It always looks and sounds so easy, but it ain’t, at least it wasn’t for me.
For my first try I used Poly Scale Model Railroad Paint and Polyscale Airbrush Thinner. I have an Iawata Eclipse HP-BCS and a Paache H. I set a land speed record for clogging both brushes up. Took an entire afternoon (yesterday) to clean the brushes.
Today, I was a little more careful. I strained the paint and used a filter in the jar. I got spattering so I added some more thinner. Still spattered so I added a bit more thinner and noticed that the paint in the jar was beginning to coagulate. No matter how much I stirred by hand, the paint remained thick and globbed-up. I threw that batch out and began again after thoroughly cleaning my Paache airbrus again. Boy is clean-up fun. Not like a quick rinse of a brush.
I finally was able to get decent results with the Paache when I used denatured alcohol as the thinner but it still seemed like I had to go to about 40% thinner to get the job done.
My two questions are: how come the Poly Scale thinner had the effect it did on the acrylic paint and does it seem right that I need as much denatured alcohol as a thinner as I did?
Any advice would really be appreciated. Thanks. …Tom
I was using 25 PSI and the paint, although about a year old was from a brand newly opened bottole.
Ohmygosh, I never would have thought there was a difference. You’re saying that the two don’t go together. But, the Airbrush thinner bottle says, “For airbrush Application of Polly S Water Base Acrylic Colors.” The paint jar says, “Polly Scale Model Railroad Colors - Water Base,” and the Testors website lists the paint as Acrylic. I bet you’re right though cause mixing the two leaves a mess. I’ve left a question at the Testors website. I’ll be anxious to see what they say. Thanks for your help. …Tom
tom, i have never had success with but a few colors from poly scale or mm acryl paints. i switched to tamiya and have never experience clogging. i have to stop after about 5 or so minutes and clean away the tip dry. i recently had adhesion problems with tamiya, but its an isolated case. the only draw back is the color selection. i mix most of the colors. i’m currently brainstorming about building a “homemade” spray booth so i can use enamels as well. when i had success with polyscale or mm acryl paints, i usually thinned 50/50 with distilled water and strained the paint with womens pantyhose. hope this helps. later.
You can also use distilled water to thin. It won’t evaporate as fast as alcohol so might help a little. Tap water might have minerals disolved so it wouldn’t be a good choice for thinning.
Are you getting good results with 40% thinned paint? If so then you’ve found your solution. You don’t need to cover with one coat. The balance is getting the paint thin enough so it doesn’t clog the brush, but not too thin so it runs. You can then concentrate on getting consistent results from this as a starting point. The ratio of thinner to paint can vary by a lot.
As far as the Polly S airbrush thinner goes, it does seem strange that it is(still is) labeled for Polly S instead of Polly Scale. They are two different formulations, and the Polly S line has been discontinued. I use the Polly S airbrush thinner with Polly Scale paint without any problems. The Polly S thinner is probably very close to Windex or windshield cleaning fluid in composition so it should work for both line of paints. I’ve had Model Master Enamel do the same thing when adding model master airbrush thinner so it’s probably because the paint was starting to cure while sitting in the jar you mixed. I’ve found that adding thinner to paint really kills the storage life.
Other options are using acrylic retarders or flow aid agent to help with your clogging problems, but if you can get consistent results with your current approach then you don’t need to bother with this. Polly Scale has an excellent finish, large selection of well matched colors and binds to the plastic well, unlike Model Master Acryl.