What effect is this (Humbrol acrylic + Tamiya thinner)

[Tomathee]

As title really. Each time I add Tamiya acrylic thinner to Humbrol acrylic paint I get this happen. The paint is shaken and stirred well, has usually had flow enhancer added and stirred in beforehand, any ratio that I've used. I add the thinner to the paint, stir with a cocktail stick or coffee stirrer, looks fine for 30 seconds to a minute then goes like this. I've carried on painting with it, either as is or stirring the top without sticking the whole brush in before taking it and it hasn't seemed to have any ill effects. Just wondered if it's a known incompatibility kind of issue or if I should take a step to avoid it, have swapped to thinning them with water in the meantime.

[Bonhoff]

TBH I tend to find Tamiya thinner only seems to work with Tamiya and Gunze paints.

Tam thinners and Vallejo paints just result in a gummy mess, Humbrol IMHO seems to behave the same way.

Better with Vallejo Thinners or tap water.

Other people may have different experiences.

[Black Knight]

Non-mixing.

Tamiya acrylic is lacquer based

Humbrol is water based

Oil and water do not mix

[fewr9fkr9595]

⬆️ But you can thin tamiya with water...

[wyverns4]

Your image strongly suggests immiscibility. Thus the two liquids are not compatible.

I would try something else as suggested by Bonhoff.

Tamiya can be thinned with water, but that is a result of the chemical constituents that make up the pigment and carrier. It would be unlikely that Tamiya would have formulated their paints for mixing with other, non-Tamiya paints and additives.

HTH!

Christian, exiled to a land without hobby paints

[Dave Fleming]

Non-mixing.

Tamiya acrylic is lacquer based

Humbrol is water based

Oil and water do not mix

Tamiya acrylic is not lacquer based. If it was, it wouldn't be water cleanable. It uses various alcohols as it's thinner. You can thin it with lacquer.

[John]

I use a few drops of Tamiya thinner with Humbrol acrylics all the time and I've never had a problem with the finished surface. In fact, I find it's quite an effective combination. I get through quite a lot of Tamiya thinner even though I've only got a couple of Tamiya paints!

John

[Tomathee]

Thanks for the replies, always good to see a bit of discussion on a thread. Seems clear that Tamiya thinner isn't suitable for a lot of other brands, now I'm wondering whether it's even worth getting one to suit the other paint brands I have (so far I've encountered Revell, Humbrol, Xtracrylix and Vallejo), or just forgetting it and using water. As I can think of several dozen things I'd rather buy than the accompanying thinner for each brand maybe I should look at something like ultimate airbrush thinner as an all rounder (even though I'm brushing, first example that came to mind and I'm sure it works the same).

[Black Knight]

I keep Tamiya thinner for Tamiya only and use water for Humbrol, Revell, MP, Vallejo and a couple of other acrylics