Dilution formula(s) for ModelMaster Acryl paints

I use thier MM Acrylic thinner...but I think that's only part of the issue. Have you tried reducing the air pressure or varying the distance you are spraying?

Vinnie is right on that... what pressure do you shoot paint at, and approximately how much paint to thinner do you use?  (everyone has their personal favorite although there is a general range to it) And lastly, what are you thinning with?  The MM acryl thinner Vinnie mentioned is great stuff, as is Tamiya acrylic thinner.  Some also use 91% isopropyl alcohol.

I would say I thin approximately 3:2 to 2:1 depending on what pressure and how close to the model I am spraying at. (thought I better explain that, 3:2 is thinner than the other and I shoot that at lower pressures for finer detail, 2:1 is more for general coverage and subsequent camo on top etc... that I shoot at higher pressures)

This is a good resource: 

http://www.craigcentral.com/models/pressure.asp

as is this:

http://www.craigcentral.com/models/thinning.asp

Most Model Master Acryl paints do not need to be thinned for airbrushing.  They are designed that way. This is from Testors FAQ's:

Question:	What is ACRYL?
Answer:	Testor has introduced a new formula of Model Master “Acryl” paints. This line of acrylic, water-based formula is certified non-toxic, non-flammable and has a very low VOC level. The paints dry fast and clean up easily. Model Master “Acryl” has fantastic leveling properties so brush strokes virtually disappear, and it doesn’t pull away from details. Once dry, the “Acryl” paints develop a hard, durable enamel-like finish, which is buffable, waxable, washable, and can be wet-sanded. This new paint features the most popular high gloss and flat finish colors from the Model Master enamel line. All colors, except Figure Model Paints which feature thicker viscosity for better brushing, are airbrushable directly from the bottle-no thinning necessary (some flats may need thinning when spraying fine lines). All paints are packaged in 1/2oz. bottles. The entire line of Model Master Acryl paints has been proven effective through extensive testing by both novices and pros for over a year.

 

usmc1371 wrote:

Most Model Master Acryl paints do not need to be thinned for airbrushing.  They are designed that way.

Thinning (paint viscosity) is an important variable when airbrushing. I would not rely on Testors marketing department for guidance. If you want to spray a FINE line...you will need to thin those bad boys.

All paints can be airbrushed without thinning.  All you need is enough pressure.  If you want to be able to CONTROL what the spray does you will most likely need to thin most of them.  I have had good luck airbrushing MM Acryl right from the bottle, depending on the bottle.  If it's new it works fine.  If it's been sitting around a few months and been opened and closed and opened and closed a few times it starts to thicken.

The bottom line is that there is NO single, cut-and-dried answer to the "How Much Do I Thin" question.  The (admittedly ambiguous) answer is you thin as much as is necessary.  IF the paint won't spray properly AT THE PRESSURE THAT YOU WANT TO USE then it needs to be thinned.  If it sprays at the pressure you want to use then it doesn't need to be thinned.  Since this question comes up about once a month I wrote a page about it on my web site.  Here Is The Link