What do you use to thin water based paints to be sprayed with a airbrush. I have use alcohol in the past, but the last time I did I got some spotting in the paint when it dried. Also, what PSI do you spray at?
I have never had as good results with water soluable paints as I do with VOC based paints.
.
I have always had the "closest-to-acceptable" results using the manufacturer's own thinner and spray at 18-20 PSI. The airbsrush that has performed best with these paints was a Paasche Model "H" with the #5 tip. This is a metal single action external mix airbrush.
-Kevin
Living the dream.
This will probably start a flame war, but I just use distilled water. I've used it with PollyScale, ModelMasters, and CeramCoat craft paint which I use on buildings and for most weathering. You will get better atomization with VOC paints and thinners but I use water based so I can paint indoors without venting my spraybooth outside. I have found that alcohol can clump some paints, and some acrylics like Tamiya don't like to be thinned with water at all.
I generally try for the old "Like 2% milk" consistency. I typically use about 20-22psi. Sometimes, for small areas, like some rust overcoat on the side of a firebox, I'll dial the pressure down and significantly reduce the amount of paint coming from the airbrush to get a very small, light spray pattern.
My 2 cents,
George V.
I use distilled water with Pollyscale paints, but have not tried other brands. You should be aware that many water-based paints nowadays come pre-thinned and ready-to-spray...I guess the manufacturers figured that it would be difficult for modellers to find distilled water. More likely, though, is that there's more profit in a bottle of paint that contains less paint and more water.I use the water from my dehumidifier, and it's also useful for decal work, too. If you don't have a dehumidifier, distilled water is available in any supermarket, and a gallon of it is cheap and will thin dozens of bottles of non-pre-thinned paint (if you can still find such paint).
Wayne
What brand of paint are you (the OP) using? For some water based paints i am using simple tap water, but in general i am trying not to use them in my airbrush.
RR_Mel I’ve had the best results using Tamiya Acrylic X-20A Thinner. It’s a bit pricy but it works very good. A finished rolling stock paint job using the X-20A is equal to Floquil. Water works OK on structures, bridges and trestles.
Guy
Modeling CNR in the 50's
I am going to be using the Model Master paint. I usually like to use Scalecoat II or other thinner based paint, but I am building some A-line thrall cars for a friend and he wants some of them in Boxcar red. Walthers was out of this in the Scalecoat brand so I subed the Model Master paint. Maybe I should try and find another vender that has this in a thinner based brand.
I have not found a water soluable "Boxcar Red" that matches Scalecoat II "Boxcar Red #1". All the water soluable boxcar red, iron oxide red, red primer, mineral red, etc have a pastel appearance to my eye.
anthony61I am going to be using the Model Master paint.
For that 80/20 mix of water - 70% alcohol
Paint/thinner 3/2; 3/1 is said to produce a flatter paint.
In my area tap water works fine.
Henry
COB Potomac & Northern
Shenandoah Valley
I have been using Micromark paint and thinning with windex.
A gallon of distilled water goes a long way.
I also use Testors Universal Acrylic Thinner, or Liquitex or Golden Airbrush Medium, which are combination extenders and flow aids that help to toughen the paint finish while allowing it to spray cleanly without gunging up the airbrush tip.
You'll have to experiment to find the right PSI. I use a Badger 200 with a medium crown tip and set the line pressure at about 25 psi when it's damp here (8 months of the year). For highly-thinned "dust & grime" coats, I might go to 30.
Unfortunately i haven't used Model Master Acrylics yet so i cannot help you here. I ve only used the enamels in the past.
For the Gunze and Tamiya acrylics that i mostly use, i use a similar to windex product, and sometimes Tamiya lacquer thinner (for clear coats and glosses).
With respect to thinner/paint ratios, depends on airbrush and distance to object as well as desired minimum spraying pattern. If i want to cover a large area i will thin less than if i want to achieve tight demarkation lines or if i want to do complex patterns that require a narrow spraying pattern.