Making A Commercial Clear 06 Glaze White And Opaque?

[stonefly]

Hi Ceramicists!

 

I'm an elementary art teacher and have typically used colored commercial underglazes and a clear commercial overglaze for my little students to finish their work. (06, typical white low fire body) Recently I tried a version of

 in which the student work is first dipped in an opaque white glaze and commercial gloss colors are applied over.  It's a definite improvement in what I've been doing, and the kid's work came out much brighter and more appealing, the whole process was much more forgiving.  

 

Only this - I have three gallons of clear to use up.  Can I add zircopax or tin oxide or something else to my commercial clear to get a good white majolica base?

 

Thanks for any thoughts!

 

Cristy in WY

[Min]

Couple things come to mind, the commercial white you are using that works, do you know if it contains tin, zircopax or a combination of the two? If you can’t find that out I would test with zircopax first. 

 

I would weigh out 200 grams of the liquid clear glaze and then add 10 zircopax to that, dip a test piece and paint on some of your overglaze colours. Now add another 2 grams of zircopax and repeat process. I would then add another 2 grams and do a third test tile. You now have approx 10% zircopax on the first tile, 12 on the second, 14 on the third. If one of these is successful you can extrapolate the figures upwards for larger amounts. (I’m basing the figures on the liquid commercial glaze being approx 50% water)