brushing lacquer

[Dan of SC]

OK, my spray gun is cheap, my compressor is old, I can't seem to keep it going very well so I've decided to chuck it all and try a brush. Probably better for the environment anyway, and at 65 I don't expect to see an instrument I built in some museum. I bought a can of Watco brushing lacquer at Lowe's and some of those cheap foam brushes. It says on the can to use a good bristle brush but I've heard many people tell me they get a real smooth finish with the foam. So anyway I tried a sample piece of wood, sanded it down to 220, brushed on 3 coats full strength. I did get a couple of air bubbles which would sand out pretty easily, so I thinned out a final coat about 1/4 thinner and it looks pretty good, no bubbles. Anybody have any similar experience or advice? Thanks, Danny Gray

[fscotte]

You can find a Badger 350 airbrush relatively cheaply online, or Ebay. That's what I use, and works fine.

[multidon]

I did a refinishing project once using Minwax Brushing Lacquer and used foam brushes. Big mistake! The lacquer melted the brush and left little black specks in the finish. Lesson learned. Had to sand down and switch to a bristle brush. This left brush marks and required lots of sanding and rubbing out. Not a pleasant experience.

I looked up the Watco. It is different stuff from the Minwax which is straight up nitrocellulose, and requires lacquer thinner. The Watco contains nitro too but also alkyd resins and rosin. This makes it a link of lacquer/varnish hybrid. The solvent list does not include methyl ethyl ketone which may have been the culprit in my brush dissolving experience.

I would advise anyone using foam brushes to check for compatibility with the finish solvents first. Foam brushes work great with oil based varnishes I have used and don't seem to be affected by mineral spirits in my experience.

[Vernon Hughes]

Forget the foam,buy an expensive bristle brush.

[Dale Ludewig]

never mind.

[Marty Jacobson]

There's not really a simple answer here. I've heard that lacquer can be brushed, but I've never attempted to make that work. I have a $1500 spray system that I bought secondhand for $150. After using it to shoot about 30 gallons of various substances, I'm starting to get comfortable with it. I suspect the same kind of learning curve applies, whichever method you choose. Pick one and go for it. Patience is the most important piece of equipment to bring into the finishing booth.

[Michael Lewis]

In my experience brushing lacquer is not for brushing. Lacquer dries so quickly it is VERY difficult to avoid significant brush marks. If you want to brush on a finish try oil based varnish and foam brushes. I suggest a phenolic resin type oil varnish so it dries hard and quickly. Thin it a bit so it flows out to avoid brush marks. I never could get that to work with lacquer.

[Dan of SC]

never mind.
Are you saying I should find another hobby?

[Dale Ludewig]

Hah! No, I was going to basically say exactly what Michael and Marty said. But I was getting too wordy. :)

[multidon]

Agree with the above 100 percent based on my experience. "Brushing lacquer" is an oxymoron. They really do a disservice to hobbyists by making them think this is a viable option. It took me forever to get the brush marks off.

Of course as noted above the Watco is a relatively new product and if I read the label correctly it is not exactly pure lacquer but a lacquer/varnish hybrid with alkyd resin included. Dan says he thinned the final coat but did not say what he thinned it with. There is no MEK on the solvent list But a related chemical methyl isobutyl ketone is on the list plus a real witches brew of other solvents. Maybe there is a propiotary thinner?

Even though it seemed to work for Dan I am dubious. It could be sprayed. Probably would turn out better. If you don't have a spray gun the same product is available in a rattle can. Or there is the Preval sprayer, with the glass jar underneath and propellant above. The results from this kind of spraying can be perfectly acceptable if you are willing to spend more time rubbing out.

The biggest reason I am dubious about brushing on this product is the "dry in 30 minutes" advertising claim. If you read the label this means "dry to the touch" and" you may put on another coat at that point. I can't see how there would be enough time for flow out with only 30 minutes brushing it on. Brush marks are inevitable. And your working time would be incredibly short. You would basically get one shot with no ability to go over any mistakes a second time. The label also says do not use finished object for 24 hrs. So the 30 minute claim is misleading. And like any other finish I would expect it to take several weeks at least to fully cure.

It kind of upsets me to see products like this marketed to amateurs when you really need to know what you are doing to use them. By the way this product is actually made by Rustoleum and marketed under their brand as well. Same thing different name.

Sorry to be so wordy. Long story short, I would find a way to spray it.

[sliebers]

I've sprayed Watco brushing lacquer. It can be thinned with lacquer thinner. I believe there is some nitrocellulose in it, but there are other things as well. It sprayed successfully and buffed out to a high gloss. The problem I had with it was it cures too hard. It gets brittle and chips and cracks very easily. While a brittle finish might be good for tone, it doesn't flex enough to be a durable finish.
I have not tried brushing it. I decided to abandon using the finish for anything serious because of the hardness. I wanted it to work. It would be so nice to run down to the local hardware chain and buy what I need. No such luck in my case. I've moved on to McFadden's formula that Seagrave makes, but now it's just too expensive. I've done some tests with Cardinal lacquer recently and like that. It's about half the price of Seagrave.

[Dan of SC]

This product may have extra ingredients, but it smells exactly like Behlen stringed instrument lacquer. Don't they make lacquer retarder that slows drying? Maybe this is just lacquer with retarder? I know nothing about chemistry. I thinned the final coat with lacquer thinner. Thanks, Danny Gray

[multidon]

Dan the chemistry of lacquer is pretty complex. Most finishes are matched with single solvent thinners. Lacquer thinner contains several different solvents from several different solvent families. Some of them actually dissolve the lacquer solids others simply dilute to affect drying time. They all evaporate at different rates. You are correct that there is such a thing as lacquer retarder to slow drying. This is usually used in humid conditions to prevent blush, when moisture gets trapped under the lacquer.

Many lacquer manufacturers make a line of thinners and retarders specifically matched and engineered to work best with their particular lacquer formulae. Watco does not seem to do this. If you use general purpose lacquer thinner and lacquer retarder from the hardware store its a crap shoot. The makers of those products are basically guessing what the lacquer formula will be. For example, your off the shelf multipurpose lacquer thinner will probably contain methyl ethyl ketone. Watco uses methyl isobutyl ketone. Similar but not the same. Is it close enough? Who knows? When you use a lacquer system where all the chemicals are matched there is no doubt.

If you are determined to persue your present course, and it seems like you are, then I would say you should practice on scrap. A lot more than just once. Until you find a combination of lacquer, thinner, and retarder that works for you. But I am shocked that you haven't had a problem yet with the lacquer thinners melting the foam brushes. I am puzzled as to why you seem resistant to rattle cans or disposable Preval sprayers. These are really good options for those without access to spray equipment, as long as you have a well ventilated working area.

[Dan of SC]

Dan the chemistry of lacquer is pretty complex. Most finishes are matched with single solvent thinners. Lacquer thinner contains several different solvents from several different solvent families. Some of them actually dissolve the lacquer solids others simply dilute to affect drying time. They all evaporate at different rates. You are correct that there is such a thing as lacquer retarder to slow drying. This is usually used in humid conditions to prevent blush, when moisture gets trapped under the lacquer.

Many lacquer manufacturers make a line of thinners and retarders specifically matched and engineered to work best with their particular lacquer formulae. Watco does not seem to do this. If you use general purpose lacquer thinner and lacquer retarder from the hardware store its a crap shoot. The makers of those products are basically guessing what the lacquer formula will be. For example, your off the shelf multipurpose lacquer thinner will probably contain methyl ethyl ketone. Watco uses methyl isobutyl ketone. Similar but not the same. Is it close enough? Who knows? When you use a lacquer system where all the chemicals are matched there is no doubt.

If you are determined to persue your present course, and it seems like you are, then I would say you should practice on scrap. A lot more than just once. Until you find a combination of lacquer, thinner, and retarder that works for you. But I am shocked that you haven't had a problem yet with the lacquer thinners melting the foam brushes. I am puzzled as to why you seem resistant to rattle cans or disposable Preval sprayers. These are really good options for those without access to spray equipment, as long as you have a well ventilated working area.

Don, thanks for your interest and your reply. I,m not rich but I could easily buy a whole new spray system, but I'm kind of a tightwad and I do have other interests, travel probably my favorite, domestic as well as international. Also, when I do spray then go outside the smell is awful. I'd rather not put that solvent into the atmosphere. I care a great deal about the environment and the future of the planet. Enough of that. The foam brushes did not dissolve but when I thinned a little for the final coat I did so in a plastic cup. I left the near empty cup sitting on a board and forgot about it. I later found the bottom of of the cup had partially dissolved and the small amount of finish had run across the board. Now I'm thinking maybe I'll buy some Behlen lacquer, thinner, and retarder and experiment with brushing that. Danny

[multidon]

Dan, if you are concerned about the environment I would submit to you that it doesn't matter whether you brush or spray. Since lacquer finishes work by evaporation the solvents will end up in the atmosphere regardless of the application method. I wonder if you have ever looked into the KTM water based finish carried by LMI? People have reported great results with it and some high end luthiers are using it. They say it looks just like lacquer, is water based and environmentally friendly, and can be brushed or sprayed.

I have never used it myself but it does get good reviews.

[Dan of SC]

Don, I hate to belabor a point but I think brushing probably puts a lot less solvents in the air because no overspray. I did use a Minwax water based product once I believe called Polycrylic on some finished trim in a house I built for myself. It was crappy. Seems like sunlight would somehow make it just disappear. That was about 15 years ago, maybe this new stuff you mention is better. I guess it wouldn't hurt to try. Thanks, Danny Gray

[High Lonesome Valley]

Dan, have you considered a slow cure oil finish like boiled linseed or Danish oil?

Maybe even learn to french polish, which is a joy all in itself.