Acrylic paints and lacquer thinner

There's a real handy guide to paint and thinner compatibility available as a download from Model Airplane International magazine. Go to modelairplaneinternational.com, click on "more" on the Downloads menu selection, and select the paint chart. The PDF link is a little confusing, you click on the brown title block above the chart.

I got this info from a previous post on a Fine Scale forum...thanks FSM!

   No big deal really...just me being anal. But as a correction to my last post, I meant conversion varnish, not catalyzed lacquers.

Rich

No, I have not noticed the ML Campbell Lacquer thinner to be "Hotter" than Mr. Color thinner or Tamiya's.

I'm definately NO expert, just a modeler. 

@Ross (Triarius)

Thanks for sharing this information with us.  Your wealth of knowledge on this topic is invaluable.

@Steve (STJohnson)

I checked out the MSDS on the M.L. Campbell "Standard Lacquer Thinner".  The main ingredient is Toluene (66% by weight), which I think is also the main chemical in Testors tube glue.  Have you noticed it being a little hot when compared to Mr. Color Thinner?

 ----

I looked at a number of MSDS sheets for "acrylic lacquer thinner" from various suppliers, and I now understand what Ross means when he says "cocktail" of strong solvents.  Acetone, Toluene, Xylene, and Methyl Ethyl Ketone are the most common solvents, but there are others as well.   Being a neophyte on the topic, I'm left scratching my head at all the options.

It seems that the thinners that are supposedly less hot have more Toluene and less Acetone in their chemical makeup.  But I could be totally wrong in that assumption and was hoping that one of you experts can enlighten me a little.

Another thing and I don't know if Ross addressed it or not as I didn't ready every post, is that sometimes lacquer thinners can make acrylics gum up in the airbrush.

I sometimes will use a little lacquer thinner to clean if the airbrush is stubborn coming clean with Windex, Simple Green or 91% Iso alcohol. I used to have that problem with MM Acryl as it would stick to the color cup like glue and the only thing that broke it down was lacquer thinner or letting Super Clean degreaser sit in the cup for an hour. 

For thinning Tamiya paints I came across using Ethyl Alcohol 70% as it was recommended to me by another modeler on here and it has worked great ever since. I may experiment with other things like Iso Alcohol but not lacquer thinner. If I were going to use lacquer thinner I would just go back to enamels but I don't plan on that.

Thank you Ross,

   I realize how complicated coatings in general can be. My whole life has been spent in the custom cabinet/woodwoking industry. In that time alone I've had to try and grasp the basics of finishes ending up with catalyzed lacquers for the time being, (that is until Arizona will be required to switch to water based finishes). So I can appreciate the knowledge base you have on your side, and I thank you for taking the time to lend me your advice and opinions, as they will certainly help me make the proper decision(s). 

Rich

I mean don't do it at all. It is unnecessary, and merely adds another complication.

Windex with ammonia is close to being the universal cleaner for hobby acrylic paints, including Future. Some paints (Polly Scale is one) are more susceptible to the combination of Windex and Simple Green. I suspect that aqueous solvent system paints are more easily cleaned with the combination.

Some use lacquer thinners to clean acrylics from their airbrushes. I see this as a "nuke and pave" approach. It is effective, especially if you forgot to clean it the last time you used it!

So you know: I worked in the coatings industry as a technician and later as a formulator/chemist. I worked with coatings chemists most of my professional career as a materials scientist. So I have a pretty extensive general background in the field.

Most experienced modelers are experimentors. They find something that works for them and pass it on. This is empirical knowledge, often without the benefit of technical understanding of all the possible issues. Use at your own risk. I have much of that technical understanding (and access to what I don't know.) My recommendations are based on that. I have already explained (many times) why I consider the use of lacquer thinners with acrylics unnecessary and risky.

Paints are enormously complex. Why add another variable, especially when there is no particular benefit, it is more expensive, and hazardous as well? I suspect that most of those who use (or abuse) acrylics this way do so because it makes acrylics behave more like the enamels to which they are more accustomed. Acrylics are different. Learn to use them properly and you'll never look back. For that matter, you won't be able to go back. In the next five to ten years, enamels will be relegated to specialty applications and will be uncommon in general use.

   That being said, I have also received a great deal of sound advice from these forums, thus was my reason for asking about the combination in the first place. So Triarius, when you say do not use any lacquer thinner to thin my acrylics for spraying, do you mean don't do it period! Or don't use just any old combination of the two...other than those already proven to be compatible, as Rick Lawlers piece in FSM. Or perhaps as Steve discussed when he replied to this topic?

   Like Steve said, I'm not wanting to make waves here. But I've read about this twice now in FSM, as well as other sources on the net...all with rave reviews. So I don't want to dismiss a winning technique before finding out the truth. So thanks for everyones imput so far.

   Oh ya, one more thing. Is any decent lacquer thinner ok just for cleaning my airbrush and/or regular brushes? Or does everyone just use Windex & Simple Green? I guess I'm a bit unclear as to the Windex thing. I'm not sure if people mean that the Windex combo is just for cleaning Future, and not really for the acrylic paints themselves?

Thanks in advance everyone,

Rich

There are acrylic coatings that use solvent systems other than alcohol or water. As you were told, these are generally specialized coatings for specific applications. Unless you really know what you are doing (i.e., you work in the specific industry and are therefore very familiar with the coatings and their application technology) I would recommend NOT trying to use them or their proprietary materials on scale models.

Also, there is no such thing as an "acrylic lacquer" per se. Acrylic polymers are just that: they form films by polymerization (curing) not by drying. In use, the term "acrylic lacquer" is similar to the term "enamel lacquer." Both are shorthand for a polymer combined with a true lacquer resin (natural or synthetic). Thus, an acrylic lacquer is an acrylic polymer combined with a solid resin that is soluble in the same solvent (or a compatible cosolvent) as the polymer. This is generally done to speed drying to the "tack free" stage and/or to modify the appearance or durability of the cured film.

Oh forgot again.. The evaporation rate seems to be a similar or maybe a little slower than the Tamiya lacquer which is probably why I like it for my AB

Steve

Hi deekay1

Oh sorry I should have mentioned it.

I use Tamiya lacquer thinner currently 250ml seems to be the better buy. I have tried Mr Color thinner but did not notice any difference.

I really do not like the hardware store thinners much ,except for cleaning ,but you can always experiment.

I am currently testing Lacquer Thinner sold by  M.L. Campbell it is called "Standard Lacquer Thinner" C 160 36. The description on the can says..."A high quality thinner. A special blend of solvent specifically designed to be an excellent reducer for nitrocellulose, precatalyzed, buyrate and Acrylic Lacquers".. It was this last one that caught my eye. A gallon cost $17 here (Iowa). It seems to work every bit as well as the Tamiya but I would like to give it more time to be sure. I use this lacquer allot in the wood refinishing shop where I work and all of their products are superb. I but it locally at a paint shop. I don't think it's available in anything smaller than a gallon.

Thanks

Steve

Oh I forgot to mention one very important thing.  Air pressure at the brush. I prefer a small regulator attached to the end of my AB and can make adjustments on the fly. If you can get one (to fit) I highly recommend it . Especially for real fine detailed work as mentioned in my previous post.

Its just as important as thinning and keeping the brush clean :)

Thanks

Steve

Hello

I don't mean to start a debate, but I have been spraying Tamiya acrylics with lacquer thinner for about a year now and personally, I thought it gave better flow/atomization thru the airbrush than their X20 thinner. Please understand that I notice this difference mostly when spraying with a very small Needle/Nozzle combo. I use .15 or .18mm for freehanding the outlines of camo or mottling on fuselage sides, figure painting, or touchup & repairs just for example.

I seem to get allot less skipping and drying on the needle tip.  I remember being very frustrated with Tamiya acrylics because they kept skipping  even though I was keeping the tip very clean and paint strained and properly thinned. I read about using lacquer thinner somewhere and thought, what the heck give it a try on some plastic scrap. I don't really think its a secret or anything. It just works great and its all I use now for spraying. I have had no trouble at all on any plastic. I still always spray my Acrylics over a primer base.

 I have a little experience with Mr Color and have used the Mr Color Thinner and Tamiya's lacquer thinner and Mr Leveling thinner which has a drying retarder in it. They all work just fine. You might have to adjust your ratios alittle bit

The Gunze acrylics have two versions. The version that is called Mr. Color ...I think states on the back of the bottle that it is a solvent based acrylic and  there's the "Aqueous" line which is not. Some Acrylics like Model Color/Air ..Lifecolor and the Aqueous line have a completely different chemistry and should not be thinned with anything but H2O or their own solvents..for spraying I mean.

I also sometimes use "Future" and I spray it right out of the bottle after I strain it thru the wifes old stockings. BTW.. I recommend straining everything except solvent that goes thru your AB.

I have not tried mixing colors with future and cannnot comment.

I recommend changing  to a larger Nozzle/Needle AB if you can ,when spraying Future.

You'll never know till you experiment..Be sure to remember to wear your respirator  and crack a window :)

Steve

Yes, thanks Phil.  I can't speak for others, but my interest in an "ordinary" lacquer thinner has everything to do with the high cost of Mr. Color Thinner / Mr. Color Leveling Thinner.

 Triarius brings up a good point about the chemical composition of ordinary hardware store lacquer thinner (versus Mr. Color Thinner).  I'd be interested to know what the chemical composition of Mr. Color Thinner is .....

deekay1us wrote:

Would Gunze's solvent-based "Mr. Color" acrylic be included in this warning?  I'm curious about it because I've read online that some modelers are successfully using lacquer thinner with Mr. Color.  However, there doesn't seem to be any agreement over which lacquer thinner to use.

The "Mr Color" range IS formulated around a "lacquer" base, and is intended to be thinned with "Mr Color" thinner which is, I believe, somewhat different to "generic" lacquer thinners.

I think a lot of the talk about using lacquer thinner with Tamiya paints is really just over-hyped "this is my secret method" stuff.

People will go as far as saying that Tamiya acrylics aren't true acrylics because they can be mixed with this that or something else. In reality, it's not the reducing medium which determines whether a paint is acrylic or not, it's the basic polymers in the binder and how they cure which makes that determination (and Tamiya paints DO contain acrylic resins in the binder).

While some people do use "lacquer thinners" with Tamiya and Gunze acrylics, I suspect that they work, as Ross has stated, because they (eg, Tamiya "LAcquer thinner" and Gunze "Mr Color Thinner") have a higher proportion of alcohol in their formulations, which IS compatible with Tamiya and Gunze acrylics. It's interesting also to note that these two brands are said to be styrene friendly and one can soak styrene parts in either without them dissolving into a pool of slime.

I use Tamiya X-20A acrylic thinner and I also use Methylated spirits, which here in Australia is 90%+ Ethyl alcohol. This is perhaps a little "hotter" than Isopropyl alcohol, which is the primary constituent of Tamiya X-20A, but not overly so. Ethyl alcohol does "flash dry" faster than Isopropyl, but you can add acrylic retarder to it to reduce this.

Water, in the quantities required to thin for airbrushing, isn't recommended for Tamiya or Gunze acrylics, as it reduces adhesion and encourages beading. Water is recommended, however, for other brands such as Vallejo.

I would recommend buying the 250ml jugs of Tamiya thinner over the paint jar sized bottles - the bulk packs are much more economical. ($3.00 for 10ml vs $10.00 for 250ml - no contest)

Triarius wrote:

Tamiya's X-20A thinner is essentially 90 percent isopropyl alcohol with the proper amount of acrylic retarder. Anyone who cannot produce a beautiful finish with that and their paints should go back to building Lego kits (they're actually pretty neat, but you get the idea.)

Absolutely - if you can't get a good finish, then something is terribly wrong.

Original Tamiya thinner may cost a bit more than the substitutes, but today's kits are expensive - why pay upwards of $40.00 for a kit and then give it a cheap and nasty paint job?

Why would one want to use lacquer thinner with an acrylic anyhow?

Isn't the whole reason for using acrylic paints to get away from the toxic compounds of lacquers and enamels? 

Would Gunze's solvent-based "Mr. Color" acrylic be included in this warning?  I'm curious about it because I've read online that some modelers are successfully using lacquer thinner with Mr. Color.  However, there doesn't seem to be any agreement over which lacquer thinner to use.

Be careful about believing what you read.

DO NOT thin acrylics of any kind with "lacquer thinner." Lacquer thinner does not have a specific compostion. It can be anything from essentially pure alcohol (compatible with Tamiya  and Gunze acrylics, but not with Polly Scale, Model Master, and others) to an esoteric cocktail of various strong organic solvents like toluene, acetone, methyl ethyl ketone, others, and usually a little alcohol. Many of these solvents will dissolve styrene.

Tamiya's X-20A thinner is essentially 90 percent isopropyl alcohol with the proper amount of acrylic retarder. Anyone who cannot produce a beautiful finish with that and their paints should go back to building Lego kits (they're actually pretty neat, but you get the idea.) Or you can get 90 percent isopropyl and add your own retarder. This works with any alcohol solvent acrylic system like Tamiya or Gunze. it does not work for systems that use water as the principle solvent, like Polly Scale.

Windex with ammonia is the best cleaner for acrylics, and is nearly universal. A mixture of Windex, Simple Green, and water will clean/strip almost all hobby acrylics (haven't found one it didn't work on, yet.)

Future has been used as an additive to some hobby paints, particularly Tamiya and Gunze, with which it is completely compatible. However, adding an aqueous system paint, such as Polly Scale, to Future may have unpredictable results. If you must (Why would you?) try such combinations on a small scale in a disposable container.