Problem with Liquitex matt

Armor/AFV Painting & Weathering
1

Hi All. Ive tried using this brand of matt varnish but im getting a white film left on the paint surface. Questions:

What am I doing wrong, its diluted using distilled water, 50 then 30%.

Any ideas on how to remove the white gunk left behind.

Please see my M925 shelter truck for an example of the mess.

IMG_3450

2

Might have been too thin and puddled, since it doesn’t look like regular ‘frosting’ to me. For getting rid of it, another coat of gloss might work. Then you’d be all set to try again.

3

If you over-thin acrylic matt medium, it will dry with a frosty white finish. There needs to be a certain amount of the acrylic binder in the thinned solution to cover / coat all of the clear pigment particles, or the particles just stick to the surface and appear white.

It’s kind of like the effect of white snow. The individual snow flakes are really clear ice, but when piled up, they turn white. If you scoop a shovel full into a bucket of cold water, the snow turns into a clear mass.

At best, I’ve found artist matt medium can only be thinned down about 30% to get consistently clear results. At a thinning ration approaching 50-50 it’s common to start getting a white frosty look.

I use a lot of it as a light duty adhesive for small parts and diorama ground work, and I also add it to hobby acrylic paints, like Vallejo Model Color when thinning those paints for hand brushing. When used as a diorama texture / scatter adhesive, I don’t thin more than about 25-30%, and then I add a a flow aide / flow enhancer to mitigate beading up and as a wetting agent. As a light duty assembly adhesive, I use it straight. It works similarly to PVA but will dry dead flat. It’s also proof against most solvents, to include water, which will dissolve dried PVA and break the glue joint.

FWIW, I don’t use artist acrylic matt medium as a clear flat. (I personally use Testors Dull Coat, but if I was going to use an acrylic, I’d use a proprietary purpose formulated clear flat.) Artist acrylic matt medium, as a clear flat for art work is pretty much intended to use straight out of the bottle and brushed on.

There’s not a lot you can do to recover from the “frosty.” Sometimes a heavy re-coat over the frosty areas will consolidate the pigments and coat them into translucency, but that’s kind of iffy. You can also try coating with a gloss and then reapplying the clear flat. Success is not guaranteed. Still, it doesn’t hurt to try first. Neither of these methods will usually make things any worse.

Stripping and repainting is often the only surefire course of action. Sometimes it’s better to just hide with more weathering (as much as I hate to offer that as a possible solution).

4

I’ve never used it “neat”, I’ve only ever added it in small quantities to their matt varnish to make absoloutely sure I get a flat finish.

5

Thanks for that. Ive glossed the frosting with Future. Next try will be with Tamiya’s XF86 or Revell Aqua Color.

1 Like
6

@Denimo FWIW, I’d suggest Tamiya’s proprietary X-20A thinner (or their “yellow cap” lacquer thinner) for use with the XF-86 clear flat.

Reduce (i.e. thin) to what ever viscosity you normally use for Tamiya. Tamiya recommends about 2 parts paint + 1 part thinner. However, just about everybody I know (including myself) has their own preferred reducing ratio for Tamiya for airbrushing. If you’ve already got something that works for you, then probably best to stick with that. If you don’t normally use Tamiya, then do a couple of test spray outs to dial in you thinning ratio, air pressure and paint flow / application rate.

A couple of light coats with time to dry in between is usually better that a single heavy coat. Avoid using too high air pressure as that encourages orange peel and over-spray around corners and such (which will create the exact same kind of frosty white issue you just had - but caused by something different this time!).

Good luck!

7

Thanks for the great advice. I’ll use the Tamiya thinned. Im just putting the cargo retaining posts and the front cargo shelf on the Chapparal. Then its matt finish time!

Thanks Again.

1 Like
8

I use the Tamiya Clear Flat out of the spray can. Goes on thin, has a good flat finish, no mess, no fuss.
Ken.

9

Also make sure the humidity level of your application area is between 35 and 65 %…if you can measure it. Too high humidity will certainly “cloud” your work…having learned the hard way myself. Below 35%, static electricity can affect the spray pattern.