Paint Thinner Selection

Yes.  For instance Testors airbrush thinner has been hard to get lately.  So I have learned to adapt by using good quality turpentine or mineral spirits.  Do not use something with the generic label of "paint thinner," as there is some real junk being sold with that title.

I have many friends that thin acrylic paints with isopropyl alcohol from drug stores, others with Windex.

No matter which, any time you are trying something different, going to a different thinner, etc.  test the mix with scrap plastic, not on a model, until you have confirmed it works.

Thank you

also, when you test on scrap plastic, don't use your best paint brush, or your airbrush

We read plenty about people gumming up their airbrush because they thinned paint with the wrong thing,,,,,,,,no sense having you join them.

You can test Acrylics and thinner compatibility in one of those cheap plastic artist's palettes from Wal Mart, etc.  Just put a couple of drops of paint in a dimple, add a couple of drops of "thinner",,,,and mix them up.  If they aren't right for each other, you will see them do things like separate out, or get gooey and stringy, etc.  Paints stick pretty badly to those, so you can wash them out and use them again.

Rex

But if you are mixing paint for airbrushing, how do you do the test without using an airbrush?

I guess I should have been more specific.  One of the reasons I test is to check how well the paint flows through the airbrush- how smoothly it goes down.  I have used thinner mixes that spit out gobs.  I find also that the thinning ratio is important- one mix/percentage does not necessarily work right if I change pressure or needle setting.  So I agree that there is a risk that airbrush cleaning may be a problem, but I think it is a risk worth taking.

I use 35mm film cans or similar, to mix paint 'off-brush' then let it sit for a bit...

If it separates, layers, or 'goops' don't put it in the a/b!

Edit: Google here:

You still have 35 mm film cans???  I used to throw them out by the dozens, but haven't seen one for many years!  I use medicine prescription bottles now, (no shortage of them in this house!)  but not for long term storage, just for mixing.  Also, the caps are good for mixing epoxy as well as paint samples.

yeah, right

push that mixture right on through the airbrush to find out if it gums up or not, because some guy on the internet says to

DON'T take the more conservative approach and test it in a shallow container first, just dive right in,,,,,,,,,,after all, you can then jump on a forum and tell about your gooped up airbrush and have the Same Guy tell you that "I knew those two products didn't work together in an airbrush"

TarnShip

push that mixture right on through the airbrush to find out if it gums up or not, because some guy on the internet says to

I've never been a fan of mixing paint in the brush. I always mix and thin in a metal measuring spoon before putting it in the bowl of the brush.  

There is a certain type of plastic measuring spoon that works well also. I don't know where to get them, I bought Anne a metal set and "liberated" the plastic ones from her.

the measuring "bowl" is shaped like an oval, and is very shallow,,,,,,,and the plastic repels paint like the polycone liners inside my paint jar lids,,,,,,,,,it almost beads up in the rush to get off the spoon. the spoons clip onto the measuring cups also,,,,,,giving you a sort of "spoon stand" as you mix the paint and thinner

I got the idea to use a film can for storing my media player headphones (earbud style) to keep them from getting all tangled when I carry them in a pocket.  I did manage to find an old one, but there was not enough room!  Oh well, guess I need another bright idea :-(

Maybe I can store mixed paint in them.

Mr. Stauffer is spot on correct, quality, name brand thinner/reducer is certainly useable for hobby paints, in MOST cases for me. I buy mine at either auto paint or quality paint stores, but often the cheapo stores like Wally World carry some very questionable stuff. One that I took home was called "Enamel Thinner," when I opened it at home it was like milk.

The most important consideration is, fully testing for compatibility with the paint and the PLASTIC as well. One called enamel thinner actually attacked and etched the plastic surface. Testing before hand will ensure a friendly relationship, with both the paint and surface to be painted. Nothing more disappointing than getting down to the later stages like painting, then seeing that you're trying to spray something like cottage cheese, or plastic eating acid. (Been there.)

Patrick