Painting with Fingernail Polish
By: Duane Drew
With regards to thinning nail polish, I'll run through the procedure I use when I shoot it. I've shot a lot of finger nail polish over the years and have used polish from Revlon all the way down to the el-cheapo Wet'N'Wild. I have used automotive lacquer thinners exclusively to thin it. There are a couple of variables that come into play with it though. I don't recommend using a hardware store quality lacquer thinner for only one reason, control. Where you live, the climate and the reducer you use have EVERYTHING to do with successfully shooting any lacquer product. If you go to an automotive paint store you can usually pick up a pint can of lacquer thinner. It is more expensive than say Ace Hardware or Wally World, but as they say, you get what you pay for. Lacquer thinners have different ratings of evaporation for use in different climate situations, i.e. the warmer and less humid it is, the slower the thinner you want to use. Lacquer thinners have a very low flash point, so if you use too "fast" of a thinner the paint will actually begin to dry while atomized in the distance between the tip of the airbrush and the piece you're painting. Too much air pressure will also cause it to do the same thing. I set my compressor at 21- 22 PSI for lacquer pigmented paint. When you go to the paint store, ask the person behind the counter what thinner they recommend for the current atmospheric conditions. If it is someone who you do not trust to be an expert, the cans are marked with the temp ranges so you can just take a little extra time and read over the labels. This is actually a good lesson in painting, as every aspect of preparation is important to learn, and it's kind of fun to learn it. At least I thought it was, but I'm easily amused. LOL
While you're at the paint store also pickup a cheap plastic in-line filter. They are about $4.00 for 2, I think. They are a life saver for humid conditions.
Lacquers are so much easier to shoot than enamels for many reasons, Drying time being the biggest benefit and it isn't as "thick" as enamel.
I also use about a 50/50 ratio for thinning. It isn't real critical because lacquer is very forgiving. Use a separate jar to mix your paint(polish) in. Pour in your pigment first and then add thinner. Don't pour all of your paint in at once in case you get it a little too thin. If you're doing a single color paint job, open the mixture ratio on the brush up and let it flow out in a larger pattern that what you're used to with enamels. Because it flashes so much faster you can apply more paint at a slower speed with less chance of runs or pulls. The first coat should be a tack coat. Shoot the entire area you're painting with a light - medium coat, pretty much just like you would with enamel. You don't have to let it tack up as long as you do with enamels before you start with the heavier coats. If you wait more than 7 - 8 minutes the tack effect is virtually lost with lacquers. For the color coats, set the pattern to about the size of a quarter when you're holding the brush 8 - 10 inches away from the surface. If you get any further away, the paint starts to dry before it reaches the surface and will cause the paint to look powdery or flat. A lot of times, with finger nail polish you need to open the orifice up because of the flake size anyhow. Start the paint flow about an inch behind your starting point and then start moving. I'm right handed, so I move from right to left, pushing the paint puddle and blowing any dust or lint off the surface before the paint gets to that area. Move slow enough so that you see a shiny wet spot about the size of a quarter and try to keep it round in appearance. If it starts to get teardrop shaped you're moving a little too fast. Personally, I like to start at the bottom and overlap my passes slightly as I move up the body to the top of the door line. Don't go to the center of the roof, especially with any kind of metallic or pearl. You want to do each section at the same time. Passenger side, bottom to top then driver's side bottom to top and then do the top of the hood, roof and trunk together. You get a natural shadow line where the transition between the vertical and horizontal surfaces meet anyhow so the blend isn't as critical. Pick up a couple of extra cheap bottles of polish and let him play around with the speed and pattern on a spare body. Let him create a run or sag so he can learn how easy it is to fix these when using lacquer. If you get a run, calm down and just leave the body overnight, and don't worry. After 15 -18 hours, depending on conditions, you can take a piece of 600 grit wet sandpaper and sand the area lightly under a light stream of water and the run will disappear in minutes and you can feather it into the rest of the area. If you're shooting metallic or pearls, you'll be better off sanding the area smooth and repriming and starting over - otherwise it's extremely difficult to get the paint to blend into itself without noticing a shade difference. I use PlastiKote sandable automotive primers and I match my primer color to the paint color. Dark blues, purples: black primer. Reds, browns, dark orange = Red Oxide primer. Medium blues, silvers, grays = Gray primer. Yellow, white, green, light colors = white primer. The PlastiKote primer has proven to be the best when shooting nail polish, in my opinion.
Lastly, but probably most importantly, you will need to spend the extra money and get the right kind of respirator. Don't use a paper dust mask, no matter how well ventilated the area is. The lacquer/thinner is very small in microns when atomized and it will not be filtered by a cheap paper mask and can really cause some serious long term health problems if the proper safety equipment is not used. You can normally get a good one with replaceable canisters for about $20 - $30. Never shoot it in a confined area where an open winding electric motor like that on a fridge may start up or use an exhaust fan with brushes when the room is filled with the fog. It can cause a flash explosion. Wear rubber gloves when mixing the paint and cleaning the brush so the solvents don't penetrate your skin and wear safety glasses, or better yet, goggles because the solvents penetrate through the surface of the eyeball much easier than through the lungs or skin.
When/if you choose to clear coat it you have a couple of options. Before I broke down and bought a quart of automotive clear lacquer (DuPont 380S) I shot everything with PlastiKote Clear in the rattle can. Just set it in a sink of hot water for 10 -15 minutes and shake it real well and it flows very nicely. I know other's use Krylon Krystal Clear, but personally I think it's life span before starting to yellow after being applied is short and I just don't like it. If you decide to purchase some clear, you thin it a little bit more than you do the paint, about 65% reducer, 35% clear and shoot it wet.
I hope this helps. Good Luck.