Since KPS has been in constant business with the same owners since 1974, you can always be sure of a continuing supply of this high quality, very low soluble borate frit.
Test it first as a one-to-one substitution. Weigh Murrays Borate out just as if it were Gerstley Borate. Add Bentonite if needed (read below).
Do I Still Have To Add Bentonite? I thought it was a one-to-one substitution.
We have revised the Murrays Borate "B" formula to contain a 6% bentonite addition. Some glazes might need a maximum of up to 10% bentonite to your glaze. Please test on a regular "throw-away" pot before mixing large amounts. Some of the natural properties of Gerstley Borate were to act as a glaze suspender and binder. Although Murrays Borate will not settle into a hard mass at he bottom of your bucket like a straight frit would, it does it does require this addition of bentonite to keep it stuck to the clay surface. If you have any doubt, add 4% additional bentonite, it will not change your basic glaze. This addition of 6% bentonite should maintain glaze stability, but we highly recommend testing each particular glaze on each clay used.
IMPORTANT: Bentonite addition is a very important factor in using this frit successfully. It may be necessary to add even more Bentonite to some glazes with no clay or little clay content. Up to 10% addition will be useful as Gerstley Borate had between 5-8% Bentonite-type clay as part of its natural make-up. As an example: Murrays Borate 80%, Nepheline Syenite 20%, Bentonite 4%. Some glazes might even need a small amount of gum, like CMC or V-Gum-T.
Why Doesn't Kickwheel Add The Bentonite For Us?
After several years of customer feed back, this product works very well in raku glazes. It will perform well in many cone 6 glazes, but has difficulty at cone 10.
Is Murrays Borate Food Safe?
Yes, as an individual product, it is completely food safe and non- toxic.
Why Is A Frit Better Than A Natural Substance Like Gerstley Borate Was, Or Even A Blended Substance?
What Kind Of Problems Have People Had?
People are experiencing very little color change. Having the glaze not bind to the pot is the most common complaint and is why we now add the 6% bentonite for you.
We do not believe that there is only one "Magic Bullet" that will cure every glaze problem. The problems encountered thus far have been: glaze not binding properly, glaze too matte or too runny. We can not stress enough that you will have to experiment. There are thousands of GB glazes in use by potters today. Minor adjustments might be necessary for some glazes. We offer free phone, e-mail, or in-showroom customer support for glaze adjustment when needed. High temp. glazes with high surface tension (generally very glossy) are more likely not to work with MB.
What If My Glaze Is Too Matte?
We suggest that you only make a change in the amount of Murrays Borate added. Since Murrays Borate is acting as a fluxing (melting) agent, we recommend that you slowly increase the Murrays Borate to the point that will match your previous GB results. Usually an increase of around 5% MB is all that is required.
What If My Glaze Is Too Fluid And Runs?
We suggest that you make a gradual decrease in the Murrays Borate content until you match your previous results. Usually a decrease of around 5% MB is all that is required. The idea is to make as few changes as possible to your basic formula. Other customers have also added an additional 5% of EPK to counter this effect by forcing a higher melt temp.
What If My Glaze Doesn't Want To Stick To The Pot Even If I Have Added The Recommended Amount Of Bentonite?
We ask that you try the addition of a stronger binder like CMC or V-Gum T.
I Understand Gerstley Borate Is Currently Available, And That You Also Sell GB. What Is My Long Term Solution?
Begin experimenting with glazes that were not formulated with Gerstley Borate. No commercial glaze company every used GB, which was one of the reasons US Borax closed the mine. The unusual and sometimes unpredictable results that we always loved, drove glaze large companies insane, and sometimes potters joined them. Try this, try other subs and try other base glazes.
NOTE:
Remember we recommend a test of all glazes before actual use. We have run extensive tests, but you also have the responsibility to run your own tests before actual use.
KPS wants the very best and easiest to use product possible. We are very interested in your feed-back on how you are using this Gerstley Borate substitute and the results you are getting. Your feedback will help us make a better product and be able to assist other potters.
Chemical Analysis for Murrays Borate
MSDS for Murrays Borate
Please fill out Murrays Borate Questionnaire
3/06