Thinner question.

Your wife has a good question, and AJLafleche has a good answer.

Most of what is sold as "paint thinner" is mineral spirits, the nearly universal solvent for enamel type paints. The difference between what is labeled as "paint thinner" and what is labeled as "mineral spirits"—odorless or otherwise—is the degree of purity. Technically, paint thinner can have other solvents included in varying amounts. To be labeled as mineral spirits, there are limits on the amounts of other solvents that can be present.

For cleaning, paint thinner is all you need. For reducing (thinning for airbrushing) I prefer mineral spirits, as this almost completely eliminates any concern about paint-solvent compatibility. By the way: That expensive Testors thinner is probably mineral spirits. 

Deepsky wrote:

...why I was paying $3.16 for a one and a quarter oz. bottle when I could go to home depot and by thinner or mineral spirits to do the same thing for a tenth of the price.

Just to add to the chorus, I use the cheap Home Depot stuff (i.e Klean Strip Paint Thinner which if you read the fine print on the can is usually identified as being 100% mineral spirits) and it works just fine for ModelMaster enamels.  Semi-recently, I bought a jar of Model Master Airbrush Thinner, just as an experiment t see if there was some magical difference between the paint brand thinner and the generic stuff.

As far as I can tell, the Model Master brand smells identically to the cheap stuff, and I cannot detect any difference in how it reduces the paint for airbrushing, so when my bottle of Model Master Thinner is used up, I'll be going back to the chea stuff.

Andy

Deepsky wrote:

I just got my first airbrush and have not used it yet since the idea of wasting expensive model paint on cardboard isn't practical. Any ideas?

Expensive paint to practice on cardboard or a junker vs. expensive paint to practice on an expensive kit. It's one of those things you have to buckle down and do.

Ayep.

Many people recommend milk/windshield washer jugs as practice targets. I use/used trays like those in a cafeteria, which are very easy to clean up afterwards.

Don't use cardboard. It absorbs paint and you will not learn the proper application rate for impervious surfaces like plastic.

Deepsky wrote:

Now that I know about cheap thinner, how about a cheap way to practice airbrushing. I just got my first airbrush and have not used it yet since the idea of wasting expensive model paint on cardboard isn't practical. Any ideas?

If you just want to practice technique and control, buy a quart of latex house paint and start thinning it down, way down, with alcohol (NOT water) and have at it.   You may even find colors that you can actually use in quart cans.  I've found a number of even smaller cans (about 12 oz, I'd guess. They're just a skosh bigger than a Vienna sausage can) of paint as samples at lumber yards and hardware stores, Ace Hardware in particular... 

Another way is use tempera paint to practice, again, thin it with rubbing alcohol.  They come in nice 16 oz premixes for about 2 bucks each, and if you buy the primary colors of Red, Blue, Yellow, and also black and white, you can MAKE any shade you want in the secondary and tertiary color wheels...  I use temera almost exclusivley on diorama bases, ground work, even some kits.  Just gotta make sure you seal it with a good clear coat of something else, because tempera will wash off with water even after it's dry.