I got an email from a guy earlier this week about things people use to thin acrylics, and it got me thinking about acrylic additives in general and ways to make them work a little better.
From my point of view the two drawbacks with acrylics are: 1) Super fast drying time that causes roughness on the surface and drying on the airbrush tip; 2) Frequent lack of adhesion to bare styrene and the frequent necessity to prime the surface with enamel or laquer primer.
The email I got recommended Golden Airbrush Medium. According to the
Golden web site it is primarily for their fluid acrylics, but gentleman who sent me the email earlier said that he uses it with modeling acrylics so I gave it a try.
I sprayed a piece of styrene with MM Enamel (because I needed to check the color) and then when it cured I sprayed a section with PollyScale acrylic right frmo the bottle and an adjoining section with the same acrylic reduced 1:1 with Golden Airbrush Medium. The area that used the airbrush medium is MUCH smoother than the area without it, and at a 1:1 ratio it took several hours to dry to the touch so it certainly eliminates the drying problem. It sprayed a good bit smoother although it was a little on the thin side. I think 1:1 is a bit much though, and 2:1 would probably be better overall. The medium is white and it does cause a slight change of shade in the paint. Going 2:1 instead of 1:1 would probably eliminate a lot of that as well.
I didn't check the adhesion because the acrylic was sprayed over enamel. I'll spray a bare piece of styrene with acrylic with and without the airbrush medium this weekend and see if I can tell a difference.
Since I was in an experimental mood I took things one step further. I use Liquitex FlowAid in washes (thanks Swanny) to allow the wash to flow easier, so I started wondering what would happen if it was used in Future. I sprayed the hop half of my sample piece with a single coat of Future right from the bottle. The lower half was sprayed with a single coat of Future reduced 20% with Liquitex FloaAid. The half with the FlowAid is much smoother than the area without it and over a flat surface one coat was almost enough to wash or decal over whereas I usually have to spray two coats to get it smooth enough.
I haven't tried either of these techniques on a live model, but am going to do so. Admittedly this was a small test, but the results were good enough to make me want to give it a bit more of a workout and see what happens.