Model Master Acryl Thinning for Airbrushing.

Want to post a reply to this topic?
Login or register for an acount to join our online community today!

Model Master Acryl Thinning for Airbrushing.

  • OK, before I get flamed, I did a search on this very topic on these forums, went to the Testor's website, searched Armorama and ARC forums and I get different answers from everywhere.

    Do MM Acryl paints need to be thinned prior to airbrushing?  I just tried to shoot some RLM 78 on a 1/72 Bf-109E4 Trop using my "normal Tamiya" 1:1 ratio, even used the Testor's proprietary thinner, and it was like shooting water out of my AB (an Iwata HP-CS) and I ended up with clumpy crap in the cup.  This was a brand new bottle that I mixed with the little battery powered Badger paint mixer.  


    I sprayed a primer coat last night with the same AB with Tamiya XF-19 and X-20a and had no issues.

    These very forums said :

    2007 No they don't need thinning (referenced a post that has been deleted)

    2008 Yes, they should be thinned

    2009 They are able to be airbrushed straight out of the bottle.

    Testors FAQ: 


    Most Model Master and Testor "Acrylic" paints are pre-thinned for airbrushing. Thin paint by adding thinner drop by drop, until your consistency has been achieved. 

    Air pressure should be approximately 18-20 PSI. 

    Acrylics will dry to the touch in minutes; they require 24 hours for a full cure.

    I really do try to not be an idiot, but I swear, this is driving me bonkers.  Should I just add the paint into my mixing jar, take a little up in an eyedropper against the glass, and see if it has that "2% milk" look to it, and go from there?


    Any help would be appreciated... my little 109 has a spot on my shelf just waiting for it, and I don't want it to be homeless much longer.


    Matt - IPMS #46275

    "Build what ya love and love what ya build..."

    Build Logs, Rants and Humor



    Replies to this thread are ordered from "oldest to newest".   To reverse this order, click here.
    To learn about more about sorting options, visit our FAQ page.
  • I'm no expert, but I use MM Acryl all the time and I just shoot it straight from the bottle. Granted I use an Aztec dbl action gun with an acryl tip, but I haven't had any trouble except for some gloss colors. I never did get the gloss colors to throw quite right, but no trouble with the flat colors right out of the bottle.


  • Try it straight from the bottle and thin as needed.

    Some colors are already thin enough and others need a little thinning in my experience.  Wink





  • I get the best results by adding a few drops of Future into the paint cup and stirring it in before I spray. 


  • Sigh...

    OK, when I do things like this, I wonder how I actually remember to breathe sometimes.

    If you've ever seen Testor's Airbrush CLEANER and Testor's Airbrush THINNER, they are in the EXACT same bottles, which, of course I wasn't paying attention to.  I had used all my thinner, and filled it with distilled water for some Vallejo paints, and thought "Oh I'll just grab that other full bottle of thinner from my hobby closet."

    This bottle, was the CLEANER, which I was merrily attempting to use as THINNER for my Poly Scale and MM Acryl paints.

    So thanks to y'all for answering my questions, next time I should just RFTB before I start dumping stuff in my mixing bottles.

    And yes, I really WAS paying attention to the bottle, it just never registered from my eyes to my brain.  

    Matt - IPMS #46275

    "Build what ya love and love what ya build..."

    Build Logs, Rants and Humor



  • Lol! I have the same 2 bottles sitting on shelf, and everytime I pick one up and think that it would have been easy to pick up the wrong one.

  • I have yet to pop open a new color of acryl that doesn't need thinning. I believe that even Testor's statement about being pre-thinned is misleading and confusing for some 1st timers (myself included). In my experience with Acryl (which dates back a few years), they all need to be thinned down. I use their native Thinner (# 50496) or alcohol.

  • I'm not a great fan of Acryl, but this is something I've tried with success with Polly Scale acrylic railroad paints which I believe are made by the same company. Get some "Flow Aid" and "Fluid Retarder" from any art supply store. These are staples in acrylic painting and are used to get a smoother flow and a slower one. Flow aid is made to be cut at least 10:1 with distilled water so I think functions a little like detergent that some people use. (I wouldn't dismiss the advise to try Future either.) Problems with paints often have something to do with the suspension of the pigments in whatever solvent is used. Anything that will keep the pigments from settling will help prevent tip clogging and give a more even flow. Anyway get some of this stuff and try thinning your paint with maybe 85:15 paint/thinner. BTW - this combination when used with Tamiya turns it into a pretty fair paint for hand brushing. I don't know what solvent Tamiya uses but for airbrushing it takes to lacquer thinner like trumps. Some flow aid and retarder slows the very fast drying and allows perfectly respectable hand brushing.


  • CallSignOWL

    I get the best results by adding a few drops of Future into the paint cup and stirring it in before I spray. 

    That's odd. Why add Future which is a gloss coat to a flat paint?





  • It wont gloss it up very much if you only use a few drops to help the spaying. IF you add a larger fraction, then yes, it begins to gloss up the paint. Either way, people apply a sealing coat on top of the paint and decals that should take care of any shine it would give you. I even add a couple drops to my MM acryl flat just to help the paint flow. I have had little problems with it glossing up the flat coats.


  • That is interesting. I have never tried any Future added as a thinner although I don't use Acryl any longer as I think Tamiya is much better paint in every way. Wink





  • Future:

    1. The reason it helps flow is that it helps keep pigments suspended: I'm sure that's what Tamiya's solvent does (something like Flow Aid mixed in with ISA I'd betcha) - having alcohol in it makes it dry fast which is good or bad depending. Can't pontificate about Acryl, but Polly Scale has very fine pigments (makes for a great paint in my view) - when you wash it off your hands, something like lacquer thinner is nice to have around. If Acryl is at all the same and its solvent is mostly water, then future will slow the pigments settling to the bottom of the air cup and keep it more evening distributed. That's good. Not sure about others, but when I have clogged air brushes it's either because I've let some bit of matter get into the nozzle (stupidity) or because I've been doing a lot of fine work without cleaning the tip - in other words, working for several minutes and giving the paint time to dry in the nozzle. So keeping the pigments suspended and slowing the drying will both help - but also slow drying a bit on the kit.  (Obviously for hand painting, this can be an advantage.) I'd like a chemists view on this, but I'd bet that the reason Vallejo brushes so well is that the pigments are very fine and stay suspended well in it's solvent which I believe is mostly water.

    2. Future will gloss a finish only slightly and only if done at high concentration. Not sure why Phil Foley's (Promodeller guru) observation on Klear (UK word for Future) isn't holy writ. If you spray future on your kit straight at the end you end up with a satin finish. Indeed, put in about 1 part of "flat base" to 3 parts Future and you've got a pretty good dull coat - and no risks of real Dullcoate eating your model.  If you want a gloss finish hand paint future - then it will shine. It's very easy to do and if you don't glop it on you won't see a brush stroke because the stuff is self-leveling. This is why folks dip their cockpits into a jar of Future or paint it on: wouldn't look at all the same if you airbrushed it. Foley did a double build on a P-51/P-47 to show a natural finish done with acrylics and Alclad. With the acrylics he painted on a couple coats of Future at the end. I did the same on a Ki-84 and the result is terrific. That said, I'm not really sure how often a true "flat" is a desirable coat for how many models. (Not really sure about a real shinny gloss either.) I think especially for aircraft that a dull satin is better.