About a month ago I picked up a new bottle of Polly S Airbrush thinner at a LHS. I have used this many times for spraying Polly Scale paint and never had a problem. I prefer it over plain water for thinning because it seems to give a little better flow to the paint. I washed and dried a couple of shells and got ready to shoot some Polly Scale light gray undercoat on them. I strained some paint into my paint cup and added about 10% thinner and stirred well. Put the cup on the airbrush and proceed to spray. The paint flows for about 2 seconds and the tip plugs up. I figure I must have gotten a piece of lint in the tip when cleaning it. I take the tip off, clean it, start again. Same result, 2 seconds of paint then plugged tip. Well I think this is not normal, I better strain the paint again. I take the lid off the paint cup and to my surprise, the whole batch of paint is all clumps. Now I’m thinking that I must have contaminated the paint somehow. I usually try and keep separate jars, pipettes, strainers etc. one set for oil based paints and one for water base so that I don’t get any cross mixing, but figure I must have screwed up somewhere. I ditch the bad batch and proceed to mix up another. I watch closely and as soon as I add the thinner the paint starts to clump again. Now thoroughly confused as to what is happening, I give up for the day and decide to see if maybe someone else has had this problem. A quick net search brings up a few other complaints of this problem, but no one seems to have an explanation for it. Now that I know that it’s not just me I decide to contact Testors. I fill out their contact form on the web site and ask what may have gone wrong. A few days later I received the following reply: I sent the offending paint and thinner back, and today I received 2 bottles of paint and a note that the thinner was back ordered and will be sent later. Now I do have mixed feelings about this. On one hand, I appreciate that Testors stood behind their product and replaced it. On the other hand they are selling a product that they know has a defect.
Nelson The problem you are having with the clumping paint I also had several years ago. So to me this nothing new. It is sad that it has not been corrected. Because of the clumping I searched for other thinning agents and finally settled on blue windsheild washer fluid. I never had the clumping problem with Polly Scale paint again. I have since switched to craft paints and still use the bwwf. The main reasons I switched were that my LHS did not keep up his inventory and the price kept going up.
Nelson, Glad to know I'm not crazy!!! I had the same problem just a few weeks ago. I got so frustrated with the whole thing that I put away the airbrush, and said to heck with it. Thanks for getting to the bottom of this! Kevdog.
Nelson- My strong suggestion is to pick up a bottle of Liquitex Airbrush Thinner. It comes in all sizes and the larger the bottle, the cheaper the product. It blends really well as long as it is mixed thoroughly with a craft stick or some such. I have found that if the mixing is done in a 3 oz. bathroom cup, no straining is required. The same applies for the craft paints which require a bit more thinner and more mixing. It will also hold for a second coat up to 24 hours later with remixing since it will not evaporate at the same rate as water or alcohol.
With acrylic paint , Imho, the best ( and cheapest ) result is 2 parts of paint and 1 part of 70 % rubbing alcoohol ( I think it's isopropyhil alcoohol ). Of course, solvent based paints thinners are another story.
I use blue wwf, too. It does not affect the color as far as I can tell. I just mixed some flat white with bwwf and it worked just fine. I am also beginning to use the artist acrylic paints. I like them for N scale; they seem to work well. In the airbrush, the artist acrylic pigment seems a little more coarse than the Polly S paint. This is not a major factor in painting or paint colors. Artist acrylics do not have Espee Lark Dark Grey or MoPac Jenks Blue.
I use distilled water for over a year and never had any problems. For around a dollar a gallon, it is cheap as well and does not smell and does not add any harmful chemicals to the mix. I also never mix paint and distilled water in the airbrush cup. It is mixed in a bottle and the paint goes through a filter into the airbrush cup.
Oh boy, how to respond to this without sounding like a bitter ex-employee? I had the very same thing happen to me when I was doing a seminar in Bloomington. Somewhat enragged when I came into work that next Monday, I asked what gives. Explanation, the PH balence goes down in the paint due to ultralviolet radiation (eg Sunlight). I was told to add a drop or two of amonia to get the paint out of the cottage cheese look. Apparently no one has fixed the problem. What I do in the shop is just use a drop or two of water and low PSI and it works fine. I also use a lot of Modelflex now too.
I have to agree with Flash. I have not noticed any color differences with the bwwf. I too have used it with whites, light grays, and yellows with no problem. When I tried distilled water the paint had a chaulky look when it dried. That is why I continued looking until I found bwwf.
I noticed lately with a Badger 150 and a #3 needle and PSI set at about 16, I needed no thinner at all with Polly Scale. The Concistancy has gone down lately.
Hmmm, now I know I'm not crazy. Ruined my last bottle of Brunswick Green. I figured I had the wrong thinner!
One thing that I was told early on when I first got into Acrylic paints is using blue windsheild washer fluid and I have had very good results. BUT also was told to use the SUMMER formula NOT the winter formula since the winter had some antifreeze component that did not always play well with certain paints. PeteC
The big blue half or gallon jugs of Windex style window cleaner at the supermarket works well to clean the airbrush. To thin, I use Liquitex Airbrush Thinner. A few drops with the Pollyscale or a few more with the craft paints, well mixed, does the trick for me. Jim- 16 psi ?? really? I just kind of clog the works at such a low psi with the fine tip. You are referring to the one stripe tip, right? If you confirm the low pressure, I will give it another whorl, so to speak.
If your using a Badger 150 like I am, use the #3 needle and you can shoot PS at 16-18, I do it almost on a daily basis. The acrylics don't like the finer tips. Jim
First off, PolyScale and Poly S are two different animals. Poly S is Floquil's old water based paint that always had surface tension probs (beading up on a surface), the Poly S thinner was disigned for Poly S paints (I'm surprised the folks at Testors didn't mention that). The newer Acrylic Thinner is made specifically for PolyScale. I have been using an 80/20 mix of water/70% Isopropl Alcohol ever since I finished my original bottle of thinner, (10 years ago?), with excellent results over the years as a custom painter.
Clumping Paint The water based paints were a problem for me too. They dry in the airbrush and the clean up was a peoblem. I gave up on them for spray application and went back to Floquil and Scalecoat. I do use Model-flex for touch up and painting with a brush.
What do you mean by "they dry in the airbrush"? I have been using both Polyscale and Modelflex with both H and VL Paasche airbrushes for years and have never had this problem, unless I forgot to clean them after I was done. A lot of people didn't make adjustments to their tecnhique when switching from solvents to acrylics. You do have to turn up/increase the paint flow and use 20-30psi. Acrylics should go on a bit heavier than solvent paints as water has more volume than solvent thinners, but the H20 will evaporate and the paint will shrink down as it dries.
Put me down as someone who didn't trasition well from solvent based paint to acrylic. I have been painting Lexan RC car bodies as a business for almost 10 years now and never could handle using acrylics on them. Since back into model railroading, I am in love with acrylics, especially the PolyScale. The pigment is so much finer that anything else I have shot with and it covers so much better. The only time I have ever had issues with paint drying in the tip is when using the paint straight or mistakenly thining with straight alcohol. If I feel that the paint is coming out too dry, I will add a drop or two of straight water and that will cure it.
What an interesting thread to drag up. Hey, does anybody know if BNSF7173/Jim had a "Clinic" type thread here on painting with acrylics? He did in his blog, but it appears to not be working. He hasn't posted in some time as well. I'm especially curious, because he recommends some different methods for acrylics (hinted at above) then the common wisdom and I know others here have had success with his methods.
