Paint to Thinner Ratio @ what PSI


michael lambert
01-18-2008, 03:53 PM
Hey guys,

So i got my new airbrush and i am looking to get going on using it.

What have most found to be the best mix for Tamiya paints and thinner and spraying at what PSI?

stevenoble
01-18-2008, 04:44 PM
Hey guys,

So i got my new airbrush and i am looking to get going on using it.

What have most found to be the best mix for Tamiya paints and thinner and spraying at what PSI?

I usually mix 50:50 paint to thinner or 60:40 paint to thinner.Pressure's between 15-30 Psi,but experiment a little with your own airbrush.This setup works well for me with my airbrush but it may be different with yours.

MPWR
01-18-2008, 08:49 PM
Here are the real world rules of thumbs I paint by:

-Paint with the lowest pressure possible. Reduce the pressure until just before the airbrush stops spraying smoothly- thats the pressure you want to spray at.

-Use as much thinner/reducer as you can before the paint runs/pools. Thin it until just before it pools (and spray it on in light mist coats to avoid pooling)- this is the amount of thinner you want to use.

These can be judged only by test spraying- you MUST test spray. There are far to many variables in airbrushing (ambient temperature, humidity, operator skill, phase of the moon, etc) to expect that thinning by a ratio will work. You must find your own pressure and your own level of thinning by testing and experience.

...and that pressure will probably be between 20 and 30 psi for Tamiya acrylics, and you might have decent luck with oneish part thinner to twoish parts paint. Or so. But test it (always test it) and find out for yourself.

Adam Baker
01-18-2008, 09:56 PM
Ive only been airbrushing Tamiya paints for a very short time. Before that, I used almost exclusively Model Master enamels.

Ive been using 91% Isopropyl Alcohol to thin my Tamiya paints. Some people agree w/ this, and others vehemently disagree w/ it. So far Ive had good results w/ it, so until I have otherwise, thats what I'll continue to use.

I started by mixing them 50/50 w/ the Alcohol, and had very inconsistent results. Sometimes would have great results, other times had nothing but trouble.

A very good friend of mine is the owner of the local hobby shop. I was talking to him a few weeks ago about the problems I was having w/ painting my current project (Tamiya Ducati 916). I was trying to airbrush a couple metallic colors, and it just wasnt going well at all. Spitting, very rough texture, etc. I had been thinning it 50% w/ the 91% Iso. He told me, that w/ acrylics, that you want to thin them as little as possible, and still have it thin enough to go through the airbrush. He suggested 70/30 or 75/25, paint to thinner. I went back, and thinned it about 70/30, wasnt extremely precise on it, and it sprayed a lot better.

So it really all comes down to trial & error, like mentioned before.

MPWR
01-18-2008, 10:34 PM
Ive been using 91% Isopropyl Alcohol to thin my Tamiya paints. Some people agree w/ this, and others vehemently disagree w/ it. So far Ive had good results w/ it, so until I have otherwise, thats what I'll continue to use.

A very good friend of mine is the owner of the local hobby shop. I was talking to him a few weeks ago about the problems I was having w/ painting my current project (Tamiya Ducati 916). I was trying to airbrush a couple metallic colors, and it just wasnt going well at all. Spitting, very rough texture, etc.

The spitting and texture problems you were having were almost definitely because of thinning with 91% iso. Isopropyl alcohol will certainly disolve Tamiya acrylics just fine- but it evaporates MUCH TOO FAST to use it as a thinner. It spits and textures because the alcohol is evaporating out of the spray stream, and the paint is hitting the surface already partially dried. This can be a nice technique of building up a grainy surface texture (like to simulate the rough 'crackle' surface Ferrari sometimes uses on cylinder heads), but it's a terrible way to try to get a good smooth finish.

Thinning acrylics with water/alcohol is very popular with military aircraft and armor modelers, and honestly it works fine- as long as you're goal is a flat 'military' finish. But it performs poorly if you're using gloss colors. Here, your much better off using the manufacturer's thinner. Yes, it's more expensive- but honestly, isn't a nice finish on your parts worth the $0.12 that the proper thinner would cost? Obviously you don't have to clean up with Tamiya thinner afterwards, but try it for thinning the paint. You'll be amazed at the difference it makes.

Sixx
01-18-2008, 11:46 PM
so basically, if I'm using decanted Tamiya spray paints, then thin it with Tamiya thinners? What about MCW automotive paints? I just had a problem with my brand new airbrush spitting, and before I started painting, I completely broke it down and cleaned it.
I am using Nason thinner for all of my paints right now and I have had some problems! any suggestions?

Adam Baker
01-19-2008, 01:54 AM
THe next time I get to my LHS Im going to go ahead & try the tamiya thinner. Is it possible to get it in anything larger than the 1/3 oz container? Thats all my LHS has it in.

MPWR
01-19-2008, 09:13 AM
Is it possible to get it in anything larger than the 1/3 oz container? Thats all my LHS has it in.

Definitely.

http://www.hobbylinc.com/gr/tam/tam81040.jpg

The little 1/3oz bottles are really rather silly. :grinno: I go through an 8oz bottle in a year or two. They can be found pretty easily online, but your LHS should be able to order larger sizes for you. You may have to give them the specific stock number for the 8oz (if they're lazy), but that's easy enough to find online, too. :wink:

so basically, if I'm using decanted Tamiya spray paints, then thin it with Tamiya thinners?

Absolutely. If you're spraying decanted TS lacquers, get a bottle of Tamiya lacquer thinner to thin them with. Tamiya lacquers are a rather unique formulation, and there's not alot else that work well with them (Mr Color thinners are probably the only real exception).

http://www.tamiyausa.com/images/product/631/87077/header_87077.jpg

What about MCW automotive paints? I just had a problem with my brand new airbrush spitting, and before I started painting, I completely broke it down and cleaned it.

I'm not sure what MCW's formulation is- I believe it's automotive laquer, in which case use a good quality lacquer reducer like PPG or DuPont. My very favorite is PPG DTL105- you'll probably have to order it online or buy it from an auto paint shop. It's truly amazing what properly thinned auto lacquer will do, and it's definitely worth thinning it with the right stuff!

Ask MCW what their recommended thinner is, and find some.

Sixx
01-19-2008, 10:16 AM
I had no idea that the thinner we use really makes that much of difference! Thanks for the great advice MPWR. I ordered some Tamiya laquer thinner online and will call MCW to see what they say!

Adam Baker
01-19-2008, 11:40 AM
Thanks MPWR. I figured there were larger containers, but I dont think my LHS has anything but the 1/3 oz bottles. The Tamiya site lists it for 7.50 a bottle, which isnt nearly as expensive as I expected it to be, so I'll have my LHS order me a bottle.

MPWR
01-19-2008, 11:40 AM
I had no idea that the thinner we use really makes that much of difference!

It's true. :grinyes: Full chemical compatibility is a beautiful thing with paints and thinners.

It's possible to get good results sometimes with stuff other than what the manufacturer recommends (and some people really get a kick out of using the cheapest possible thinner that can be made to work :dunno: )- but don't mess with other stuff until you've tried the manufacturer's intended thinner for a while first. :disappoin That way, you will know how the paint is really supposed to behave ideally, and you have that base of comparison to judge the paint's performance if you're messing with other formulations.

Adam Baker
01-19-2008, 01:22 PM
Well, went to my LHS, and as I expected, they only had the 1/3 oz bottles. So I had them order me the big 250 ml bottle.

Its no comparison. 2 bucks for the 1/3 oz (10 ml I htink) and should be around 8 dollars for the 250 ml bottle. Might go ahead & order one off the net, but probably take about the same time to get it as my LHS to get it.

Sixx
01-19-2008, 01:38 PM
After reading the great advice from MPWR, I ordered two bottles from tamiya.com

your right, no comparison! i can't wait to get it and get spraying!

Adam Baker
01-19-2008, 02:51 PM
Well, I think Im going to wait & let my LHS order it, that way I dont have to worry about shipping. W/ shipping it looks like it'll cost me about 12-14 dollars, but if I wait for my LHS then it shoudlnt be more than 8.

Didymus
01-19-2008, 11:50 PM
so basically, if I'm using decanted Tamiya spray paints, then thin it with Tamiya thinners? What about MCW automotive paints? I just had a problem with my brand new airbrush spitting, and before I started painting, I completely broke it down and cleaned it.

I think it's crucial to use Tamiya thinner with Tamiya acrylic paints, mostly because it retards drying. That allows the paint to level before it gets dry. But their spray-can paints are synthetic lacquers, and hardware store lacquer thinner works just fine with them.

Spitting is usually caused by insufficiently thinned paint.

I am using Nason thinner for all of my paints right now and I have had some problems! any suggestions?

Hmmm. What kind of problems?

Sounds like you might be using the reducer intended for their urethanes. It's potent stuff! I avoid it for health reasons. Unless you're painting 1:1 cars, you won't lose any of the benefits of automotive paint if you thin it with hardware store lacquer thinner. And it's a lot safer to handle.

Ddms

Sixx
01-21-2008, 10:37 PM
You're right Didy! I needed to thin my paints more even though they (MCW) says they're ready to spray! I've had to thin them even more and it seems to work out just fine!

As far as the thinner goes, I am using a generic Dupont laquer thinner. I do have reducer for some other paints and they are too strong. is there a more mild thinner available at a hardware store that you can recommend?

take it easy
6

Adam Baker
01-21-2008, 11:04 PM
Sixx, have you taken a look at the Duplicolor Paint Shop laqcuer thinner?

Didymus
01-22-2008, 10:45 AM
As far as the thinner goes, I am using a generic Dupont laquer thinner. I do have reducer for some other paints and they are too strong. is there a more mild thinner available at a hardware store that you can recommend?

You're right; those urethane reducers are very powerful and highly toxic. I tried one, but the generic lacquer thinners work very well with Chromabase. The one I'm using now is called KleerStrip.

I realize that generic thinners are not as consistent and that they don't have some of the refined characteristics that 1:1 painters like, but when I use them with Chromabase, I get that same great satiny, nearly OP free finish, and they flash and cure at a perfectly acceptable rate, e.g., not instantly, but a helluva lot faster than Tamiya TS series.

Diddy

Add your comment to this topic!