I’m sure that there are a few here who have a remaining stock of Model Master and Polly Scale Acrylics on hand and are running out of their proprietary thinner for airbrushing. I know I am. Have any of you found a substitute brand of thinner that works with those paints for airbrushing? I have used Model Master’s “Universal Acrylic Airbrush Thinner” to thin Vallejo Model Air, with no ill effects. Has anybody used Vallejo’s airbrush thinner with Model Master or Polly Scale acrylics? Or found some other brand of thinner to work as a good substitute?
I still have some MM enamels in my collection. So finding a few bottles of thinner is paramount. I think my last bottle of thinner came out of Hobby Lobby.
I’m looking for a MM substitute, too.
I just opened my last “squeeze” bottle of MM Acryl thinner.
The AK blue label “high compatibility thinner” kinda’ smells like the Model Master, but I haven’t been brave enough to try mixing any MM paint with it yet.
I’ve still got some enamel thinner. No ingredients listed in the can but I swear it smells like Ronson lighter fluid.
When I had Model Master Acryl and Polly Scale acrylics, and I had the whole range of both, I thinned them with cheap blue windshield washer fluid. No lie. Shoots smooth as silk, lays down nice and smooth, no tip dry and no fumes. Drop 2 bucks and give it a try. You’ll be glad you did.
4 Likes
I used to use the windshield washer stuff for thinning Polly S paints before Testors came out with the acrylic thinner. I’ll give that stuff a try again. Enamels are no worry, as lacquer thinner works quite well with those.
Thanks for the tip. If the washer fluid doesn’t work you can just use in in your car. 
I found this, but I haven’t purchased any yet;
I use other Golden Acrylics products, like retarder and gel medium, with Model Master paints without any issues, so I think this should work.
Well, washer solvent makes sense, it’s methyl alcohol and water. I’ll give it a try, thanks.
1 Like
Theoretically, the “blue”, cold temperature rated windshield washer fluid is 30% Methanol and 70% water, (preferably distilled). So says the DIY washer fluid pages on the internet. Right next to the article on grey Panthers and proper T-Rex colors. Other types are various mixture of Isopropyl Alcohol, Ammonium Hydroxide, (household ammonia) and Acetic Acid, (vinegar), which probably wouldn’t work as well.
1 Like
I couldn’t figure out how to fill a little squeeze bottle from a one gallon jug of washer solvent without making a horrible mess.
The big rapacious online retailer is sending me a bottle of the golden stuff to try out, thanks.
Hey don’t go grouping my cheap blue windshield washer thinner in with the likes of fairy tale grey Panthers and purple T-Rex. This stuff really works, and cheap. Buy the winter mix, it’s got distilled water, methanol, glycol, isopropyl alcohol, and detergent. It works magic on Acryl and Polly Scale, I used it for 20 years. If I’m lyin I’m dyin!
The blue windshield washer fluid works with Polly S & MM Acrylic as @SSGToms said. We had several folks in our local club use blue windshield washer fluid back in the day.
1 Like
Merely doubting the validity of the formula I was reading, (as I suspected there were other chemicals involved), not the utility of the blue washer fluid as an ersatz thinner itself, which I’ve known of for years. I’ve spent more than a decade in the chemical industry and studied plenty of chemistry in college, so I’m a bit leery when I see DIY formulas posted online. As for “Glycol”, is that Ethylene glycol, Polyethylene glycol, Diethylene glycol, Triethylene glycol, Propylene glycol, Ethylene glycol monoethyl ether? See my dilemma? For years, customers would call me, wanting to compound some obscure solution or product, using arcane recipes with incomplete, erroneous names and expecting me to provide them with the necessary chemicals. Hence my skepticism. I could write a book on these conversations. 
I’m conversant in archaic chemical language too, care for some Nitrous Spirits of Hartshorn, spirit of Mindererus or Liver of Sulfur? I used to need to translate such gibberish.
I do not own a copy of this book, but I have viewed it on occasion. I know it contains a section on paints, varnishes and adhesives, but the book is so old that it possibly pre-dates the advent of acrylic paint.
A search for home-brewed acrylic thinners brings up several videos, (including a mention of the beloved Blue Washer Fluid) and other formulas which are a bit more specific in their ingredients. Although rather long-winded, this video claims it’s recipe to be suitable for “all” major brands of acrylic modeling paints, including Model Master and Tamiya. 
(somewhat skeptical)
https://www.youtube.com/watch?v=VjJmRLifYik
If you don’t feel like spending 16 minutes of your time to get to the goods, the recipe is as follows.
200 ml of a 33% Isopropyl Alcohol (pure) / 67% distilled water mixture, (if using 70% IPA Rubbing Alcohol, do the math. (Ok, 94.4 ml of Rubbing Alcohol, if my calculations are correct)).
3 ml Acrylic Flow Improver (art supply store)
3 ml Acrylic Fluid Retarder (art supply store)
While the IPA / water mixture alone will thin your paints, the alcohol can start to break down the binders in the paint, hence the addition of the flow improver and the retarder. Your results may vary. Don’t shoot the messenger. 
1 Like
Amazon has Kindle version for 99¢
I’ve discovered that you can actually get Henley’s Book of Formulas for free, it’s so old as to be public domain. Unfortunately, the copyright is 1914, almost 40 years before the introduction of acrylic paints.
Thanks for the formula links. But I’m looking for an “off the shelf” option, and not for some do it yourself concoction. I’ll give the windshield wiper fluid another go, and try some Vallejo thinner just for the hell of it.
I popped for the 99$¢ version and yes it is very, very dated. There looks to be some solutions for non hobby related concocktions that might be handy though.
I use a couple of these home brew concoctions. I make a 1 pint jug of each. One for thinning and one for cleaning, and I’ve had good luck with all the acrylics I’ve used them with. Not Tamiya though…I only use lacquer thinner with Tamiya. Also when I’m done with ANY cleaning, I run a little lacquer thinner through the brush. I finish it off by spraying some Silicoil though as a lubricate before I put it away. I wipe down my airbrushes so they look like new before I put them away. Neat out,neat in. LOL