Thinning Gunze Acrylics

[Mike C]

Wow, FOUR layers. How long did you have to wait between layers?

Just long enough for the paint to dry to touch, usually an hour or two. This is why I prefer using methylated spirit (denatured alcohol), because the paint dries quicker.

[JackMan]

Not so much the drying time, but the curing time. Gunze gloss and semi-gloss acrylics remain soft (and therefore not fully cured) for quite some time after they become touch dry. In fact, if the paint is old, not mixed properly with the thinner, or an inappropriate thinner used, it can take a week or more to fully harden. Using Windex as a thinner with these paints seems to slow the cure time, especially compared with something like denatured alcohol (methylated spirits in my case). I just don't think there's any real advantage to using Windex, even though it works.

Kev

No wonder! I thought there was something wrong with the way I was doing things. Now I know it's the nature of Gunze. Thanks, Kev

Just long enough for the paint to dry to touch, usually an hour or two. This is why I prefer using methylated spirit (denatured alcohol), because the paint dries quicker.

Ok, will give methylated spirit a try. Thanks for the advice, Mike

[Big Kev]

Thanks, Kev

You're welcome!

Kev

[Mike C]

Ok, will give methylated spirit a try. Thanks for the advice, Mike

JackMan, make sure you test spraying on scrap piece first! I doubt that methylated spirit has the exact same formulation worldwide. What you get where you are may have completely different formulation from the one I've got here in Aust, and may exhibit completely different characteristics when used to thin Gunze Aqueous.

[toadwbg]

The "layer" thing got brought up again. While this is an approach, stretch your mind and wrap it around the misting concept. Misting is building up the layer where and as needed i'n usually a single session. Doing this requires the right conditions where you see the paint locally dry to the touch i'n front of your eyes.

[Paolo Maglio]

I use Mr. Colour Laquer thinner or Tamiya Laquer Thinner.

Both work perfectly with Gunze and you can achive a very smooth and hard surface.

With X-20 I had bad experience in the past since drying time was too long and paint would melt again adding decals solution.

With denaturated alcohol which I used for 20 years finish was not good especially with glossy colours.

[JackMan]

A report:

Last evening I was back on the "AB newbie learning curve"..

For thinners, I only had Tamiya X-20 & Windex as I didn't have time to go to the shops for denatured alcohol or Gunze's thinner . My new ABs which I'm trying to break into are a Badger Patriot 105 & a Tamiya Super Fine (Iwata clone, tailor made for Tamiya 1/72 warbird collection, I believe).

Gunze with Tamiya X-20A

I first tried Gunze Aqueous FS36375 thinned roughly about 60/40 or 50/50 with X-20A on a test plane. I tried the misting method suggested by toadwbg on the port tailplane of testplane:

I was initially annoyed by the pebbly surface that misting resulted in but continous misting by moving the hand side to side resulted in a smoother finish. I liked it & I was surprised that the finish was pretty flat.

Then I tried a bit more on the starboard tailplane but this time I didn't mist so much and tended to hold the nozzle at a particular point a little longer. As a result, the paint "pooled" slightly at the leading edge of the tailplane. I painted mainly the leading & trailing edges (ignore the purple Tamiya paint in the centre...the result of an earlier paint trial..):

Gunze with Windex

Again Gunze Aqueous FS36375 but thinned roughly about 60/40 or 50/50 with Windex.

It went on smoother than with X-20A. The mixture also felt more "watery" in the AB cup.

I found that Gunze with Windex dries faster than Gunze with X-20A. I believe I read somewhere that it's because X-20A has a mild retarder and this slows the drying time. Here's a pre-shaded 1/72 Fujimi Phantom that I also painted Gunze FS36375 + Tamiya X-20A long before I tried the Gunze/Windex mixture:

It went on smooth but even after leaving it to dry for about 35 mins, the paint still felt 'soft' to the touch (which resulted in a fingerprint or two on the fuselage

In contrast the Gunze/Windex mixture dried in about half that time.

One thing I learned from this experience is that the Badger Patriot 105 takes some getting used to. The trigger feels a bit heavy & 'sticky' and I sometimes end up applying too much finger pressure on the trigger resulting in too much paint coming out too fast (hence the paint pooling in my starboard tailplane above)

In contrast, the Tamiya SF trigger feels more intuitive in your hands. It feels smooth when you press & pullback (dual action) on the trigger. The Patriot feels....slightly jerky. Takes some getting used to, I guess.

In concussion :wacko:

The way Gunze Acrylics lays on your subject depends a lot on

1) The thinner that you use

2) The airbrush that you use

3) how much pressure you're using

4) Maybe other factors that I've yet to discover... :blink:

[toadwbg]

Outstanding work Jackman. You have taken your first step into a larger universe!

[Mike C]

Great stuff!! Keep it up, and you'll be a master in no time at all!

Then I tried a bit more on the starboard tailplane but this time I didn't mist so much and tended to hold the nozzle at a particular point a little longer. As a result, the paint "pooled" slightly at the leading edge of the tailplane.

I think this is a big "no-no" in airbrushing. From what I learned from this forum and personal experience, the key to airbrushing is to make continuous sweeping motion across your "victim".

One thing I learned from this experience is that the Badger Patriot 105 takes some getting used to. The trigger feels a bit heavy & 'sticky'

Hmmm... That's not good. Sticky trigger makes it hard to control the paint flow, I think. I've only ever used "el cheapo" airbrush bought from eBay. Their trigger is pretty good (dual-action, gravity-fed).

[galileo1]

A report:

Last evening I was back on the "AB newbie learning curve"..

For thinners, I only had Tamiya X-20 & Windex as I didn't have time to go to the shops for denatured alcohol or Gunze's thinner . My new ABs which I'm trying to break into are a Badger Patriot 105 & a Tamiya Super Fine (Iwata clone, tailor made for Tamiya 1/72 warbird collection, I believe).

Gunze with Tamiya X-20A

I first tried Gunze Aqueous FS36375 thinned roughly about 60/40 or 50/50 with X-20A on a test plane. I tried the misting method suggested by toadwbg on the port tailplane of testplane:

I was initially annoyed by the pebbly surface that misting resulted in but continous misting by moving the hand side to side resulted in a smoother finish. I liked it & I was surprised that the finish was pretty flat.

Then I tried a bit more on the starboard tailplane but this time I didn't mist so much and tended to hold the nozzle at a particular point a little longer. As a result, the paint "pooled" slightly at the leading edge of the tailplane. I painted mainly the leading & trailing edges (ignore the purple Tamiya paint in the centre...the result of an earlier paint trial..):

Gunze with Windex

Again Gunze Aqueous FS36375 but thinned roughly about 60/40 or 50/50 with Windex.

It went on smoother than with X-20A. The mixture also felt more "watery" in the AB cup.

I found that Gunze with Windex dries faster than Gunze with X-20A. I believe I read somewhere that it's because X-20A has a mild retarder and this slows the drying time. Here's a pre-shaded 1/72 Fujimi Phantom that I also painted Gunze FS36375 + Tamiya X-20A long before I tried the Gunze/Windex mixture:

It went on smooth but even after leaving it to dry for about 35 mins, the paint still felt 'soft' to the touch (which resulted in a fingerprint or two on the fuselage

In contrast the Gunze/Windex mixture dried in about half that time.

One thing I learned from this experience is that the Badger Patriot 105 takes some getting used to. The trigger feels a bit heavy & 'sticky' and I sometimes end up applying too much finger pressure on the trigger resulting in too much paint coming out too fast (hence the paint pooling in my starboard tailplane above)

In contrast, the Tamiya SF trigger feels more intuitive in your hands. It feels smooth when you press & pullback (dual action) on the trigger. The Patriot feels....slightly jerky. Takes some getting used to, I guess.

In concussion :wacko:

The way Gunze Acrylics lays on your subject depends a lot on

1) The thinner that you use

2) The airbrush that you use

3) how much pressure you're using

4) Maybe other factors that I've yet to discover... :blink:

Did you try spraying your mix (Gunze + Windex) over any previously applied coat of acrylic paint? Or was the test done on bare plastic (sorry, can't exactly tell from the pics)? If you applied your mix over an existing acrylic coat, did you notice any adverse effects afterward? I'm just curious as I might want to give this a try....

Thanks,

Rob

[Chuck1945]

Use Windex to clean your airbrush, not to thin paint. :) Windex contains ammonia which can be a pretty effective solvent on acrylic paints (that is why it makes a great cleaner after spraying acrylics). Gunze Aqueous (and Tamiya) paints are formulated to use alcohol as the thinner, Isopropyl alcohol is the major ingredient in Tamiya's X-20A.

Also adding to toadwbg, well done to discover the misting process. Misting a very light coverage allows to keep re-spraying without having to actually stop painting to allow a 'too heavy' coat to dry and you can build up your coverage all in one go.

[JackMan]

Did you try spraying your mix (Gunze + Windex) over any previously applied coat of acrylic paint? Or was the test done on bare plastic (sorry, can't exactly tell from the pics)? If you applied your mix over an existing acrylic coat, did you notice any adverse effects afterward? I'm just curious as I might want to give this a try....

Thanks,

Rob

Hi Rob,

The Gunze+Windex mixture was painted on bare plastic (the plane with the red tail in my picture). The Gunze+X-20A ,however, was painted over a base of Tamiya Acrylic purple & black. Earlier I had used these Tamiya paints to test the airbrushs on the test plane a couple of days earlier & so I decided to see what Gunze+X-20A will be like over a base coat.

So,

1) No adverse effects for Gunze+X-20A over Tamiya Acrylics.

2) Not sure about Gunze+Windex over Acrylics. But might give it a try next week when I get back to AB-ing ( a little busy to break out the AB for the rest of this week :) )

[JackMan]

Thanks so much for the encouragement & advice guys! Much appreciated I'll be sure to bug you guys more as I go through further learning process. :lol:

Okay, so last evening after work I had time to go to the nearest pharmacy & get the following.

The 3 Amigos. From left to right: Denatured Alcohol (95%), Isopropyl Alcohol(70%) & Methylated Spirit (96%).

Next week, I'll be using each of the 3 Amigos :lol: as thinners to see which one works best for me. I fully expect the results to be different for each AB (since the Tamiya Superfine AB has a smaller nozzle (0.2mm) compared to the Patriot 105). I think the size of the paint pigments of each type of acrylic will affect how it comes out of the different nozzle sizes.

Since I'm switching from handbrushing enamels (Humbrol & MM) to airbrushing acrylics (largely because of the smell & ease of AB clean-up), I'm currently trying out 3 different acrylics: Gunze, Tamiya & Xtracrylix. Of the 3, Tamiya has so far been the most user-friendly. Unfortunately, Tamiya's range of colours is a little limited when compared to Gunze. I really want Gunze to work out as I've heard SO many good things about it and because of it's larger range of colours.

Xtracrylics is a whole different story. I bought a bunch of these when TwoBobs was having a clearance sale. Their range of colours (esp the Luftwaffe RLM ones) is impressive. But when used, they have a tendency to clog up your AB nozzle. A quick read in the Britmodellers forums tells me that I'm not alone. The clogging really surprised me as...when pouring the stuff out into my AB cup...I found it to be thinner & more watery than my Gunze/Tamiya/Thinner mixes. It also sprays on VERY thin and you definitely need a base coat (otherwise the paint will 'run' on bare plastic---in sharp contrast to Tamiya which lays down beautifully). The biggest headache was cleaning it from the AB. The stuff just won't clean with either water, Windex or X-20A. Sure, it cleans somewhat, but you still find the paint residues stuck inside the cup & nozzle tip. You have to literally scrap it off with a toothpick (nerve-wrecking; given how fine the Tamiya SF tip is ). I think it's better suited for brush-painting. Will try thinning with the 3 Amigos & see how it goes.

I have also ordered some Lifecolor paints & am waiting for them to arrive. I'll be experimenting with those too. For now, my main focus will be on Gunze. Because their range of colours is better & also because most of my kits are either Hasegawa or Fujimi & their colour call-outs are in the Gunze range. Will post the "3 Amigos Thinner Test" results next week. Hope others find these posts useful

[Mike C]

The 3 Amigos. From left to right: Denatured Alcohol (95%), Isopropyl Alcohol(70%) & Methylated Spirit (96%).

From what I read on this forum, denatured alcohol was supposed to be the same as methylated spirit. So, I find it quite interesting that you can get both where you are there, with what appears to be different ingredient?

Tamiya has so far been the most user-friendly. Unfortunately, Tamiya's range of colours is a little limited when compared to Gunze. I really want Gunze to work out as I've heard SO many good things about it and because of it's larger range of colours.

Tamiya is definitely fantastic to spray, especially their XF (i.e. flat range). In my experience, Gunze is virtually identical. I even often mix both paints. So, I'm quite surprised that your experience seems to differ so much.

I have also ordered some Lifecolor paints & am waiting for them to arrive. I'll be experimenting with those too.

I have a feeling that you won't like LifeColor that much. :lol: It's quite thick. I started using it recently. Personally, I'm still not that used to it. When thinned then sprayed, it's waaay too runny for my liking. I use distilled water to thin. At first I thought it was because I used distilled water, but then an LHS employee told me that he used LifeColor's thinner and didn't see any difference. I have also tried thinning with X-20A, and got mixed results. Sometimes it's good, other times it's lumpy and clogs up the AB.

Edited June 23, 2011 by Mike C

[Big Kev]

From what I read on this forum, denatured alcohol was supposed to be the same as methylated spirit. So, I find it quite interesting that you can get both where you are there, with what appears to be different ingredient?

Methylated Spirits is actually a form of denatured alcohol. They call it 'denatured' alcohol because they add stuff to it that induces vomiting if you try to drink it. What the specific difference is between methylated spirits and anything labelled 'denatured alcohol', I have no idea.

By the way, metho have very similar thinning characteristics with Gunze and Tamiya acrylics as X-20A, except that it dries a lot faster. Not recommended for hot, dry climates!

Kev

[Mike C]

By the way, metho have very similar thinning characteristics with Gunze and Tamiya acrylics as X-20A, except that it dries a lot faster. Not recommended for hot, dry climates!

Been working quite OK for me, even in summer. I guess the ducted evaporative cooling helped....

[Big Kev]

Been working quite OK for me, even in summer. I guess the ducted evaporative cooling helped....

Yeah, normally Melbourne's climate isn't hot enough or dry enough to bother the process. I often find that using metho during the winter helps to combat naturally slower drying times, whereas using X-20A in the summer helps combat unhelpfully fast drying times!

Kev

[Mike C]

Yeah, normally Melbourne's climate isn't hot enough or dry enough to bother the process. I often find that using metho during the winter helps to combat naturally slower drying times, whereas using X-20A in the summer helps combat unhelpfully fast drying times!

Kev

I guess that explains why using X-20A lately made my paint much more runny.

[JackMan]

Sorry I couldn't post this sooner as promised earlier. Life just got in the way :)

Report No II

To refresh, the 3 Amigos:

From left to right: Denatured Alcohol (95%), Isopropyl Alcohol(70%) & Methylated Spirit (96%)

For this test, I decided to use 3 x identical forward fuselages from the 1/72 Hasegawa F-4EJ Kai kits. I sprayed the interiors because it's easier to cover up any screw-ups. The colour used is Gunze FS36320 (Dark Ghost Grey). This time I used the Tamiya SF airbrush instead of the Badger Patriot. The mixing ratio for each thinner was initially 50:50. But then the mixture laid down with a pebbly texture. So I tried 70:30 & 60:40 and had much better & smoother results. Please note that if the pictures of the fuselage interiors looks 'rough', it's not because of the paint but the plastic itself. The paint actually goes on smoother in reality than what can be seen in the pictures. I also did the tests on a different test subject with a different plastic (smoother than the Hase interiors) & got the same results.

Amigo No.1: Denatured Alcohol (95%)(DA)

I liked this mixture the best. Smooth, dries fast and easy to handle.

Amigo No.2: Isopropyl Alcohol (70%) (IA)

I didn't like this mixture so much. The paint had a tendency to dry up quicker at the nozzle and landed with a pebbly surface. It also seems more difficult than the other two to come out of the nozzle.

Amigo No.3: Methylated Spirit (96%) (MS)

This one had a similar result & feel to the denatured alcohol (DA). This jives with what Kev wrote earlier: "Methylated Spirits is actually a form of denatured alcohol". However, I somehow felt that the DA mixture goes on slightly better than the MS. MS also seems to have the fastest drying time & yet doesn't dry too fast like the IA mixture.

Some observations:

1) I noticed that when thinning Gunze with any of the 3 Amigos, I needed to have a slightly higher AB pressure: around 15-17 PSI in order for the mixture to come out smoothly. In my previous test with Tamiya X-20A & Windex, it was around 10-12 PSI. I'm not sure if this was because I was using a smaller nozzle (Tamiya SF is 0.2mm) than the previous test (Badger 105) or because of the different properties of X-20A & Windex when compared to the 3 Amigos.

2) Chuck1945 & Big Kev were right. Windex is best used as a cleaner than a thinner. This stuff is great! It even managed to dislodge some dried Xtracrylic chips that were lodged in a hard-to-get-at place in the airbrush.

3) When it comes to thinning, I'm quite happy with Denatured Alcohol. A close second would be Methylated Spirit. Some might say the 2 are the same but I'm going by "feel" and I feel DA goes on better. Tamiya X-20A is also a good thinner as is Windex. But X-20A has a restarder which slows drying time. This might suit those of you who have a different climate but here in hot humid Asia where it's scorching hot 1 minute & a thunderstorm the next, the weather is unpredictable & I don't like the slower drying time or the 'icky' feeling you get when you touch the paint 30 mins later to see if it's dry. Not to mention the fingerprints you leave behind

4) It's good to have flexibility when it comes to your hobby tools & supplies. So if you've suddenly run out of Gunze's own thinner or Tamiya X-20A, you can always use DA or MS (and vice versa). A last resort will be Windex; also good as a thinner but better as a cleaner. For me, I'm sticking to DA from now on when it comes to Gunze Aqueous (Gunze Acrylics).

I hope these posts help others who, like me, are new to Gunze Acrylic paints

[Mike C]

Well done, mate!

Nicely written report. Very thorough. You deserve two :thumbsup:

[SERNAK]

Since this discussion has been mainly focused on the Gunze and Tamiya range of colours, I would like to ask something about their varnishes; both, the gloss and matt.

Do you follow the same rules when airbrushing both the colours and varnishes range? 2 parts varnish and one part thinner at 12psi? Or, do you follow different settings?

Many Thanks,

Sernak

[Chuck1945]

...I noticed that when thinning Gunze with any of the 3 Amigos, I needed to have a slightly higher AB pressure: around 15-17 PSI in order for the mixture to come out smoothly. In my previous test with Tamiya X-20A & Windex, it was around 10-12 PSI. I'm not sure if this was because I was using a smaller nozzle (Tamiya SF is 0.2mm) than the previous test (Badger 105) or because of the different properties of X-20A & Windex when compared to the 3 Amigos.

...

I use a H&S airbrush, and even using the 0.15mm needle/tip combination, I find properly thinned (with X-20A) Gunze (and Tamiya) will spray at 6-8 psi (for fine stuff such as a 1/72 Luftwaffe mottle) and using the 0.2mm needle/tip and 8-12 psi for general work. I suspect it may have been the slightly different properties of your '3 Amigos' rather than the airbrushes that necessitated the use of a higher pressure - either that or you needed to thin the paint more ;) For general work, I use 30-50% thinner and for finer stuff, 50-70%.

[Mike C]

Since this discussion has been mainly focused on the Gunze and Tamiya range of colours, I would like to ask something about their varnishes; both, the gloss and matt.

Do you follow the same rules when airbrushing both the colours and varnishes range? 2 parts varnish and one part thinner at 12psi? Or, do you follow different settings?

Many Thanks,

Sernak

You can use 2 parts varnish and 1 part thinner, but you'd have to use higher pressure, most likely around 15Psi (using gravity-fed airbrush). Or, equal part varnish and thinner at lower Psi (10-12). For 1st option, 1 layer might be enough, but 2nd option would require multiple layers. Personally, I've been using the 2nd option.

[JackMan]

Well done, mate!

Nicely written report. Very thorough. You deserve two :thumbsup:

Thanks Mike! I'm grateful for the tips & advice that you & the others have given.

Chuck, I think you could be right. It's probably the properties of the 3 Amigos & their mixing ratios rather than the airbrushes.

[Mike C]

Thanks Mike! I'm grateful for the tips & advice that you & the others have given.

No worries. We're all here to share and learn from each other.