Glass paint: Any use in modelling?

[Evil Eye]

So at a small craft shop today I acquired some rather imteresting stuff- Marabu GlasArt glass paint. I'd used it a long, long, LONG time ago when I didn't know anything about paint (and predictably made a complete mess with it) but I thought it would be worth giving it a second try now I know what I'm doing a bit better.

 

The pot says it takes 3 days to cure properly, which sounds about right. And from what I can tell, it seems to be alcohol-based. It's also very runny, so presumably it won't require much in the way of thinning (if any at all). The problem is, I have no idea if it's even suitable for use on anything other than glass. I can't think why it wouldn't work, but then I'm not a chemist. I want to test it out though my airbrush, but the cold weather means I can't until I either establish an indoor airbrushing station or the weather gets better.

 

My greatest fear is that because it's not very viscous at all, it might just run straight off the model. I have no idea if it would do this, but it would be good to know how to avoid that happening (with any overly thin/runny paint for that matter).

 

So a few questions really.

1: Can it be airbrushed?

2: What exactly IS it? Is it an acrylic or a lacquer? Or something else altogether? How should it be treated?

3: Does it have any application for modelling?

 

Thanks!

[Marshal van Trapp]

Sounds like it would be good for tinting clear plastic pieces like the canopy on eldar vehicles

[Arkhanist]

According to the safety data sheet, it's an alkyd resin based paint, with a organic solvents. It's pretty similar to an oil paint, but more fluid and translucent, and dries a bit harder and faster than a conventional oil paint - but definitely slower than acrylics. Suitable for use on glass, porcelain and acrylic plastic - 40k models will take oils just fine, so should be ok and shouldn't melt the model! A proper primer coat first will help with adhesion to the model.

 

Mineral spirits would work for thinning for brush application, but would likely take too long to dry when spraying - the recommendation here, if needed, is xylene or naptha (it already contains the latter). Even so, you'd have to go very thin coats to avoid spidering or runs, and wait a while between them - it won't dry as quickly on contact with the surface like an airbrushed acrylic will. Acetone will dry it much quicker according to that latter link, so that might actually make it easier to spray for our scale?

 

Oil paints with organic solvents can apparently be airbrushed with the following caveats:

 

1) organic solvents can be a bit corrosive to airbrush seals if they're not PTFE, though not as bad as lacquer thinners.

2) Organic solvents are not good stuff to breath, particularly when spraying, so you'd definitely want to spray in a well ventilated area you can let air out after - or outside - and use a respirator rated for solvents and gloves. Wouldn't recommend in your living room.

3) higher PSI - 30 or more.

4) You'd also need to put neat thinner through the brush after to clean it, so dispose of with care.

5) don't spray on naked flame, or drink it, obviously.

 

Does sound like it could do an interesting translucent glossy effect over a metallic base coat, similar to tamiya transparents. Or an alternative to the citadel gem-effect paints over silver with a brush, which might be the easiest way to use it!

 

Hmm - my wife has some glass paints stashed away somewhere, I might try out that last one myself...

Edited January 11, 2018 by Arkhanist

[Arkhanist]

 

My greatest fear is that because it's not very viscous at all, it might just run straight off the model. I have no idea if it would do this, but it would be good to know how to avoid that happening (with any overly thin/runny paint for that matter).

 

On this point, I have personal experience with acrylics :) Artist's matt medium is usually more viscous than our paint, so works quite well to thicken up paint that's been thinned too far for brush control, and the medium itself helps with adhesion&drying if you've been thinning with water. You can get away with a lot with an airbrush though; people do inks all the time which are pretty close to water at our scale. Drop the PSI, go easy on the trigger to do thin layers, and get closer to the model if it's drying midair. That sweet spot between viscosity, PSI and the coverage zone you want to get proper layers varies tremendously by paint, and finding it takes a lot of practise.

[Evil Eye]

Thanks!

 

This particular brand seems to be VERY thin, so maybe thinning it won't be an issue after all. In any event, for cleaning my airbrush (if I decide to use them) I'll probably invest in some naptha. Assuming I can find it anyway.

 

Of course this seems to be a fairly academic question anyway, as I have discovered that mixing plain old artist's ink (in this case purple) with Tamiya's clear medium makes for a superb clear paint- pretty much identical in behaviour to Tamiya's premixed clear paints in fact. At last, a solution to the "Tamiya doesn't do a clear purple" problem that doesn't involve me having to import Mr Hobby's awesome but expensive paints!