Beginner's guide to using metal oxides and carbonates

[Claudia]

I am just learning all of this...I know I want to experiment with metal oxides and carbonates, but I don't want to buy a bunch of stuff I don't need. Can anyone recommend some good ones to start with, and a source for relatively small quantities of them?

[plodder]

Hi Claudia,
I suspect that you are resident in the US and as I'm in the UK I can't give you information on 'stateside' suppliers however, most suppliers of ceramic materials ( certainly in the UK) are set up to send small quantities of oxides( 100 grams +) via postal services and as these amounts are relatively inexpensive you could start by buying several oxides or carbonates. I would suggest that you start with:

Iron oxide (terracotta to rust reds);
Cobalt carbonate ( for a range of blues);
Copper carbonate (for a range of greens);
Manganese dioxide (for brownish purples);
Ochre, another form of iron oxide (for earthy ochre yellows).

If you intend to use these colorants on their own you might want to include Copper oxide which in fairly high concentration will give charcoal black. To use without a glaze simply mix with water and use in varying concentrations; they settle quickly so stir occasionally while using.

If you intend to use them in conjunction with glazes I would suggest you start with a simple transparent glaze and add very small percentages (0.5 of a gram to 5 grams per 100 grams of dry glaze ); try this also with a simple white glaze.

Once you have tried them out singularly, you could then begin to try different combinations, BUT have a care as oxides also have strong fluxing properties and this can increase exponentially causing glazes to run ( quite badly sometimes, particularly copper oxide).

If you could post again with a little more information regarding how you intend to begin using oxides (Firing temperatures, kiln atmosphere (oxidised or reduction etc.), glazes) it would be easier to advise you.

'Hope this is of some use, Plodder (Andy)

[Claudia]

Thanks Andy, I appreciate that information. I am in fact stateside, and I just ordered some red iron oxide which I will begin experimenting with. Next order I will get some of the others you suggested.

I am just learning all this stuff, and want to experiment with all sorts of things, not just oxides. Thanks for giving me the basic starter list.

I will be doing cone 06 and cone 5 firings for now, in an electric kiln. Any useful info regarding those temps is much appreciated as well.