So, in my infinite wisdom I decided that I was going to use glass paint on some acrylic spheres for a costume. Two months and four re-dos later, I'm at my wit's end with the stuff! Here's the problems that I have, and the solutions I found, but I'm still not completely happy with the finish and would love to hear the tips and tricks other people have for working with this stuff.

1) It's sticky, therefore dust sticks to it like anything. There's nothing I can do about this (even putting an upside down container over it doesn't help) so I have to rely on multiple layers of PVA to even out the surface.

2) It ruins brushes, even when you wash the brush in white spirit. The brush stays soft but the bristles clump and you don't get a nice smooth coverage anymore. Byebye to using that brush for anything other than PVA in future! I've tried a few different recommendations from my local art store (Taklon etc) and none of them are suitable D: Short of forking out ubermonies for a badger hair brush, I'm at a loss!

3) It lifts itself off as you brush over areas you've already applied. The only way I found to apply it was to brush evenly in the same direction. Which is all well and good on a flat surface, but you can kinda guess what happens when trying to do this on a spherical object D:

4) Brush strokes are really obvious. I've tried using a bigger brush to help with this, because thinning down the paint just makes it dribble due to the curvature of the sphere

So those are my three main problems with it. Admittedly a lot of the problems seem to originate from the fact that I'm trying to paint a spherical object, but I'm this close to scrubbing the lot off for the fifth time and spending £40-odd on an airbrush, so please share your hints in the name of saving my sanity!

I would just spend the money on the airbrush, personally. You can use them for pretty much everything costume paint wise, and I believe they can take all kinds of paints too (don't hold me to that).

However, if you don't think you'd use it ever again, then maybe try spray paints?? You can spray on cars, windows, etc with them, so I imagine it'll be fine with what you want.

Which type of glass paint are you using? (More for curiosity sake) I found the decoarts one to work quite well, but then again I was using it on a flat surface. When your painting the spheres does the paint need to remain translucent or can it be opaque becuase I agree that Spray paint can be a good option. Another option could be coloured accetate glued to the sphere with PVA. Naturally this option would depend on the amount of detail you wish to add. Finally there are glass pens that you can get so you draw the design on. This might be worth a try as won't have the problem of ruining brushes

Another option might be to look out for christmas baubles in the sales and see if you can get them in the correct size/colour or leaving the spheres clear and filling them with desired coloured light from say a glow stick and shredded paper/foil in the correct color?

I'm using solvent based Marabu GlasArt. It needs to be transparent because I'm cosplaying this character:

http://www.cosplayisland.co.uk/costume/view/67436

So sadly opaque spray paints are not suitable. You can buy transparent spray paint for glass but sadly they don't do the colour - I'd have to do one layer of yellow and two layers of blue, which will affect the transparency and make it really dark, I would imagine. I have a plastic bauble I bought, but the seam is really obvious (it's the type that comes in two halves) so again, not the look I was going for! You can use Marabu GlasArt with an airbrush, the website gives instructions for airbrush pressure, nozzle width etc. It's just the cheapest one I can find is £80 (my fiance would go halves on it with me as he can use it for his models).

I have a passable coating on the crystal for my umpteenth attempt - I did the last time too, and then my art store sold me Plastikote varnish which isn't actually suitable for plastic, and it ruined it so I had to start all over again. Le sigh. It's just frustrating because I've had to buy three brushes (at £3-4 a pop) because the glass paint is so sticky to work with. Never want to work with it again! Haha, most folks have told me to just suck it up and buy an airbrush, but I hope anyone wanting to do something similar with glass paint is now warned against it XD

You could try using the Marabu Decoglas instead, it's the water based version of the solvent based GlasArt, solvent based paints will always cause havoc on your brushes unless you have proper brush cleaners

It's also more suitable for acrylic plastics than the solvent version and because it's water based and dries more quickly you can dilute with a little water and apply in thinner coats to help reduce streaks

Overall Decoglas is much more user friendly ^^

I did look at that - have you used it with a PVA topcoat at all? I didn't get it because I was worried about it reacting with the PVA and going all peculiar! I was cleaning my brushes with white spirit but the bristles still clump at the very ends

If I understand you correctly you are trying to give a coloured tint to clear, colourless acrylic spheres while still leaving them transparent. You also want the surface to be free of brush marks.

Okay, this is not a method I have tried yet but it is one I have come across while researching costumes and it may work for you. I have heard that you can use rit dye to colour plastics. A quick dip will colour the surface but leave it transparent. It should also leave the surface smooth. You can see a tutorial of someone using it to colour a helment visor here.

It might be worth looking at.

That looks interesting - seems like the guy managed okay with the curvature of the helmet without getting any drip marks or anything. If the dye impregnates the plastic then that'd work really well! I'll see how my latest painting attempt turns out with a PVA layer or two, and then if it doesn't work out then I'll give that a try, as a few packs of dye and a pot will be cheaper than buying an airbrush!!

Yeah that tutorial looks like a good idea! I will have to remember that one ^^

Not sure how Decoglas would react with PVA but I would have thought once the paints fully dry it would be fine to put over the top

Also I think Marabu do a brush cleaner specifically for the GlasArt range if you want to try and save your brushes (I deal with Marabu through work pretty sure it's in the catalogue) I'm guessing it's a known problem ^^

Yeah, my art store said white spirit did the same thing, although as they gave me the dud advice about the Plastikote varnish maybe I would have been better off with the proper cleaner - although on the web there's many places that mention the cleaner and white spirit interchangeably. Tbh I found that the glass paint actually tinted the white spirit (even after changing it for a fresh pot a few times) and even after cleaning it for ages the brush was still tinted blue and had bits of blue coming off on the kitchen towel. Nightmare! I guess I wouldn't have had this problem if I'd gone for the water-based stuff. I was just really paranoid about it coming off somehow and ruining the rest of my costume. These things you learn!

That makes me very glad I didn't order any of the GlasArt! The Rit dye sounds like it might be the best option if the PVA doesn't work

Can't wait to see the finished cosplay, it looks epic!

And so I continue to be unsuccessful. Attempt #5 at the glass paint failed - top half went on beautifully, bottom half made a slight error, scrubbed it off with white spirit, but no, you can't just paint in the spot you left clear, because it causes the edge of your last layer to wrinkle and bubble, leaving a massive ridge.

They've changed the formula of Rit dye so it no longer works with plastics - not to mention that it never worked with acrylic anyway, apparently - the old formula was fine for polycarbonate plastics and the like, but if you have acrylic, forget it.

So today I bought some Adirondack alcohol ink - alcohol ink works for wigs, and this stuff claims to work with nonporous surfaces. Two coats of blue slathered on and rubbed around produces a very faint hint of lilac - the felt applicator one is supposed to use just ends up taking the paint off like when I tried this method with the glass paint.

I guess I'm buying an airbrush then

Are you able to open the spheres? If you could, you could maybe use spray paint inside it so you have the smoothness of the original sphere and the colour you want.

They're acrylic with no seam, so sadly not! But I bought them that way because my experiments with the Christmas bauble type ones show that the seam is really obvious especially when painted.

I tried diluting the glass paint with white spirit and putting it in a spray bottle, and spraying it on. It's actually looking pretty alright, my only fear is that a ridge will form where the sphere sits on the kitchen towel and leave an obvious line when I go to spray the underside, but it sure does look a lot better than when I was trying with a brush! Will have to see what it's like when it's dried.

That's really good to know actually as I've bought some plastic baubles and I'm going to be attempting exactly what you've tried here.

Here's a pic so you can see what happens if you use the seamed baubles that come in two halves:



Left is acrylic contact juggling ball sprayed with glass paint diluted with white spirit, middle is the bauble, right is the other contact juggling ball that was slathered with two layers of neat Adironack alcohol ink (denim blue). There's a pic of the transparent bauble on my costume journal as well. If you weren't using transparent paint then you could slather the seam with polyfilla or PVA to hide it before spraying - my main issue was that I was using transparent paint. Also if you're imbedding the bauble into something then if you do it so the seam is sideways then you can't really see it.

Hope that helps! I'm sticking with the diluted glass paint and spray bottle method - it's a little streaky but looks a lot better than the really obvious brush marks that occurred with my original method.

Thanks very much. That Dark blue one looks exactly like what I have. I've got 4 so might as well give it a try. It's going to be used as the ball itself so can't really hide anything but it's just a fun prop rather than a costume killer so I might just give it a go.

Those glass paints sound hard to use.
You can buy transparent blue model paints. Humbrol do transparent blue, these are enamel so will be tougher than acrylic. There are also acrylic versions of transparent blue eg Vallejo Model Colour. Acrylic paints tend to be softer than enamel paints so are more prone to scratching. But you could seal and protect the tinted clolour layer with some coats of clear gloss on top.
If the transparent colour is still too strong out of the bottle you can thin it down by mixing it with a clear gloss version of the same paint brand. Ive got a feeling that even with an airbrush it will not be easy to get a uniform colour though. Best I can suggest is spray from a distance not right close up, dont put too much thinners or it can run/drip - because you are spraying onto a non porous surface so it will take longer to evaporate and dry off, dont use too high air pressure or you could cause 'spidering' runs on the wet surface. At least thats how I would attempt this.