Old Masters nitrocellulose lacquer problems

[crisw]

I'm using Old Masters Satin Clear Wood Finish, which is a nitrocellulose lacquer, for the first time. I am having some problems with it, but I am not sure if they are related to my technique or some other problem.

I put the first coat on my projects last night. Most of them had bubbles that dried hard. In addition, the first coat finish looked patchy- some areas dull and some shiny. Is this normal?

I'm using a synthetic bristle brush. The label says to "flow on a full coat"- how thick should that coat be? Could some of my problems be from the first coat being too thin? Can I put on a coat of this stuff that is too thick?

Is this finish sensitive to drying temperatures? It's fairly chilly where I am; the room is probably about 60-65 degrees. Will that retard the drying time?

Does this finish have an expiration date? The can had been sitting on the shelf at the woodworking store for awhile.

I realize that I can't put another finish over the lacquer, so I want to get these pieces to turn out OK!

[Neal Moore]

You may be experiencing two problems. First you cannot shake the can to mix that stuff. That will cause tiny air bubbles to form in the laquer that will transfer to your project. It must be stirred thoroughly but carefully. Second, the ideal drying temperature is 70 to 75 degrees. If it's humid and cool in your work area that would explain the uneven appearance of the coating. Additionally, with Old Masters, you want to use as few brush strokes as possible while applying to avoid streaks and bubbles. You can probably lightly sand the dried bubbles out to a smooth finish and start over after the piece has thoroughly dried for a day or two. Hope this helps. I'm not a finishing expert but I Googled "Old Masters" products to get this info.....Good luck!!!

[crisw]

Thanks. I didn't shake it, and there are no bubbles in the can that I can see. They pop up after I apply the finish. It's cool, but it isn't humid (I am in Southern CA.) I'm trying to use as few brush strokes as possible- these are small pieces.

[crisw]

I just went and looked at the piece that I gave a second coat to over two hours ago, I tried using a heavier coat and as few brush strokes as possible. It's got several bubbles, several dull spots, and the shiny areas are extremely tacky.

I really think that the problem may be that this can is too old and the driers aren't working properly.

Can I apply another lacquer over this lacquer? I really need to do something to save these pieces...

[crisw]

Hmmm. doing some research it appears that wiping the pieces with lacquer thinner may even out the finish. Any tips on this?

[workin for wood]

Lots of great questions. Can't say I know all the laquer answers. I know that heavy finishes are best applied over a sealer first. The sealer is put on the wood to seal the grain from popping, and seals air holes in the fibers. If those holes aren't filled, air will try and come up through the finish. This is especially common with bar top finishes. One solution to pulling the bubbles through is using a propane torch and a small fan. You hold the torch above the surface, so you don't burn the finish, you use the fan to push the heat to the finish. The heat pulls the bubbles through. I heat gun would probably work too. Thick finishes work best in more warmth.

I'm going to suggest in the future trying an applicator instead of a brush. It's similar to a foam pad but has a backer. You find it at box stores in several sizes, it is most commonly used for finishing hardwood floors. You buy the smallest applicator and some replacement pads. It works better, almost like a squeegee.

I don't think you will even it out that well with laquer thinner. You want to even the gloss you have to wait 2 weeks after you apply the finish. Then you sand it and polish it. The more you polish, the higher the gloss will be. Buy some wet sandpaper, start at 320 and run up to at least 1000 grit. Then you can leave it be, you can wax it, or you can continue going higher in grit counts using plastic polishes, automotive polishes, stuff like that. Or you can buy a french polishing kit. Whatever you decide, I'd avoid wax as the final step. Just personal opinion, but over time wax dries out, decays, needs rejuvination. If it's a table, the wax allows rings to get on the laquer. Stuff like that.

Could the can be too old...sure. There should be a date on it somewhere. I would think within a couple years of manufacturing it should be fine if it wasn't opened before.

Remember though, no matter what, you can always expect at least a couple micro bubbles in laquer. Can't complain about that. Those get sanded out during your wet sand/buffing stage. Laquer should not be buffed for at least a couple weeks, maybe longer. It takes a long time to truly cure. Sanding too early will melt it.

[crisw]

Thanks!

Things are definitely looking better after two more coats as the day warmed up. I think I'll be able to live with the results.