Proper Temprature for airbrushing / Modelmaster water based Acrylic

The chemical cross-linking that occurs when a paint cures is temperature dependent. Acrylics tend to be more temperature sensitive than enamels. The lower the temperature, the longer the cure time. As a general rule, I would consider 55°F an absolute minimum for spraying, and I'd prefer somewhere in the lower 60s. Spray multiple light coats. You could also move the model up into the house after painting to help speed curing.

Two points:

1. Model Master Acryl paints do not need to be thinned for airbrushing.  The only exceptions are the skin tone paints and if you are doing fine line painting.
2. Testors does not recommend using Tamiya's thinner with their paints.  If you need to thin  Acryl paints, use Testors Acryl Thinner.

Some may disagree with what I say, but it is Testor's recommendations.

-Jesse

i had disastrous results using non Acryl thinner to reduce MM Acryl, took me all afternoon to get the stuff chiseled out of my AB.  Every bottle of MM Acryl I have ever opened has been on the thick side (maybe its all been dried up in the bottle?) except for a bottle of Jet Exhuast that is water thin. 

I would try to wait for a warmer day, or use a spraybooth and shoot in a room where you can heat the space.  A basement seems awfully cold and damp for painting....

David

PatlaborUnit1 wrote:

Every bottle of MM Acryl I have ever opened has been on the thick side (maybe its all been dried up in the bottle?) except for a bottle of Jet Exhuast that is water thin.

Interesting.  I've had no problems with any of MM Acryl paints.  All have sprayed just fine through my airbrush (Aztek A470).  Are you using the new formula Acryl paints or the old?

-Jesse

Painting never works in the cold.  The paint gets funny and the model gets cold and causes problems with adhesion.  At the very least, you could end up with the dreaded orange peel effect.

Best bet is to get a spray booth and paint in an interior room and vent out a window.  If you know how to use a screwdriver and socket wrench, you can get a spray booth on ebay for $220 shipped.  It's got a working area of 25wx17hx18d and comes with a 350cfm pole blower.  All you'll really need to add is light.  I added a battery powered 12" flourescent and it is more than sufficient.  I think the ebay seller is JCMfabrication.  He sells booths on there all the time.

-Fred

 

Testor's may well recommend against thinning their Acryl paints, but in my experience, I find that thinning is usually necessary.  I have also noticed that their paints seem to have a wide range in their out-of-the-bottle thickness which makes the concept of a specific thinning ratio is pointless.  Normally, paint should be thinned to the consistency of 2% milk. 

Although Testor's probably recommends against using non MM thinners with their Acryl paints, I use Tamiya thinner and have not had any problems, either when spraying or storage spoilage of the thinned paint.  I have stored MM acryls thinned for spraying with Tamiya thinner for litterally a couple of years without issue.

If you're stuck in a cold basement, perhaps a space heater or two could be used to warm things up a bit.  I paint in my garage in San Diego, and I've painted when the temperature is in the low sixties without problems.  When it dips into the fifties or forties, I have a couple of electric radiant space heaters that I use to warm up the area in and around my spray booth.