Tamiya paint problems

Need some more information, first:

1. How old is the paint?
2. Flat or gloss?
   
3. What are you using as a reducer (thinner)?
4. What dilution ratio are you using?
5. Are you using an acrylic retarder?
6. What kind of airbrush are you using?
7. What air pressure are you using?
8. How far from the model surface are you spraying?

Graininess usually means you are too far away, using too much pressure, or the wrong reducer to thin the paint. All of these things cause the paint to start to dry before it reaches the model surface, resulting in the texture you describe.

Be sure not to spray from too far away.  If you thin with alcohol, the paint dries very quickly, especially when spraying from a distance.  Tamiya thinner has a mild retarder in it that slows down the drying process and can help with getting a smoother finish.

The above posts are applicable if you are airbrushing. If you are brush-painting, then thats a different ballgame.

The current formula for Tamiya acrylics are notorious for "roll-up" when brush painting. This occurs because the paint "skins over" very quickly and when you brush over a previously covered area, it drags up the previously applied layer of paint. This happens more readily when you paint "out of the bottle" without thinning. To reduce this effect, don't brush paint straight from the bottle. Instead, pour a little of the paint into a pallette and add some thinner. If you're using an alternative thinner, add a drop or two of acrylic retarder to your paint mix  ("genuine" Tamiya thinner is said to contain a retarder). Acrylic retarder can be found at your local art supplies store.

Tamiya's acrylics also seem a bit fussy about what brush you use. They seem to work best with brushes which are soft, but with a little "body". I have tried some "too soft" brushes which leave a grainy, shiny-speckly effect, yet firmer brushes will work just fine for the same bottle of paint.

Phil_H.

And that's not just the current formulation—I have "old" (circa 1980's) Tamiya paints that behave the same way. Also, be careful of the retarder—some old Tamiya,  at least, doesn't like larger doses.

I found Tamiya acrylics from the early-mid 80's very good. In some cases you needed to look closely so see that it was brush painted and not airbrushed (flats in particular, though I used to get great results using gloss white over white plastic too). You could almost just slop it on and it levelled out beautifully. Then it began to change. I'm not sure exactly when, but I'm guessing around '88 or so.

Early Humbrol acrylics from the same era (the ones in the little white plastic pots), well, thats another story. Crud.. no other way to put it. If you didn't like the paint job, you could just let it dry and then peel it off in sheets.

what I do is start with an empty 1/2 ounce jar (ex-Pollyscale/Warbird/Testors Acryl) and add two pipettes worth of Tamiya thinner (you need the retarding agent in it) and add almost the whole bottle (the mini bottle that is) of paint leaving just  a little room in the top for the the paint strainer/filter.

(I use an in-line paint filter on my Badger 350F, it prevents clumps of paint from blocking the tip)

the retarding agent in Tamiya thinner helps keep the tip from clogging and helps keeps the paint flowing so I get more painting done and less time cleaning the tip.

as for brushing by hand with  a paint brush...I've only done that once (and one with Gunze) and it was a disaster that I will not repeat.

in short use Tamiya and Gunze ONLY in your airbrush !

EDIT : I mixed some gloss white (X-2) with some X-5 Green and used it to paint-by-hand with a brush and found it to be quite excellent.

I'm beginning to think that there is something in the flat paints that isn't in the gloss paints and that is our culprit

I found Tamiya acrylics from the early-mid 80's very good. In some cases you needed to look closely so see that it was brush painted and not airbrushed (flats in particular, though I used to get great results using gloss white over white plastic too). You could almost just slop it on and it levelled out beautifully. Then it began to change. I'm not sure exactly when, but I'm guessing around '88 or so.

Amen to that. I used to know a guy who brush painted cars with Tamiya and got very good results. I used it extensively back then. Airbrushed with water as a thinner and got excellent results, including one of my firts regional awards, a 1/6 motorcycle. The "new" formula is just too quirky and requires way more work that any other paint to get an acceptable finish with brush or airbrush.

You know, I've been experimenting with brush painting Tamiya Acrylics lately and have found that I get better results if I add a little bit of Tamiya thinner.  I take soda bottle caps, or beer bottle caps, mix up my paint and add it to a little bit of the thinner in the cap and brush away.  I've found that the paint flows better, doesn't dry as quickly (due to the drying retardant in the thinner) thus helping to prevent brush marks and keeps the paint from being too thick for brushing.  This also allows for a longer brush painting session as the paint doesn't thicken up quite as fast in the cap.

Instead of having to find a bottle cap all the time for a palette, I have found these type palettes from Michael's Art store and others to be great! They clean up easy with a paper towel and some Windex. 

This is like the one I have. They also come in aluminum. 

 

MikeV wrote:

Instead of having to find a bottle cap all the time for a palette, I

There never seems to be a shortage of bottle caps in my house...

espins1 wrote:

MikeV wrote: Instead of having to find a bottle cap all the time for a palette, I There never seems to be a shortage of bottle caps in my house...

I hear you bro.