How many of you use home brew thinners for acrylic paint?

Brew your own thinner? Nope. You're better off buying them. Every brand paint, be it lacquers, enamels or acrylcs have different properties and chemicals. No two thinners are alike; thus the reason to stick with the brand thinner to your paint. I use Testors brand Universal acrylic thinner for all my acrylic paint.

Acrylics are a peculiar lot when working with "improvised" thinners. What works well with one brand, may not work well, or worse, with another. There is no one size fits all answer for acrylics due to the various paint formulas out there sold as acrylics. Obviously the manufacturers own thinner will yield best results with their product. But then if you are like many folks here you have more than one brand in your paint supply and may end up with multiple thinners as well. Some acrylic thinners may work with more than one brand of paint, but they certainly will not work with all brands. 

Welcome to the hobby and good luck to you.

Yup:

been there done that: Windsor & Newton Art brand retatders/extenders with IPA:

Results: Inconsistent with several brands & disaster with Vallejo due to IPA.

My 2c/Tuppence h'apenny:

Stick with the brands' own thinners retarders/extenders, you will get much better consistency & repeatability...

Tamiya will work with IPA, Halfords' (UK) own-brand windscreen wash, but best with X20a.

VJ ModelAIR will only work consistently with own brand Thinner, Future (!) or Ultimate  brands, my preference is MEDEA brand airbrish cleaner.

VJ Polyeurethane Primer thins a little with Future.

Hataka will spray, but is very fragile on anything that isn't primed especially resins, use their thinner.

Xtracrylics thins with Medea brand or their own.

Here is how I think abou it. The folks who formulate the paint have education, training, and experience that I don't have. I doubt that I can outsmart them.

Seems like this is NOT a widely used practice though the cost savings sure make it an attractive option.  That said being 4 kits into the hobby, I have only used about a third of the Tamiya x20a thinner that I bought for around $9 a couple months ago. 

I will continue to stick with the Tamiya x20-a thinner that I have been using.

Thanks to all of you who replied.

Own brand thinner for me as well. Only exception is Tamiya.I use the halfords own brand screenwash.

If you're working with Tamiya, I can send this tidbit. One of our IPMS chapter members is a chemist by trade. So he did an analysis of Tamiya thinner. 98% Isopropyl Alcohol and 2% fragrance. So if you are just speaking strictly Tamiya, and suddenly run out and have no hobby shop nearby that has Tamiya thinner on hand, Isopropyl Alcohol is a viable option.

I use denatured alcohol for a lot of things (like shellac). How does that compare with using isopropyl? Can you ask the chemist?

I am of the understanding that Tamiya Acrylic use an acrylic based laquer thinner.

So, I use an automotive acrylic laquer thinner with excellent results. Its easily available and its far cheaper than a branded Tamiya product by volume by a considerable margin.

The only down side is that I needed to build a spray both to evacuate the fumes.

ugamodels

I use denatured alcohol for a lot of things (like shellac). How does that compare with using isopropyl? Can you ask the chemist?

 

Denatured alcohol is not a type of alcohol.  It means a poison additive is put into it to prevent it being drunk.  Based on tax situation for ethyl alcohol.  So it is usually ethyl.  Isopropyl works great as a thinner for most acrylic paints, and has other uses in model building. I always keep a bottle on my work bench.