Thinning Tamiya paint with water vs isopropyl

Welcome back to the hobby Gonzo and welcome to the forums. I use Tamiya acrylics for airbrushing as well and I only use isopropyl alcohol to thin them. Likewise, I began doing that upon reading it as a suggestion from other modelers but I'm not sure what the difference is. I've never tried to thin acrylics with demineralized water, but I've tried with regular tap water and found that to be insufficient...didn't seem to blend well together. So, at least for me, it was "just one of those tips" that I haven't really turned away from. Sorry I can't help much more than that.

Thought I read somewhere that it's a bad idea to thin Tamiya paints with water.

I thin Tamiya with high-quality lacquer thinner...either Tamiya's own, or Gunze Mr. Leveling Thinner. I've found it sprays far smoother, with less tip dry. You can also reduce the heck out of the paint for subtle effects, filter coats, post-shading, etc. I've tried iso and denatured alcohol, but I just don't like them as much.

I typically clean up with Windex.

Thanks for the reply and the welcome, oddmanrush.

I would think that thinning with isopropyl makes the paint dry even faster since it should evaporate faster than water, so that would be a good reason for me not to use it. I'm glad I learned that adding retarder will slow the drying as it is. Haven't had any more orange peel mishaps since. 8^)

I try and stick with the Tamiya thinner for their paints...Ive used the alcohol as well seems to be OK..Ive also used it with MM acryls and found that it thins it well but builds up in the AB tip...remember alcohol evaporates really fast...this can lead to a grainy finish....also depends on your local weather....I live in Fla....high humidity most of the year....A/C in the house....not as dry as say further north where the heat may be on in the house...hate to say its but it trial and error...

Good luck

Carlos

Funny how there are all these different subtleties and preferences in modeling. I guess I've always stuck with the Iso since its so readily available at the corner drug store or super market. True though, I notice I do get a lot of build up around the tip. There always seems to be something to consider changing or adopting when it comes to modeling...

Tamiya thinner is basically Iso with some retarder, but yes the Alcohol will speed up surface drying (as opposed to curing, there is a difference). I keep reading about people using the lacquer thinner with better results, and I'll try that the next time I need thinner. Which will be about two years, as I had the LHS order in some big bottles of Tamiya thinner for me, and I guess I better use them up first!

I try to stick to Tamiya thinner for the actual airbrush work, I use the isopropynol for cleaning up with though. Never tried water for either.

VanceCrozier

I try to stick to Tamiya thinner for the actual airbrush work, I use the isopropynol for cleaning up with though. Never tried water for either.

I wonder how Cat-nip would work...???

MEOUW

C

Tried it - dries well but clogs up the airbrush. It also gets hard to wrestle the airbrush away from the cat!

I'd probably just use Tamiya thinner as well - IF I could find a place that still has some old stock. I'm not sure why Tamiya can't just slap new labels on their stuff and start selling it again.
Still not sure that I've seen a good reason to use iso over demineralized water..

It really depends how much thinner you're adding to the paint.

If you add water to Tamiya acrylics in the region of one part water to two parts paint, the effects on adhesion are fairly negligible. If you add more than one part water to one part paint, you will start to see separation and beading.

If you use Iso (or Tamiya's own acrylic thinner) you can take it up to about three parts thinner to one part paint and then much past that and it will start to bead and behave like it's thinned with water.

Denatured alcohol will allow you to go much thinner while retaining adhesion - I've taken it to 90% thinner and still had good coverage.

Tamiya Lacquer thinner and Gunze's Mr Color thinner give spray properties similar to denatured alcohol, but with even better "bite" and coverage, but you might not likethe fumes.

*NOTE: Do not thin gloss Tamiya acrylics with water, straight Iso or denatured alcohol, as it will produce a less than glossy finish. Use Tamiya's own acrylic thinner or their lacquer thinner.

Generally speaking, Tamiya acrylics airbrush better when very thin. ie. two parts thinner (or more) to one part paint. I think that many of the problems that people have when airbrushing Tamiya acrylics occur due to insufficient thinning.

Phil_H

It really depends how much thinner you're adding to the paint.
...

Thanks for giving some insight on this subject, Phil.

I will try using an isopropyl/retarder mix until Tamiya is selling their thinner here in the US again. Sounds like that this is what it is composed of anyways.

Ok - the iso/retarder is simply iso and distilled water . . . I thin my Tamiya smoke fairly thin to use as a wash on all WWII large scale airplanes - it works really well with about a 50/50 mix of paint to thinner which is itself about a  50/50 mix of iso and distilled water - remember I'm going for a wash here - and I dont't want it to dry too soon - plus I WANT some pooling of dark in the creases and seams -

plus I run my airbrush in the direction of the airflow to get that natural streaking  . . . YMMV but that works for me - I never air brush any Tamiya for the actual color - since WWII ETO is RLM colors [used Gunze from about 1988 until 2005 when it became unavailable and that was 80/20 iso/water] where I know airbrush Vallejo almost exclusively  . . . .

I'm having a few problems with my tamiya acryls. I'm pretty sure I got the mixture right but it's still coming out thin and watery. I'm airbrushing at 20 psi which works good for MM acryls.

I always use Tamiya X-20A acrylic thinner.  Don't know what's in it, but never had a problem.  I clean up with soap and water, except for the airbrush, which I clean by spraying X-20A through it at high pressure.  Never had a problem with this method.