Ratio of Paint / Thinners for airbrush??

I generally start at about half paint, half thinner (more properly, reducer). In spite of what you may hear, the best advice I ever got was: "About the consistency of 2% milk." After measuring with scientific precision for several years, I have come to the conclusion that this advice is, indeed, the best.

However, when you are starting out, I do advise careful measuring. It is easier to keep track of what you are doing, (you really do have a 50/50 mix at the start and not 60/40, for example) and helps you remember what you did.

And don't forget that variations in paint viscosity call for slight adjustments to air pressure and distance. 

I thought we were all talking about Tamiya Acrylics?

I'm not saying you're wrong, only pointing out that starting off with a higher paint to thinner ratio allows you to add more thinner to correct the consistency, than having to add paint. Since paint is the more expensive of the two, I prefer my method. I probably end up with the same ratio as you do, I just take a more circuitous route. Truth be told, I'm not so concerned with measuring, and tend to "eyeball" the mixes. So far I haven't had any batch to batch color issues.

Gee guys, you make it sound so easy.

Maybe I have been to technical in my mixing proceedure? 

1. Figure out roughly how much I'll need for spraying (guesstimate).
2. Pour half of what's needed of paint.
3. Pour slightly less than half of thinner.
4. Stir with toothpick, watch the drip.
5. Add drops of thinner until drips look correct.
6. Pour paint mixture into AB and blast away.

Now you tell me all I have to do is go out, buy 2% milk and compare the flow? Dang!

Not meaning to take over this thread, but if I still have your attention Bill...

I haven't yet tried acrylics for my car models.
The proceedure I'm used to following "after" the paint cures is -

• Wet sand with progressively finer grits if needed (smooth out orange peel, dust, etc...).
• Buff out the fine sanding marks with Meguirs Sratch X (almost like toothpaste).
• Few coats of Meguirs Gold paste wax.

Can a similar proceedure be done with acrylics?
Would I have to change products?

I have only seen a few cars in person sprayed with bright colored acrylics and it didn't seem to have that deep luster like you would have on a real car. Would that depend on the color and/or brand of paint?

Bill, that's odd about the differing thinning ratios for Tamiya acrylics—I always end up around or slightly above 50/50 . Go figure.

Jim, as far as the acrylics are concerned, you may have trouble with your process. Acrylic polymers generally are softer than those used in enamels. I can't speak from experience with cars, although some of the folks in the local chapter use acrylics with great success.

I have used the paint polishing kits to polish fully cured Tamiya acrylics and PollyScale acrylics, which held up very well. This was basically an experiment aimed at the answer to  your question. I suspect that surface prep and curing are, as usual, critical to acrylics in this respect. 

jhande wrote:

Gee guys, you make it sound so easy. Maybe I have been to technical in my mixing proceedure?  Figure out roughly how much I'll need for spraying (guesstimate). Pour half of what's needed of paint. Pour slightly less than half of thinner. Stir with toothpick, watch the drip. Add drops of thinner until drips look correct. Pour paint mixture into AB and blast away. Now you tell me all I have to do is go out, buy 2% milk and compare the flow? Dang!

As an old lab rat, I learned to listen to the guys on the floor with the practical experience—as a result, I was the lab rat they would listen to. Paint technology is a compatible mixture of art and science—sometimes you just have to grind the mixture a little longer…

You're like "Old Micrometer Fingers" our senior lab tech. Anything he had to say was worth thinking about.

Triarius wrote:

Bill, that's odd about the differing thinning ratios for Tamiya acrylics—I always end up around or slightly above 50/50 . Go figure.

Well, I might be doing it all wrong, too! This is just my observation, and YMMV. 

Thanks guys for the input.

Not that I perform the lacquer color sanding technique on all my enamel paint jobs Bill. Only the ones that need saving in spots, beats stripping.

LOL Ross, I just got so used to watching the paint drip off the stirring stick. That's how I knew it was ready for spraying. I'm following suit with my AB now too. What's that saying about old dogs or old habits...  

jhande wrote:

What's that saying about old dogs or old habits...

"Don't mess with the Voice of Experience!"

Triarius wrote:

"Don't mess with the Voice of Experience!"

I like that one better...