSeal by KBS Coatings. It's a brilliant smooth glossy black finish that will also serve as a permanent coating againt rust & corrosion. It is so smooth and shiny, it stays looking wet. It is also self-leveling... brush or roller marks will smooth out and people will think you've sprayed it on! It's just amazing stuff to work with. We use it on car frames. It restores them better than new!

Answer 2

Like getting a smooth finish on anything else, your surface has to be smooth first. Since this is aluminum, that shouldn't be a huge problem if there aren't too many "draws" (defects or raised details) in the surface. Start by wet-sanding with 400 or 600 grit wet-dry sandpaper (no, ordinary sandpaper won't work... it'll just fall apart). If there are deep pits in the surface, you can buy aluminum-based fillers in a hardware or auto parts store to clean them up. Once you've done all you can with the sandpaper, rub it out with a good rubbing compound, and follow on with a polishing compound. Now you're ready to start painting.

I always start with 1 or 2 coats of good automotive primer. (For your purposes, the color's not important. In some applications though it can be.) Give the primer plenty of time to dry, then rub it out with the polishing compound. Recoat if necessary and rub out again. If you've done it right, you will have taken the "roughness" out of the primer coat and you should see a sheen even though the paint itself is a matte finish.

Now this is the weird part, but trust me okay? What I do next is spray on a coat of high-gloss WHITE. By doing that, I know whatever color I spray on next will be "true". Again, rub it out with the rubbing and polishing compounds and wet sand if needed to smooth out any runs (which will probably require a touchup of the paint).

Now comes the color coat(s). Since you're doing solid black, it's not all that tricky. Spray it, and rub it out. Recoat and rub out as needed to get the finish you want.

Clearcoating isn't strictly necessary if you've done a solid job of finishing the previous coats, but it can help with durability. There are lots of options -- automotive laquer, polyurethane, epoxy-based. Just make sure the clearcoat you use is compatible with the colorcoat. I used a clearcoat over an enamel once and the clearcoat "attacked" the colorcoat resulting in what looked like spiderweb cracks in the colorcoat. Fortunately the colorcoat was a metallic and the "cracks" weren't noticeable unless you looked really closely or knew they were there. Lesson learned: Test on a scrap piece of something first!

This sounds like a lot of work I know, but the results are worth it. I've used this method on wood and gotten a finish that would have passed for metal even on reasonably close (visual) inspection. I also used it on an old bicycle that I was rebuilding from the frame up and got spectacular results (that was when I discovered the white undercoat trick -- gray primer turns neon pink into cherry red!)

You can spend as much as you want to on paint, but if you take your time and stick to the procedure, you can get results just as good with ordinary spray enamel as you could with an exotic (and expensive) paint. Patience is the key!

Answer 3

First Prime it, two times- then paint it with High gloss- small job use a spray can, and fog on a coat first, then another and another, don't try to get the finish all in one coat, it will run. If this is a Car or real nice- you must Wet sand the finish to make it outstanding.

Answer 4

B&Q do a great aerosol spray in High Gloss Black especially designed for metal use. I have used it and it is great - covered well, didnt make too much mess, or smell too harsh and it has lasted 6 months now with no flaking, peeling or scratching.

Answer 5

Use a Hi-gloss black paint.

Answer 6

I would paint semi gloss orange. let dry. then apply a high gloss polyurethane. keep laying on clear coats until the look is desired.You may want to start on a mock up piece first.

Answer 7

High gloss spray paint Clearcoat polyurathane'

Answer 8

High gloss black paint (spray) 2 or 3 coats
then clear lacquer, clear lacquer, clear lacquer, clear lacquer,
wet sand between each coat of lacquer

(ever been to a custom car show?)

Answer 9

get a oil based paint (high gloss) paint it on with a foam roller. it will turn out like you would not believe. everything else leaves marks and streaks

Answer 10

use a Spray paint like "Hammeright Gloss " ... its very good or even a Good Car paint ...