Cabinet finish - When to buff out?

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I'm aiming for my first high/mirror gloss finish. The cabinets have been sealed, primed (18 coats sprayed), and three coats of gloss black sprayed on.

At the moment wet sanding the top coat with 1200 grit results in a matt finish so I wasn't sure whether I need to cut and buff out now, or only after the final clear coat has been applied.

It's gone well so far, I don't want to mess it up at the last stage... ;)
 
I don't see a need to go all the way to 1200 grit before the final coat. I usually do 320 between coats, 400 before and after the last black, then 320 on the clears and 400 before the last clear coat.

It is VERY important to get to the point that the surface is uniform before proceeding to the next grit, as Al said. I'd go a step further and say be sure that the sanding marks are all in the same direction. My hand sanding tends to go in ellipses, and is shows through the topcoats. Also be sure to clean the surface thoroughly between grits. A piece of 400 grit sludge will ruin your 600 grit efforts in a heartbeat.

Depending on your spraying technique, you'll probably want even more clear that Al suggests before rubbing out to ensure that you don't rub through the clear.

Be sure to let the finish fully cure before buffing out. (several weeks for lacquer) Depending on the compound you use, you can stop at 1200 grit. If you go to 1500 or 2000 you can skip the rubbing compounds and go straight to polish. Take a look at 3M's automotive rubbing/polishing compounds. Manzerna also makes excellent compounds. I used their polish sticks on a domet flannel buff chucked in a drill with excellent results.
 
Hard to argue when your right!

I don't see a need to go all the way to 1200 grit before the final coat. I usually do 320 between coats, 400 before and after the last black, then 320 on the clears and 400 before the last clear coat.

It is VERY important to get to the point that the surface is uniform before proceeding to the next grit, as Al said. I'd go a step further and say be sure that the sanding marks are all in the same direction. My hand sanding tends to go in ellipses, and is shows through the topcoats. Also be sure to clean the surface thoroughly between grits. A piece of 400 grit sludge will ruin your 600 grit efforts in a heartbeat.

Depending on your spraying technique, you'll probably want even more clear that Al suggests before rubbing out to ensure that you don't rub through the clear.

Be sure to let the finish fully cure before buffing out. (several weeks for lacquer) Depending on the compound you use, you can stop at 1200 grit. If you go to 1500 or 2000 you can skip the rubbing compounds and go straight to polish.

This dude knows his stuff!

MArk
 
Yup, loads and loads of coats of lacquer - I apply up to 10 fairly thick coats if I'm painting somthing important.

I have found flatting the penultimate coat of base but not the final coat gives better results provided the final base coat goes on well and dries flat and shiny.

I apply about 5 coats of lacquer, flat them after a week of so, apply the final 5 and polish out the surface a week or so later.

My tips are... Place the cans in water at about 40 degrees for 20 mins before spraying and I use a bit of carpet in a plastic bag as a sanding block to ensure even pressure across the surface of the sandpaper.

Be careful of the edges when sanding ;) The number of times I went through an edge or corner is unbelieveable...

I learned the hard way too ;) :D Some of my early efforts were shockingly bad :D
 
And don't let anything touch the surface until the finish is fully hardened.
I put a lot of work into giving a front panel a piano black finish. Several days later, when the laquer was completely hard to the touch, I placed a light aluminium knob on it, just to see how it would look, and fogot about it overnight. By the next day it had sunk into the laquer, leaving a prominent ring mark:(
 
This is the stuff I will be using for the clear coat: http://www.paints4u.com/ProductDetails.aspx?productID=3166

I've used the same U-POL stuff for the primer and basecoat.

What is the time required to fully harden? I've also been sanding down after only letting it dry overnight, or sometimes less.

Bob, I've been using only 600 grit directly after every four coats of primer, and I just tried going straight to 1200 after applying three base coats. It gives smooth results fairly easily and avoids digging back into the primer coats.

I tried buffing out a small patch after sanding the basecoat to 1200 grit using automotive rubbing compound, and the results were excellent. I'm happy with the finish there, but I assumed the clear coat is then applied primarily as a protective layer. Is this right?

I also wondered whether clear coating the matt finish base coat (sanded 1200 grit) would bring back the full gloss once the clear coat is applied. I think PM has answered this one.
 
If you're spraying a coat flat enough that 600 grit really flattens it, you're doing a lot better than me. Every spray leaves a bit of orange peel. Using too fine a grit will follow the contours of teh orange peel, leaving a less than flat surface. Depending on how large the surface is, it may not be noticable. But for a really flat surface that looks like a mirror start at 320 and work up.

The clear coats add "depth of image" - makes it look more like a pool of black glass. They do add protection for custom paint jobs - flames, metalflake, pearls, etc.

I always shoot a little extra finish on the edges to help avoid sanding through.

Your finish looks like a standard lacquer. You can safely shoot several coats in a day, let it harden overnight and sand out. Give it a week or more before the final rubout. If you do a good job between coats, it ought to look decent enough while you wait to harden.
 
Update

I started again more or less - this time with a compressor and spray gun to hand. A little different to spray cans I'll say!

Cellulose primer and basecoat. Some coil heaters work wonders in keeping the temperature up for a better spraying environment.

I'm in two minds whether to clearcoat them or just to flat back and polish without. I've been told that black is the one colour that doesn't need the clearcoats (by the paint suppliers) :xeye:

I've lost count in the number of primer coats sprayed, which was basically to ensure that the joints don't show through. However I stuck them in front of the gas fire after finishing the basecoats rather then waiting a week(s) to move on to the next stage - the shrink back is amazing! Those stinking joints have come through.

I'm thinking of sanding straight to 1200grit, then a rubbing compound (Halfords), then to some Meguires fine cutting polish.

Any comments welcomed.

An externally hosted image should be here but it was not working when we last tested it.
 
And here's the DIY spray booth
 

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Good job spraying. Isn't the difference between gun and can amazing? Your booth looks like mine :)

The black lacquer I sprayed did not need a clear coat to look good. Pianolac does, but that is a different system. Hey, if the paint supplier is telling you that you DON'T need to buy more from him, that's saying something ;)

Take your time working through the grits. Get almost all of the orange peel with 320 grit before going to 400. The spots left after 320 should be very shallow. By the time you are done with 400 grit, there should be NO orange peel. From there you are just removing the sanding scratches until you can use the compound.

Be careful at the edges. Keep the pressure on your block over the flat surface so you don't sand through.
 
Great looks, Vikash....
Heating to say 50-60 deg (as we are dealing with wood) at least overnight, should speed up the hardening process quite considederably....
this is the classical way of doing it with cars..
Don't know about the modern water based stuff, though...
The garage guys should know I guess
 
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