Thinning Paint

[jaxenro]

Probably a idiotic question but does it matter when you thin paint? In other words does paint thinned 5 minutes before use act the same as paint thinned 5 days before use or is one or the other better for any reason? I am using nail polish with lacquer thinner

[Snake45]

I usually thin just before I paint. But not long ago I used (airbrushed) some Model Master Brit Green enamel that I thinned with lacquer thinner at least 8 and maybe more than 10 years ago. To my utter amazement, all I had to to was shake it up real good and it was as good to go as when I first thinned it. Most pleasant modeling surprise I'd had in years. 

On the other hand, I've learned that if you use naphtha as a thinner, your paint can start turning to Jello in as little as a couple days. And there's no bringing it back. It sure airbrushes nice while it's good, though! 

[Flat32]

What kind of paint were you thinning with naphtha and why were you using it?  Does it have some attribute "normal" thinners don't have?

[Snake45]

3 hours ago, Flat32 said:

What kind of paint were you thinning with naphtha and why were you using it?  Does it have some attribute "normal" thinners don't have?

Model Master enamels, and I like it for some jobs because it flows out better than lacquer thinner (dries slower) but dries slower than "paint thinners" so no running, and I can put two or three coats on at a time, same as I do with LT. If I lay it on just right, it looks almost like a factory car paint job--shiny but not "custom showcar glossy," with just a hint of scale orange peel. 

Only problem is the jelling. Oh, I used it to thin some hardware store Pactra Odds-N-Ends enamel once, and that model was sticky and smelled like paint for over a YEAR! It finally hardened, though, and polished right out. Never had that happen with Testors or MM. 

[Art Anderson]

On 8/4/2018 at 1:15 PM, jaxenro said:

Probably a idiotic question but does it matter when you thin paint? In other words does paint thinned 5 minutes before use act the same as paint thinned 5 days before use or is one or the other better for any reason? I am using nail polish with lacquer thinner

I use common ordinary lacquer thinner, from Walmart's paint department for all oil-based enamels, and of course lacquers, for airbrushing, and have for over 50 years, always with great results.

[Jon Haigwood]

With Createx (Auto Air, Wicked Colors) it is recommended that you wait 5 to 10 minutes before you use it.   

[dshue76]

For me, I base it on how thick the paint is to start with but generally all airbrush paints get mixed about 10 minutes before spraying. But if it's really thick before I thin it I like to give it some extra soak time. If it's supposed to be thinned for airbrush use or if I've mixed it for a prior use I'll add thinner to the airbrush cup as I test spray if needed.