Calcium borate frit subsitute

[Gonepotty]

Hi all, 

I have a Linda Bloomfield glaze book which with a shiny base recipe which calls for calcium borate frit.....this in no longer available in the UK. Wonder if you have any ideas of a substitution?

thanks!

 

[Magnolia Mud Research]

40 minutes ago, Gonepotty said:

I have a Linda Bloomfield glaze book which with a shiny base recipe which calls for calcium borate frit.....this in no longer available in the UK. Wonder if you have any ideas of a substitution?

https://glazy.org/materials/15096 

LT

[Callie Beller Diesel]

They have a number of different calcium borate frits on the market. I know Ferro has had production issues in the last year and they’re still sorting some things out, but there should be a number of alternatives in the UK. Worst case scenario, you can use Ulexite or Colemanite, but I believe common practice is to calcine it first, or it’ll cause glaze spitting.

If you have any familiarity with glaze calculation software, you can use glazy.com to substitute in another frit and maintain the chemistry.

If you don’t have any familiarity, post the recipe here and let us know which alternative frits your supplier has available, and one of us here can do the reformulation for you.

[High Bridge Pottery]

I wonder what happened to the frit, that one was my favourite

[Gonepotty]

It was suggested I try low expansion frit or borax frit 

[Min]

@Gonepotty, post the recipe and which frits you can get now. Also, can you get gerstley borate?

[Gonepotty]

Potash feldspar 34

Quartz 23

Calcium borate frit 14

China clay 13

Whiting 11

Dolomite 5

Can get Gillespie borate....

Edited February 6, 2022 by Gonepotty

[Min]

I reformulated your recipe using Gillespie Borate. Instead of using a hypothetical analysis for the China clay I used Grolleg for both the reformulated recipe and in the original. Let me know if you use a different kaolin / china clay and I can redo it. I used the chem analysis from Glazy for the original recipe using Calcium Borate frit from the link @Magnolia Mud Research provided above.  This looks okay on paper but if you try it please make sure and do a small test batch before using it on actual pots.

Linda Bloomfield ^6 Clear with Gillespie Borate - untested  No dolomite needed, its getting enough magnesium from the Gillespie.

Potash Feldspar 22.2

Silica 24.4

Gillespie Borate 27.1

Grolleg Kaolin 18.2

Whiting 8.1

total 100

 

 

 

 

[Gonepotty]

On 2/6/2022 at 11:24 PM, Min said:

I reformulated your recipe using Gillespie Borate. Instead of using a hypothetical analysis for the China clay I used Grolleg for both the reformulated recipe and in the original. Let me know if you use a different kaolin / china clay and I can redo it. I used the chem analysis from Glazy for the original recipe using Calcium Borate frit from the link @Magnolia Mud Research provided above.  This looks okay on paper but if you try it please make sure and do a small test batch before using it on actual pots.

Linda Bloomfield ^6 Clear with Gillespie Borate - untested  No dolomite needed, its getting enough magnesium from the Gillespie.

Potash Feldspar 22.2

Silica 24.4

Gillespie Borate 27.1

Grolleg Kaolin 18.2

Whiting 8.1

total 100

Screen shots of both the original and my version of it using Gillespie if you want to compare the chemistry.

 

thanks so much for your help. This is fantastic! I will test this out. Any pointers/youtube videos on how I could go about reformulating glazes as you have very kindly done? Im very new to creating glazes and this would be very useful.

[Callie Beller Diesel]

I have just the link you’re looking for!

https://help.glazy.org/guide/calculator/#automatically-importing-recipes

If you scroll down the menu on the left to the Calculator, the drop down under that has an example on how to substitute local materials into a glaze recipe and adjust the formulation so it matches.

It’s fantastic that potters from all over the world can share recipes, but we don’t have access to the exact same materials everywhere.

[Gonepotty]

Thank you so much for your help. I'm right at the very starting on mixing up glazes from scratch so have been thrown into the deep end of glaze chemistry which I am loving but equally lots to learn. Glazy.org has been amazing with recipes and community of potters all helping each other:)

[Min]

9 hours ago, Gonepotty said:

I'm right at the very starting on mixing up glazes from scratch so have been thrown into the deep end of glaze chemistry which I am loving but equally lots to learn.

Just for fun try alter the G2926B recipe you mentioned in your other thread by replacing the Ferro 3134 frit with your Gillespie Borate and see how close to the original formula you can get by increasing or decreasing amounts. I'ld start with balancing the boron then fluxes then the alumina then silica.  It will probably take going back and forth a bit bumping amounts up and down. When the formula is as close as you can get it then retotal the altered recipe to 100. If you aren't sure what each material contributes to the glaze just click on it from the page you linked and it will tell you what it's comprised of. You might not get it an exact formula match but you should get pretty close.

Using glaze chem software or not, if you do some reading on what the materials that are used in glazes contribute to the glaze is going to be very helpful. Otherwise it's a bit like diving into the deep end to try and use software without knowing what to alter to increase or decrease a quality of the glaze.  Example would be in the above glaze where is the calcium coming from? Main source of sodium and potassium? And so forth.

I'ld also strongly suggest just mixing up small test amounts of glazes before full buckets.  

[Clean Pottery]

Hi, I have a similar problem with the calcium borate frit for one very similar glaze from the same book. I am trying to figure out how to substitute using glaze.org but really I am a beginner and don't fully understand yet.

The recipe is as follows, and is the base glaze for Linda's runny transparent glaze that she adds various oxides to for different colour effects.

Soda feldspar 47

Calcium Borate frit 16

Whiting 14

China clay 5

Quartz 18

I don't suppose there would be anyone to help me make the substitution with the frit, for any of Ferro frit 3124, ferro frit 3134, or Gillespie Borate. I can get all of these.  

Thank you in advance 

[Callie Beller Diesel]

@Clean Pottery if you know the brand of feldspar you plan to use, that could help us get a lot closer. Estimated analyses tend to vary pretty widely from actual on feldspars in particular, and the ratios of alumina and silica are important on this particular conversion.

[Min]

Hi @Clean Pottery and welcome to the forum!

Is this the recipe (or close to it) that you are using? I've noticed that in the UK it is common to not give a specific brand or make to materials but rather go by descriptions as in your recipe. I went ahead and redid the recipe using a hypothetical analysis for the soda spar and used BPS Calcium Borate frit. Try plunking the recipe into Glazy and see if you get a similar formula and recipe. If you have a different frit use that instead of the BPS Calcium Borate frit I used. This should get you in the ballpark.

One thing to note, given the modified recipe has a much higher percentage of frit in the recipe than the original I would expect this version to be more fluid /runny. If this is a problem then increase the amount of china clay / grolleg plus silica in the recipe to counter this. If you need to do this try increasing in  small increments until it is dialled in. To keep the gloss level the same for every 1 gram of china clay you would also add 1.25 grams of silica. If this is necessary try 2 china clay + 2.5 silica then double then triple the amounts until it is as fluid/stiff as you are looking for.

Like all untested recipes only mix and test a small batch of glaze to thoroughly test before mixing up a large batch. (just round off the figures to the nearest tenth for a small batch)

Altered L.Bloomfield Alkaline Runny ^6

Soda feldspar 17.249 / Ferro Frit 3134 35.075 /  Whiting 9.614 / China Clay 19.303 / Silica 18.759 / total 100

Edited May 24, 2023 by Min

[Clean Pottery]

On 5/19/2023 at 1:25 AM, Min said:

Thank you for both the above suggestions. I feel like my head is spinning a little with trying to learn all this science - A little bit at at time I keep telling myself! I am only at the testing stage with this recipe, so was trying to find a simple solution to not being able to get the calcium borate frit. In the mean time however, I got in touch with Linda and she suggested switching the calcium borate frit with Standard Borax frit. It will make a very similar glaze, perhaps a little less runny, which for me isn't such a bad thing. I will try this to start with. Thank you for help, and here's to my ongoing learning of chemistry! 

 

[Min]

@Clean Pottery, glad you are open to getting another frit and trying that. I'm going to go ahead and delete my screenshot above but I'll write out the recipe just in case someone else reads this thread and is looking to sub the BPS Calcium Borate Frit. (I'm running out of storage space here for my images)