I didn't know that either.......... 

I've only painted 6 models with a paint brush, all of them using Tamiya acrylics and i didn't even thin the paint as i only started using thinner when i bought my first airbrush/compressor set. 
What i can say about brushing Tamiya acrylics is the same you guys have already said, give it enough time to dry for a second coat or do it in one go.
There's one thing that really helps with the issue of the paint coming off with a second coat and that is to clean every part very well cause if there's any evidence of finger grease or dust, it will happen even when the undercoat is dry but, the best thing is really not to mess with it too much after a coat is on.
I've had stuff that was cleaned with IPA before painting and that did seem to help with the paint sticking better when brush painted.
Regarding thinners, i only use IPA, X-20A or the famous Unicorn tears, AKA Mr. color levelling thinner and, if anyone's in doubt, this thinner seems like it really works magic on the paint, at least for airbrushing. The paint seems to come out smoother and doesn't dry on the tip of the needle as easily. I believe it should also make a difference when it's brushed on but i haven't tried it yet. I normally just dip the brush in the pot and paint cause most of the stuff is the smaller stuff in the cockpits and interior bits that won't be easily seen.

I'm sorry but every time I see IPA written down my brain goes Indian Pale Ale  certainly no use in thinning paint but probably thins my brain 

Quote from: NARSES2 on September 12, 2022, 05:54:41 AMI'm sorry but every time I see IPA written down my brain goes Indian Pale Ale  certainly no use in thinning paint but probably thins my brain 

Same here
 

Have you not heard of this stuff? It works great for hand and air brushing.





Chris

In a word, 'No'. How do you use it?

Quote from: PR19_Kit on September 14, 2022, 02:35:05 AMIn a word, 'No'. How do you use it?

I've not seen it in the UK either although it could be that some Japanese, in particular, paint/glue/thinners fell foul of EU and thus UK legislation.

Quote from: NARSES2 on September 14, 2022, 05:09:39 AM

Quote from: PR19_Kit on September 14, 2022, 02:35:05 AMIn a word, 'No'. How do you use it?

I've not seen it in the UK either although it could be that some Japanese, in particular, paint/glue/thinners fell foul of EU and thus UK legislation.

I have heard that Windsor and Newton Flow Improver does a better job and is available in Hobbycraft, The Range and good artist shops.

You mix a small drop with your paint and it acts as a thinner. It also keeps the paint liquid for longer.

QuoteWindsor & Newton Professional Flow Improver
This additive increases the flow of acrylic colours, by breaking down the surface tension of the water. It is ideal for the application of areas of flat and even colour without changing colour strength. It is also effective for hard edge painting techniques, staining and water colour techniques. It maintains the stability of the colour and slightly slows drying, so colours will remain usable slightly longer when mixed with this medium.

If you want to dilute your colour significantly, we recommend using Flow Improver with your water, as this preserves the integrity of the paint film, ensuring the pigment remains sufficiently bound. Under-bound colour can appear blotchy, may become brittle or not adhere to the canvas well, all issues which are avoided if you use Flow Improver. This additive maintains no colour shift from wet to dry when used with Winsor & Newton Artists' Acrylic.

Vallejo, AK Interactive and Mig have acrylic retarders/extenders/flow improvers that should work with Tamiya (I can try it). They're probably just repackaged Golden (or similar brands) acrylic retarders.

You don't need much - in fact, too much will just make the paint unusable.

I know some folks us oil paints for weathering but does anyone use it for painting in general? I'm thinking right now of small parts like landing gear and weapons that I tend to brush paint. Enamels and acrylics seem to leave everything goopy and cover up details. I wonder if oils would work better.

As I recall, the problem with oils is they take a while to dry, and I don't know what the thinners would do to plastics & whatnot.

What about craft acrylics, the type in tubes? They're pretty cheap, can be thinned and washed out in water, and dry quickly and hard.
And you can thin them down to a wash and use multiple coats to buld up the colour without filling in detail.