Things I Learned Today

[Thommo]

A lot of my Tamiya acrylics have dried up in the jars, so I went to the local hobby shop to get some more. They were way down on stock & waiting for new paints to arrive, so he talked me into trying Vallejo acrylics. They were also out of Tamiya acrylic thinner, and said I could just use clear Windex. So tonight I learned:

• Vallejo is a bloody good paint, though even it won't work well in the tan tip of the Aztec airbrush (works fine through the black tip though)
  
• Windex works fine as a thinner
  
• You can mix Vallejo & Tamiya acrylics with no problems
  
• Windex also works well as a thinner with Tamiya acrylic
  
• Breathe into the jar of paint before sealing it - the CO2 helps stop it drying out (according to the bloke in the hobby shop - can't confirm that yet)
  

Edited April 30, 2014 by Thommo

[RichardL]

Mixing Vallejo and Tamiya is asking for trouble - totally different chemistry. The problem might not show up right away but a few months or years down the road while your model is in the display case.

Vallejo paints are true acrylic while Tamiya paints behave more like lacquer and can be thinned with lacquer thinner.

[galileo1]

Did Vallejo change their formulation by any chance? I keep reading about people using Windex to thin them. I tried this myself and all I got was a congealed mess.

Rob

[Triarius]

Things you shouldn't have learned today:

Thinning any acrylic with Windex (or equivalent)—ammonia is hard on acrylic polymers.

Considering Tamiya acrylics as lacquers. They aren't. Nor should you use any "lacquer thinner" with an acrylic paint. Lacquer thinner is a blend of solvents, one of which is likely to work with any of a number of polymers—and several of which are probably incompatible. Lacquer thinners usually contain a high proportion of alcohol, the primary solvent for Tamiya and Gunze acrylics. Just use 90% isopropyl with a retarder, or Tamiya's thinner.

CO₂ is inert, and storing paint in an inert atmosphere is not a bad idea. However, human exhalations contain relatively little CO₂ . They also contain a lot of moisture, aerosolized saliva, abundant micro-organisms of various sorts, and a lot of oxygen. All of the latter are bad to very bad for acrylic paint. Just clean the sealing surfaces and tighten the cap.

:bandhead2:/>

[Thommo]

OK lets view it as an experiment then, and see what happens. I'll have to remember to re-visit this thread in a few years time!

And I've just read some of the Vajello paints have 'do not spray' on the bottle (maybe as they contain cadmium?) - sheesh!

[chuck540z3]

Considering Tamiya acrylics as lacquers. They aren't. Nor should you use any "lacquer thinner" with an acrylic paint.

I have to disagree with the above statement, not because I actually use Tamiya lacquer thinner with their acrylic line, but a friend of mine does all the time and he swears by it. He also creates some of the very best paint finishes I've ever seen.

I found the following on Tamiya USA's website which explains why you might want to:

"Tamiya acrylic bottle paints are excellent for airbrushing plastic model kits whether you're building a model tank, airplane or car. When you begin using Tamiya bottled acrylic paints, we recommend thinning the paint for the best possible airbrush experience. Airbrushing Tamiya acrylic paint directly and un-thinned from the bottle is usually too thick for most applications. It's suggested to use the two thinner options available from Tamiya's finishing supply product line-up.

The first choice is the X-20A Thinner and the second is the Tamiya Lacquer Thinner. Tamiya X-20A is the easiest to work with as clean-up is simple and less messy for modelers who are new to airbrushing. The paint will dry slower using X-20A which will give modelers more time to work with the paint.

For advanced modelers Tamiya Lacquer Thinner will yield two main benefits, but at the expense of a messier clean-up. Tamiya paint thinned with Tamiya Lacquer Thinner will result in the paint drying much faster and the paint will have a harder shell. For modelers who sand their work, a harder finish is preferable. A softer shell is easier to over-sand and it's easier to go too deep into the paint.

A good starting point for achieving the proper paint to thinner ratio is to get your mixture close to the consistency of milk. If the paint is thinned too heavily the paint will appear opaque and it will be easier to run and drip."

[Triarius]

I just looked at the MSDS for Tamiya lacquer thinner. While it contains almost no useful information, the flash point is listed as 53.06°F (Tag open cup), identical with isopropyl alcohol.

From the description of the behavior of the two Tamiya thinners, their X-20A is probably isopropyl alcohol, possibly slightly diluted, with a small amount of retarder. Their "lacquer thinner" is probably a more concentrated isopropyl alcohol, possibly with additives. It is perfectly legitimate for them to use the imprecise and common term "lacquer thinner" to describe the latter product. If it is, indeed, isopropyl alcohol, then it will thin most non-synthetic lacquers.

So why use lacquer thinner at all? Isopropyl is cheaper and can be had in any (US) drug store. Lacquer thinner often contains (it can contain anything) other, much more noxious solvents that are also aggressive to plastic. Using such a solvent, to me, indicates an unwillingness to learn to use a material properly. When you mistreat a material, sooner or later it bites back.

Contra stultitia, deos ipsos se frustra contendere. Quare ergo me?

[Thommo]

And just to complicate things, I've found plenty of websites where people recommend using Windex to thin Vallejo paints.

The other interesting thing is, of the 3 bottles of Vallejo I was sold (2 are Model Color, 1 is Game Color), only one says 'contains Cadmium do not spray (the Model Color Olive Green). Yet the same label also says 'Non Toxic'.

Anyhow, to date I've learned that after 24hrs, a mix of 50/50 Vallejo and Tamiya paint thinned with Windex is still perfectly attached to my model - only time will tell if it remain that way.

Edit to say, in the past I have mixed Tamiya, Gunze and Model Master acrylics, all thinned with Tamiya thinner and it all seemed to work OK.

Edited April 28, 2014 by Thommo

[RichardL]

I have mixed Tamiya, Gunze and Model Master acrylics, all thinned with Tamiya thinner and it all seemed to work OK.

Tamiya and Gunze are very similar to each other, so you should be OK mixing them. MM Acryl, on the other hand, does not do its best when thinned with Tamiya thinner.

[RichardL]

Read this thread from FineScale Modeler: Thinning Tamiya with Lacquer Thinner

[chuck540z3]

I just looked at the MSDS for Tamiya lacquer thinner. While it contains almost no useful information, the flash point is listed as 53.06°F (Tag open cup), identical with isopropyl alcohol.

From the description of the behavior of the two Tamiya thinners, their X-20A is probably isopropyl alcohol, possibly slightly diluted, with a small amount of retarder. Their "lacquer thinner" is probably a more concentrated isopropyl alcohol, possibly with additives. It is perfectly legitimate for them to use the imprecise and common term "lacquer thinner" to describe the latter product. If it is, indeed, isopropyl alcohol, then it will thin most non-synthetic lacquers.

So why use lacquer thinner at all? Isopropyl is cheaper and can be had in any (US) drug store. Lacquer thinner often contains (it can contain anything) other, much more noxious solvents that are also aggressive to plastic. Using such a solvent, to me, indicates an unwillingness to learn to use a material properly. When you mistreat a material, sooner or later it bites back.

Contra stultitia, deos ipsos se frustra contendere. Quare ergo me?

My container of Tamiya lacquer thinner says it contains the following:

Ethylene glycol monobutyl ether and methyl isobutyl ketone.

It is likely the very same stuff that's in their basic putty, because it smells the very same and it mixes very well with it. I also use it to thin "real" lacquers, like Alclad, Krylon, etc. with no issues and it cleans my paint brushes when ordinary paint solvent won't. Although it is safe for plastics, it does bite a bit and will leave the surface a bit rough. Tamiya calls it "a diluted lacquer thinner".

Edited April 29, 2014 by chuck540z3

[Thommo]

Tamiya and Gunze are very similar to each other, so you should be OK mixing them. MM Acryl, on the other hand, does not do its best when thinned with Tamiya thinner.

I used Tamiya Thinner on everything and it seems to work OK, even with MM Acryl. I had the old MM pouch paints which I've since decanted into jars. Though have not tried it with the Vallejo yet....sounds like I should not. Think instead of using neat Windex for the Vallejo, I'll try 50/50 Windex/distilled water next. And use my respirator mask this time !!!!

You've got me wondering now if the stuff I'm using is the Tamiya acrylic thinner (that's what I thought it was) or the Tamiya Lacquer thinner? Pretty sure it is the acrylic thinner, as it seems to work with the following acrylics - Tamiya, Gunze, MM, Citadel?

Sometimes I use Alclad (either neat or thinned with Humbrol enamel thinner), and very occasionally Humbrol enamels (thinned with Humbrol enamel thinner or turps).

[mossieramm]

And just to complicate things, I've found plenty of websites where people recommend using Windex to thin Vallejo paints.

Also to complicate things even further. I've had good results thinning Vallejo with plain water with a drop of washing up liquid, both for hand and airbrushing. Although the washing up liquid is not really neccesary when brush painting. A tip I got from this site.

David.

[Joel_W]

Tamiya acrylics are Alcohol based. Vallejo, Italeri, and Model Master acrylics are water based. They aren't compatible, and will separate if mixed together and form a jell like mess in your air gun.

Tamiya X20-A (white cap) is alcohol based, and contains a retarder. Tamiya's Lacquer Thinner (yellow cap) is a mild lacquer base with a retarder, that is safe for use on plastic. I use both depending on the job at hand. The Lacquer thinner breaks down the acrylic particles to a finer consistency then the X20-A does. As Chuck said, the drying time is a lot less, and the finish is a lot harder.

When air brushing Tamiya Acrylics with their lacquer thinner, I do so only in my paint booth as the fumes are an issue. Clean up is with lacquer thinner only, which also has it's odor issues.

Using Windex-D (Ammonia base) with a water based paint does indeed work, but isn't the best option as a thinner. Vallejo thinner works the best for both Vallejo and Italeri paints. Distilled water is also acceptable, but when you lower the psi, and move in really close for fine work, sometimes you get spidering from the water separating from the paint mixture. Using a retarder with both brands of paint is a must as they dry to fast for use with an air gun.

Joel

[Kaibutsu]

Tamiya acrylics are Alcohol based. Vallejo, Italeri, and Model Master acrylics are water based. They aren't compatible, and will separate if mixed together and form a jell like mess in your air gun.

Using Windex-D (Ammonia base) with a water based paint does indeed work, but isn't the best option as a thinner. Vallejo thinner works the best for both Vallejo and Italeri paints. Distilled water is also acceptable, but when you lower the psi, and move in really close for fine work, sometimes you get spidering from the water separating from the paint mixture. Using a retarder with both brands of paint is a must as they dry to fast for use with an air gun.

Joel

Thanks for the advice, Joel & everybody else!

[huntermountain]

I've tried all sorts of stuff with Vallejo. Water works, but I think some unexpected results were because of using normal tap water so I stopped doing that. Best results I had were with either Vallejo thinner or Vallejo airbrush cleaner. I did use Vallejo model air. Strangely enough, I had the least problems with paint drying on the tip of the airbrush when I thinned paint from the Model range, when I didn't have the right Model Air Colour. I never tried Isopropyl(I think it's called Isopropanol over here) because it's not that easy to get hold of.

Anyway, when I first got my hands on a jar of Tamiya acrylics, I put Vallejo model air in a drawer way at the back of my workbench, and I bought me a bunch of the Tamiya jars. Suddenly paint clogging the tip of the airbrush is no longer an issue, cleaning my airbrush is a breeze, and I really enjoy airbrushing. To be totally honest, I've bought all my Vallejo paint at the same store over a few years. Maybe the stuff just sat in the shop for to long, or the storage conditions weren't ideal? Who knows. Vallejo is great stuff to brush paint, but I won't be using it in my airbrush again any time soon...

[nmRoberto]

Can anyone guess what happened when I mixed Model Master acrylic with some Tamiya acrylic, then tried to spray it?

Nothing I like better than spend what seemed like forever trying to get the glorp out of my air brush. Oh well....live and learn.

[Joel_W]

Can anyone guess what happened when I mixed Model Master acrylic with some Tamiya acrylic, then tried to spray it?

Nothing I like better than spend what seemed like forever trying to get the glorp out of my air brush. Oh well....live and learn.

As I said early, one is an alcohol based and the other a water based. The result is a completely clogged air brush that will take forever to clean. I hope that you took it completely apart, and cleaned each piece with Lacquer Thinner. Then after re-assembly, shoot Lacquer thinner though it to make sure it sprays correctly and smoothly.

Joel

[nmRoberto]

As I said early, one is an alcohol based and the other a water based. The result is a completely clogged air brush that will take forever to clean. I hope that you took it completely apart, and cleaned each piece with Lacquer Thinner. Then after re-assembly, shoot Lacquer thinner though it to make sure it sprays correctly and smoothly.

Joel

Wish I had read your post before mixing the two paints together.

And yes, I completely stripped the air brush and cleaned everything out. It works fine now.

I did learn an important lesson, I'm never going to try to mix different brands again.

[galileo1]

Well, to further complicate things, I've thinned Vallejo Model Air with Tamiya's X20A acrylic thinner (white cap) and I was shocked, literally shocked, at how smooth the paint came out of the airbrush. No tip drying or clogging of any kind. It was the first ever time I've actually enjoyed spraying Vallejo. Go figure...

Rob

[Thommo]

Tamiya acrylics are Alcohol based. Vallejo, Italeri, and Model Master acrylics are water based. They aren't compatible, and will separate if mixed together and form a jell like mess in your air gun.

Tamiya X20-A (white cap) is alcohol based, and contains a retarder. Tamiya's Lacquer Thinner (yellow cap) is a mild lacquer base with a retarder, that is safe for use on plastic. I use both depending on the job at hand. The Lacquer thinner breaks down the acrylic particles to a finer consistency then the X20-A does. As Chuck said, the drying time is a lot less, and the finish is a lot harder.

When air brushing Tamiya Acrylics with their lacquer thinner, I do so only in my paint booth as the fumes are an issue. Clean up is with lacquer thinner only, which also has it's odor issues.

Using Windex-D (Ammonia base) with a water based paint does indeed work, but isn't the best option as a thinner. Vallejo thinner works the best for both Vallejo and Italeri paints. Distilled water is also acceptable, but when you lower the psi, and move in really close for fine work, sometimes you get spidering from the water separating from the paint mixture. Using a retarder with both brands of paint is a must as they dry to fast for use with an air gun.

Joel

Well, I mixed Vallejo & Tamyia acrylic again last night (no choice if I wanted the correct colour), but this time instead of using neat Windex as thinner, I used 50/50 Windex/distilled water and aimed it at my model :blink:/>/> . It did not form a jell mess, but did not spray as well as when I did this with just neat Windex as the thinner. A lot more tip clogging and very difficult to get a fine line. It seems to have dried OK, but a bit too thick (the pre-shading has been obliterated).

I tend to agree with the posts above however, Vallejo Colour through the airbrush is far trickier than Tamiya. I'm reverting back to Tamiya for the rest of this build. And I do have the right Tamiya thinner (white cap = acrylic).

And I'm hoping the LHS gets their new Tamiya stock in soon!

Actually, to be fair, the Vallejo might be fine if I had the right thinner and did not mix it with Tamiya.......

Edited April 29, 2014 by Thommo

[Triarius]

I'm going to get some of the Tamiya products and see if I can figure out something about their composition. Wish I still had access to a lab.

[RichardL]

Here is a pic showing the composition of Tamiya Lacquer Thinner:

It doesn't look like isopropyl alcohol to me. I can work with 91% alcohol all day long without getting nauseous. One whiff of this stuff, on the other hand, would make me light headed shortly after, which means it's more potent than your ordinary isopropyl alcohol.

[Triarius]

Thank you Richard! :thumbsup:/>

That doesn't look like isopropyl alcohol to me, either. However, it may contain it

I thought Tamiya might have sent me the wrong MSDS. They didn't. That MSDS is inaccurate, the label information indicates that this is not proprietary composition, and therefore has to be disclosed on the MSDS as well as the product label. If the EPA or OSHA finds out about it, Tamiya USA may be in trouble.

Here are links to the two components mentioned on the label:

ethylene glycol monobutyl ether : this is from Dow Chemical Company

methyl isobutyl ketone : this is from the EPA

[Joel_W]

Well, to further complicate things, I've thinned Vallejo Model Air with Tamiya's X20A acrylic thinner (white cap) and I was shocked, literally shocked, at how smooth the paint came out of the airbrush. No tip drying or clogging of any kind. It was the first ever time I've actually enjoyed spraying Vallejo. Go figure...

Rob

Rob,

That's very interesting. I just go with what the base of the paint is. Thinking about it, X20-A is alcohol based, but it does contain distilled water. So I'm thinking that it will thin water based paints. Just don't mix those base paints together.

Joel

Edited April 30, 2014 by Joel_W