There's gotta be a better way . . .

Glad to read that alcohol did the trick for you, Frank.  It also makes a great paint stripper for the times something goes really wrong with painting a part and you just need to start over again.

I want to thank everyone who contributed to the solution of my airbrush situation. I've been doing a lot of painting this afternoon with no problems. I have an old Monogram F-101 VooDoo on the bench right now and there is quite a bit of painting to be done before assembly can begin. So I thinned Tamiya XF-7 Flat Red with 91% isopropyl alchohol 1-1/2 to 1, getting terrific results. No frustration. What a relief.

Brandon, I have the Atlantic to the east and the Gulf to the west, so high humidity here in the center of the state is a given.

I think one thing that gets overlooked more often than not is humidity. I use Tamiya in that brush with Mr color thinner and never ever have tip drying. I don't have it happen on any paint I use. I live in a dry enviroment where we see 20% humidity on a humid day. Most days are far lower than that. I think We need to take that into account when we paint. Just my 

BK

Thanks, everyone. I just know was at the paint bench and tried all three methods of thinning. In all three tries, thinner to paint was 1-1/2 to 1. All three worked out very well. No dried paint on the tip of my Sotar 20/20.

In order of preference: Tamiya X-20A, 91% isopropyl alchohol, generic lacquer thinner.

Tomorrow it's off to the LHS for a 8.5 oz. jug of X-20A.

Thanks, y'all, for your input. One of the kits I have on the bench right now is an Accurate Miniatures F-6B of the 111 Tactical Reconnaissance Squadron, possibly flown by Lt. Dean Gilmore. I'm sure the paint will be much better now that I know how to properly thin the paint. Thanks again.

I have used x20, lacquer thinner and isopropyl  alcohol to thin tamiya paint. I doubt thinner type is the issue,  but by all means, experiment. I've never had acrylic paint not dry on the tip. Constantly stopping and starting paint flow while keeping airflow going will do it every time... now if you are keeping the paint going, putting down a solid color, that's different.. thinning ratio might be off however,  as some have already suggested...

If you mean 1-1/2 parts paint to 1 part thinner then you very likely need to thin it more with the fine tip which I believe on the Sotar is right around a .2 tip.... I thin it more than that anyway even using a .5 or .7. Try 1 part paint to 1.25 thinner and see what you get that way on a test shoot. I bet it sprays great, might need an extra coat is all.

Echoing the replies above, I've almost always used Tamiya's X-20A thinner -- sometimes with a drop of their retarder added, if it's a long job or large quantity in the cup -- without any problem of tip-drying.

I've also used straight generic brand lacquer thinner on small jobs, again with no problem. (All through my Badger Anthem, my go-to AB.)

Eaglecash867

Have you tried thinning your Tamiya paint with isopropyl alcohol?  That's what I have been using, and I don't get tip dry issues.  I started off using 91%, but now I'm using 99% and everything works great.  I typically mix paint and alcohol in roughly a 1:1 ratio and shoot at 20 PSI.  That's with my Paasche H though, so your mileage may vary.  I had the same tip dry problems with Tamiya in the beginning, but it all went away when I switched over to alcohol.  You might give that a shot.

 

^^^ This is what I've been doing for 30 years.

cbaltrin

What size is nozzle opening on solar 20/20 frank?

 

The airbrush has a .2mm tip.

I am going to try all three of the tips from y'all. I have a small bottle of the X-20A thinner I use to clean paint brushes. And I have a bottle of 91% isopropyl achohol and hardware store lacquer thinner. I'll post the results later. Right now it's just too hot to be out on the patio to be painting.

What size is nozzle opening on solar 20/20 frank?

Have you tried thinning your Tamiya paint with isopropyl alcohol?  That's what I have been using, and I don't get tip dry issues.  I started off using 91%, but now I'm using 99% and everything works great.  I typically mix paint and alcohol in roughly a 1:1 ratio and shoot at 20 PSI.  That's with my Paasche H though, so your mileage may vary.  I had the same tip dry problems with Tamiya in the beginning, but it all went away when I switched over to alcohol.  You might give that a shot.

I spray my Tamiya acrylics thinned with hardware store lacquer thinner,absolutely no problems spraying.

I don't have a formula,I go by the skim milk look

Have you tried Tamiya X-20A thinner?  I use it with Tamiya paints, probably at around 1.5>1 and have never had a problem with tip dry.