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Be sure to see my other web page on finishing. But this separate page is because I have had several people ask why I switched to water based finishes - this page is built from my email correspondence with them. I did not switch because of concern for the environment (although that is nice), but because I get a better finish, easier.
There is little difference between brands of paint thinner or nitrocellulose lacquer or other solvent finishes. But you can't talk about water base finishes without talking about a specific brand.
I now use "Oxford" USL - Ulitma Spray Lacquer from Target Coatings as my primary indoor furniture finish. It is more expensive than solvent lacquer (think $10 per quart bought in quantity), but the percent solids are higher, so it takes fewer coats. It doesn't require substantial thinning with lacquer thinner. It has full burn-in - which I think is unique (or at least rare) among water base products. That means that if you mess up rubbing out or sanding, and go through the layers, you do not get witness lines that identify each coat of finish.
I learned the hard way that you can't (or at least shouldn't try) to rub out a satin or semi-gloss finish to get rid of flaws ... it really is hard to do well, and doesn't come out well. Some experts say it can't be done. Therefore I was gradually moving back to all gloss solvent lacquer (Sherwin Williams), when a number of my woodworking friends finally convinced me to try Target. They didn't just recommend "any" water base finish, but all of them specifically recommending Target USL. So I got a gallon to try it, see how it worked, and see if it could be rubbed to various sheens. I am now 21 gallons into Gloss Target USL, and getting ready to order more.
The gloss Target USL is really great to work with. It is self priming... you can use it on bare wood, like a sanding sealer. Arguably it may not bring out the color and grain as well as a coat of shellac or other first coat. I did a test with shellac primer on a scrap walnut plywood - half with shellac, half without - and almost couldn't tell the difference after the Target USL was applied. Then I sand the first coat with a ROS - Random Orbital Sander, giving a perfectly level surface to build on. That sanding powders nicely, does not gum the sandpaper.
The build coats go on well... scary white in the can, but no problem spraying without thinning, and get a significant build per coat. The outside back of a bookcase may not get anything after the first "prime" coat and a quick machine sanding to smooth any raised grain. The inside back of a bookcase, which gets no wear, may only get one build coat. The wear surfaces may get 3-4 build coats, depending on how good my technique is that day (If off, I make thinner coats, and do more of them). With full burn-in, there are no witness lines between the coats - no problem whether I do fewer heavier coats or more thin coats. I don't sand between coats except to "ask for forgiveness" if I mess up, such as a drool, except possibly before the last coat of many, to be sure I have a perfectly smooth surface.
If I need a satin finish, I machine sand 400, then 600, then rub quickly with a towel. (That satin is so nice, I have had a couple customers stroke the surface, put their face against it, and place an order if I promise to do the same for them.) For semi gloss, I may go to 800 before a quick rub with a towel. (The official recommendation is to wait a few days before rubbing, but I have had good results after only a few hours). Notice "machine sand"... this is really quick - not like the endless rubbing of nitrocellulose lacquer with steel wool. The exception is a large piece (a set of bookcases or an entertainment center) with open grain wood like oak. Since I probably haven't filled the grain, the recessed grain lines may be glossy when I rub the surface to a satin finish. In these cases, I do spray a final coat of satin USL.
For a high gloss, the finish is good just as sprayed (assuming the operator is having a good day). However, I got some Menzurna rubbing compounds/polishes - and got a near piano finish in no time at all, machine sanding to 800, then applying Menzurna with a pad on a ROS, then wiping clean, then the next Menzurna... I only used the first two of three or four available grits. ("2L" and "16"), and had a finish that was above the quality of the "gloss" finish from the gun, approaching the "grand piano" level of finish.
In good conditions, water base finishes dry almost immediately to "dust free" , and are dry to the touch in minutes. They are ready to recoat in an hour or so. But they aren't really cured for weeks. I don't have room in my shop to store a completed piece for weeks, so I just deliver it and explain that the finish is like concrete. It is dry, but it will continue to harden for weeks. They can use the furniture, but be gentle for the first few weeks. Nobody has complained.
Did I say I like the stuff?
I left my solvent lacquer in my spray gun... cleaned it every year or two. (The solvent keeps the lacquer dissolved, so no film forms in the gun.) Unlike solvent lacquer, you are supposed to take water based finishes out of, and clean, the gun, after each use (I stretch that to at least daily). But the last time I checked, it took 90 seconds to clean a pressure feed HVLP gun... it cleans very easily with warm water in a sink - nothing like the horrors of cleaning latex paint. An empty mustard squirt bottle helps force water through the feed tube and nozzle. Recently I forgot to clean the gun, and it worked fine the next day. And the next. Finally some of the dried lacquer from the inside of the paint cup started to plug the strainer. I'm back to cleaning daily, but it is fast and easy.
Target USL must be stirred well before use... there is no layer of heavy solids on the bottom of the can of gloss, but the many exotic chemicals in the finish have to be well mixed. It doesn't stink or burn, but I would rather not breathe it, so still spray outside. Water isn't the solvent, but when the water evaporates, the chemicals left do their thing, and dry almost as fast as solvent lacquer. I have sprayed solvent lacquer when the work piece is in the summer sun (over 100 degrees), but cannot spray early/late in the day because of humidity. With this water base lacquer, humidity is little or no problem, but it doesn't like the extreme heat of mid-day Texas. (I have pushed the limits on humidity, and can testify that it doesn't like to be rained on before it dries, but I have successfully sprayed outdoors late into the humid evening - until almost midnight, although it dries slower.)
I recommend moving the USL from the one or five gallon container to smaller containers, so it doesn't skin on the inside sides of the can (not surface skin, just finish on the container sides that doesn't stick to the coating inside the can). With some airtight juice containers (not all juice containers are airtight), I have had no skin, so I can just shake before filing the gun and spraying. In most cases, I don't even bother to strain any more. And a friend (who must be as cheap as me) points out that the strainers can be rinsed and reused.
Jerry Work (another retired computer guy turned woodworker) wrote a very informative 50 page manual on Target Coatings and related finishing techniques, see www.targetcoatings.com/manual.html
I have used USL on tables without problem, but I got a gallon of Target conversion varnish (EM-Tech 8000), which Jerry recommends for outdoor use like doors, or for extra hard counter/tabletops. It acted just like the USL - same spray technique. It doesn't claim to have burn-in, so I was careful to not rub through the top layer. It looked great, and in theory should be more durable on that walnut kitchen counter that I built for a client.
After using it for years, I learned that regular nitrocellulose lacquer is not approved by KCMA - Kitchen cabinet manufacturer's association. I did a bunch of tests, and found it wasn't damaged by wine, water, booze, soap, etc., but then had a piece that spent a few days next to the kitchen sink, and it had spots that wouldn't come out. I don't know what the spots were, but something that happened at the kitchen sink.
Catalyzed nitrocellulose lacquer is KCMA approved, but doesn't have the best test results.
Target USL lacquer is KCMA approved, and has very good KCMA test results - better than Catalyzed Lacquer. USL is an acrylic lacquer, not nitrocellulose, what I describe as a "high tech" finish (in other words, I can't explain the underlying technology).
I tried dissolving some of the film that I peeled off the inside of the Target USL can, in lacquer thinner, and it didn't dissolve, although I couldn't guarantee that lacquer thinner didn't attack it. Further research possible, but not done.
The Target USL has full burn-in to lower layers of similar finish. But Target now reports that they have seem some burn into underlying layers of nitrocellulose lacquer. Wow!
I refinished our breakfast table with USL to test it's durability. I scratch-sanded the underlying polyurethane for adhesion, and sprayed a couple coats of USL. It seemed soft for the first week or so, but is wearing well - stay tuned.
Unfortunately Target Coatings are not available in your local big box or paint store. I started buying most of my Target from Jeff Jewitt (Homestead finishing) for two reasons... he had other things I needed, and if you are a customer you have access to Jeff (and Susan, his wife, partner, and co-author) for questions. Jeff doesn't carry all the Target products, so my last order was direct from Target - same price, same shipping cost, great service.
Good luck! Your comments and feedback are appreciated.
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