Tamiya Paints In An Airbrush?

[Beowulf]

I finally found the paint I needed for my Romulan Warbird. Now my question is this.
Since Tamiya paints are alcohol base, is it good just to thin it with rubbing alcohol for airbrushing or should I use something else?

Thanks in advance.

[Kylwell]

I use Tamiya's thinner for thinning their paints for use in an airbrush. I've tried isopropyl alcohol, and the other form of alcohol, along with distilled water. Never got decent results. Sometimes the paint would curdle, or seperate, or gum up in the airbrush.

But....other folk here have had good results with using rubbing alcohol. I'm just lazy and perfer the ease of using Tamiya's thinner.

[macfrank]

I finally found the paint I needed for my Romulan Warbird. Now my question is this.
Since Tamiya paints are alcohol base, is it good just to thin it with rubbing alcohol for airbrushing or should I use something else?

Thanks in advance.

Isopropyl alcohol works fine (make sure it does not contain oil), denatured alcohol works better. Windshield wiper fluid works well, too... and it's cheap.

[Kylwell]

Windshield wiper fluid? Never tried that...and now I must, as my laziness is overran by my cheapness.

[Jagdson]

I used to have good results thinning Tamiya paints with saliva, but that was for hair-brushing. Their brand of airbrush thinner does work very well, even through my cheap Aztek. It's not that much more expensive than a bottle of Windex.

[Marcal]

Tamiya thinner is a mixture of isopropil alcohol (2-buthanol, isopropanol, is everything the same) and water. I believe that the ratio is more or less 8 to 2 (alcohol:water). Isopropil alcohol is not so much diferent from ethanol (ethyl alcohol) from the chemical point of view. The main difference is their boiling points (76 and 82 °C respectively)and steam pressure (I don´t know if it the correct term for it but represents how fast the liquid evaporates).

With this background I tried out to use ethanol instead of the Tamiya thinner. I found a useful to use 6 times of ethanol for 4 times of paint. What i think is important is to get the correct preassure in the airbrush. I you put too much preassure, the solvent evaporates before it hits the surface of the model and then you get a sand-paper surface in your model. If it happens you can try to remove it sanding it with a non-greasy finger or a normal paper (no sand paper).

But as usual the best thing is try out in a scrap before to mess up your model.

Post the results !!!!

[macfrank]

Tamiya thinner is a mixture of isopropil alcohol (2-buthanol, isopropanol, is everything the same) and water. I believe that the ratio is more or less 8 to 2 (alcohol:water). Isopropil alcohol is not so much diferent from ethanol (ethyl alcohol) from the chemical point of view. The main difference is their boiling points (76 and 82 °C respectively)and steam pressure (I don´t know if it the correct term for it but represents how fast the liquid evaporates). !

The main difference in using Isopropyl vs denatured (ethanol+whatever they add to make it undrinkable) is the water content. Most drug store rubbing alcohol starts out at 70% Isopropyl (at best) and 30% water, and drops as the alcohol evaporates from the bottle. Denatured alcohol starts out at 95% Ethanol + 5% whatever and no water, and this ratio doesn't change. The main effect when using it to thin acrylics is to cause the paint to dry faster and to reduce its surface tension.

Windshield wiper fluid is (depending on the brand) water + some type of alcohol (methanol or isopropyl) + a surfactant to lower the water's surface tension (so you don't get water marks on your windshield). It's cheap and works about as well as the Isopropyl, although it has little effect on the drying time (which can be a problem with ethanol if the ambient humidity is low).

You can also get the same results by mixing a tiny amount of Kodak Photo-Flo 200 with water. A standard Photo-flo bottle will last decades in as a thinner for acrylics.

Frank

[Beowulf]

Lots of good advice here. I'll experiment with some alcohol as a thinner and see what happens.

On the windshield wash.....it's blue. Wouldn't that create a problem? I'm applying Clear Green paint.

[Marcal]

I don´t think that this thin blue color gives any problem. just try it out and see what happens. It it does what you can also do is to prepare a mixture of alcohol, water with a couple of drops of soap. This will also reduce the surface tension of the mixture... You see, chemistry is sometimes useful.

[TER-OR]

Isopropyl alcohol is sold as 70% for antiseptic uses. The alcohol/water azeotrope is more effective at killing microorganisms than the pure alcohol. The azeotrope also means both liquids evaporate at the same rate, the ratio won't change.

You can also purchase 99% Isopropyl alcohol at the grocery or pharmacy. This is what I use to thin Gunze and Tamiya paints. I've never had troubles doing this.

Ethanol is 2 carbons, Isopropyl has three, but also has a branched structure - hence ISOpropyl not n-propyl. I find the surface tension of isopropyl alcohol to be lower than ethyl, which I think helps paint coverage.

[Marcal]

...The azeotrope also means both liquids evaporate at the same rate, the ratio won't change.

...this isn´t right at all. The term azeotrope means that it is not possible to isolate both components by simple distillation. The process goes in this way: if you heat the mixture up, the alcohol starts to evaporate until the mixture reaches a precise ratio. At this point of time both components evaporates at once. So it is not possible to separate them using simple distillation. You have to use other methods.
So if you have a bottle of an azeotropic mixture open, the ratio will not remain constant.

ETHANOL is also used in medicine also the ratio it is mencioned. METHANOL (1 carbon), however, is not useful for medicine. If you drink it you can get blind or even die if the amount is large. It is because it has a conpetitive interaction with the enzime alcohol deshydrogenasa, which is the responsible for the assimilation (resistance is futile) of the ethanol, also the one we drink. So please, if someone is using methanol as thinner, be careful with it.

I also get and use the alcohol in a pure form, without water, and that far works well.

[macfrank]

On the windshield wash.....it's blue. Wouldn't that create a problem? I'm applying Clear Green paint.

Doesn't affect it. I've even used it with white paint and it sprayed (and stayed) white.

[Jonas Calhoun]

Personally, I've tried most of those mixtures. They didn't work nearly as well in the airbrush as using the paint brand's thinners. Hand brushing, yes. Although look up--a lot of people have good luck with them. I'm with Kylwell though, my laziness is overcoming. It's just much easier that I don't have to remember ratios.

There are some retardars in the Taimya and Gunze thinners that keep the paint from drying out quite as fast. I've used Liquitex's slo-dri for the same effect when handbrushing.

Dan

[eeun]

I've been using methyl hydrate for a couple years now, with Tamiya acrylics as well as with Liquitex artists acrylics.

No problems with second coats or subsequent gloss / matte coats and weathering. I also use it in my satin coat mix (something close to 20% Microscale flat, 20% Methyl Hydrate, 60% Future Floor Polish).

I didn't have good results with isopropyl, but judging by the number of those using it, it must be me.

[Less Than Super Ostrich]

Nerds.







Just kidding. I'm just bitter because I didn't do so well in high school chemistry. I just buy the Tamiya thinner and go on my merry way.

[Marcal]

I've been using methyl hydrate for a couple years now, with Tamiya acrylics as well as with Liquitex artists acrylics.

Methyl Hydrate is a synonim for METHANOL. As said it is useful for cleanig, burning and so on. But if you are airbrushing it, please be careful, do not breathe the steam. It is very toxic.
It is only another alcohol, with solvation properties similar to the other mencioned, but with different boiling points and steam pressure... I gives different airbrush-thinner properties.

If it worked, even cola would be a good stuff

[macfrank]

If it worked, even cola would be a good stuff :D

Cheap vodka would be good... but as you say, you have to be careful because the vapors are very dangerous!

[Marcal]

If it worked, even cola would be a good stuff

Cheap vodka would be good... but as you say, you have to be careful because the vapors are very dangerous!

good point

[Slave1]

You could probably get high pretty fast off of that stuff (Dont try it though)

[TER-OR]

http://eweb.chemeng.ed.ac.uk/chem_eng/a ... _bank.html

Automatic information for azeotropes.


http://en.wikipedia.org/wiki/Azeotrope


I'm pretty sure both portions of the azeotrope exist at the same proportions in the vapor phase whether evaporating or under heat or ambient conditions. Under a vacuum distillation, they can be separated but under normal heating and boiling IIRC, they remain constant in the liquid and vapor phases. During co-evaporation the azeotrope should remain.

Not that it's particularly relavent to the conversation - though, if a portion of the azeotrope remained behind longer than another it could affect the drying of the paint. Water alone evaporates more slowly than the azeotrope with alcohol, and alcohol more quickly. The blend in the thinner does affect the paint curing.

[Marcal]

Is has gone too far

You made me check my physical chemistry notes from the university and I hate it. When I finished those subjects I though taht I would rather let someone cut my right hand off than to check these notes again. Well, in my notes appears what I have explained... But because of you seem to be very sure too I checked my f****ng physical chemistry book. In the book appears your version So there are two possibilities:

1) I missunderstood what the teacher said.
2) The teacher was confuse the day he explained it to us.

Well whatever it is, I'm so glad of three things:

1) that I have never tried to teach physical chemistry
2) that no one asked about azeotropes in the final examination
3) after 7 years since I finished this subject, I have learned the true


have fun,

[TER-OR]

I sincerely apologize for causing the torture of consulting your physical chemistry tomes. I, for one, couldn't handle the calculus for that part of chemistry. It made my brain hurt.

Or could it have been all that carbonated 6% alcohol/water azeotrope?



It does explain why adding alcohol to the paint will speed its drying, though.

I've also found that adding alcohol to Testors Acryl is bad juju. Stick with water.

[macfrank]

I've also found that adding alcohol to Testors Acryl is bad juju. Stick with water.

I add denatured alcohol to Acryl often, if I need it to dry faster. No problems at all.

It also tates off dried Acryl with little effort (something that isopropyl can't do).

[TER-OR]

That's good to know. So far I haven't needed to thin the Acryl much, but removing it is another matter. Other than soaking in window cleaner (with ammonia) to remove it all I haven't found much success.

It does thin well with the PolyScale thinner - aka diosol. Probably because they're pretty much the same products.

[Beowulf]

Well, I had some rubbing alcohol in house. It was the good stuff, 91%, and used it on Clear Green for Warbird Nacelles. It worked like a champ.

[TER-OR]

Make sure you clearcoat the clear paints - they can stay sticky.