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Differences between various Thompson's products as medium

Posted: Sun Nov 09, 2003 2:22 pm
by Geri Comstock
Thanks to Bert, I got my first lesson on using an airbrush yesterday. So much fun!

I've been looking on the net for suppliers of Klyr Fire and noticed some other products on the Thompson's site: Agar and Holding Agent. I looked through the archives and old archives and couldn't find an answer to this question...

Will Agar work in an airbrush as a medium for micas? It says it's more viscous. If it's too thick, can it be watered down to the right consistency to use instead of Klyr Fire?

I also noticed the Holding Agent and read that some folks have been using this in place of Elmer's. Does this stuff work as a medium in an air brush or is it too thick? Can it be watered down?

Thanks for any insights...

Geri

Posted: Sun Nov 09, 2003 3:46 pm
by Bert Weiss
Geri

Thompson enamels are more like BE frit than finely ground enamels. I don't think that spraying coarser frits is practical, although I wouldn't be surprised if somebody has a technique for it.

Agar is a seaweed derived gelatin. It may work as a vehicle and binder and burn out cleanly. I never messed around with it.

The holding agent is designed to hold on to frit that has been sifted on to the glass. I have heard of people using aloe vera gel for that purpose, as well as Klyr fire. Elmers is a bit thick and sounds overkilly to me.

I bet there is a binder that can be mixed with isopropyl alcohol to do a fast drying spray with mica or enamel. possiblly a very small amount of shellac. or maybe waterglass. If the waterglass (sodium silicate) dries in your airbrush it could kill it though.

Ferro has a spray medium that you mix a little bit in with distilled water. They sent me a sample, but forgot to put it in a plastic lined can and the can corroded and turned the medium in to a substance that looks like blackstrap molasses. Come to think of it this might be just fine for spraying black enamel. A little extra iron oxide could be a good thing I suppose.

Re: Differences between various Thompson's products as mediu

Posted: Sun Nov 09, 2003 5:43 pm
by Don Burt
I should try that agar. It says its water-based and is a solution, so certainly it can be thinned with water.

I've never sprayed mica either.

But I have sprayed glass paint with Klyr Fire and Thompsons A13 acrylic. I've added Golden airbrush acrylic medium, for thinning acrylics, and have used a couple other commercial wetting and airbrush medium extenders. The Thompsons A13 has some promise for glass painting, but I haven't learned to control it yet. Lately I'm back to just adding a couple drops of liquitex airbrush extender into my water/gum arabic mix.

My only complaint about Klyr Fire w/water is that the airbrush makes it bubble out of the reservoir.

Posted: Sun Nov 09, 2003 9:32 pm
by The Hobbyist
My preference for airbrushing enamels is Ferro #683. It is a gyycol ether and cellulose ether with alcohol. It mixes to a smooth consistancy which I thin with alcohol for spraying.

I like spraying with alcohol based because it dries so quickly but doesn't plug up the gun. Easy cleaning too.

I've tried gum arabic but it must be mixed with water so it dries too slowly here in the swamps. It is also harder to clean because when it dries it really sticks. If you can deal with water based you might try gum arabic.

The Hobbyist......................Jim

ps. Klyr-fire and alcohol or a drop of soap with water seem to both work with mica. I'll bet you could dip in mica water. hahaha

Posted: Mon Nov 10, 2003 7:43 am
by rosanna gusler
i like thompsons a-13 enamel medium. if it is too fast drying, use a little glycerin in the mix. if it is too slow, thin with grain alcolhol. denatured does weird stuff occasionally. rosanna