Stock Solutions For Glaze Testing

[tb001]

I know I've seen several strategies for glaze testing using line blends, but do people use stock solutions in ceramics? As a former scientist, I used to use 10x stock solutions to make up a buffer, etc... all the time. Seems like this is an obvious way to easily test many different glazes, but haven't seen this referenced.

 

Is there a reason people don't do this? I would imagine some of the colorants would need to be prepped in alcohol?

[tb001]

Crud, think there's a duplicate post. Not sure what happened. Hopefully a mod can delete.

[Guest JBaymore]

Done.

[neilestrick]

I know I've seen several strategies for glaze testing using line blends, but do people use stock solutions in ceramics? As a former scientist, I used to use 10x stock solutions to make up a buffer, etc... all the time. Seems like this is an obvious way to easily test many different glazes, but haven't seen this referenced.

 

Is there a reason people don't do this? I would imagine some of the colorants would need to be prepped in alcohol?

 

As a former preschool teacher, I have no idea what this means.

[tb001]

Ha! I just mean using super concentrated solutions of the individual ingredients for a glaze. So if you want to make a glaze with 1% colorant, you make a solution with 10% colorant and use 1/10th of this solution. We did this in the lab all the time--just means you can combine the stock solutions to make a final result much faster. It also means less error because means you don't weigh out very small quantities for a 100ml glaze test.

 

It seems like the same principle *should* apply, but surprised no one does it, so I figure there must be a reason!

[neilestrick]

Ha! I just mean using super concentrated solutions of the individual ingredients for a glaze. So if you want to make a glaze with 1% colorant, you make a solution with 10% colorant and use 1/10th of this solution. We did this in the lab all the time--just means you can combine the stock solutions to make a final result much faster. It also means less error because means you don't weigh out very small quantities for a 100ml glaze test.

 

It seems like the same principle *should* apply, but surprised no one does it, so I figure there must be a reason!

 

Thank you for the explanation. The problem is that most glaze colorants, being metallic oxides, don't stay suspended very well at all. You could, I suppose, mix them up in a gum solution, but that just adds more steps and probably negates the benefits.

 

When doing line blends, you can do them as liquid volume measurements rather than weighing out each little portion. You just have to mix each end of the blend to the same volume and go from there. I think that would be similar to what you're describing.

[Marko]

I haven't a clue, but I do Google. nuk nuk nuk. Here's a link right here on CAD: http://ceramicartsdaily.org/ceramic-glaze-recipes/glaze-chemistry-ceramic-glaze-recipes-2/line-blends-a-surefire-way-to-build-your-understanding-of-ceramic-glaze-materials/

[tb001]

Yes, definitely similar to a line blend, but should give you more flexibility in mixing the different components. So you could easily make a test glaze with x% colorant, y% neph sye, z% rutile by adding a small bit of each concentrated solution to a base glaze.

 

I'm guessing the issue is one of solubility, as you mentioned, and perhaps stability. We had certain tricks we used to get things into solution (heat, alcohol or oil instead of water, ph, to name a few). Wonder if this might work or would end up being problematic in the final glaze.

 

Unfortunately, my studio is mid remodel and life is getting in the way of finishing it, so in the interim, I dream of glaze combinations! When I finally get up and running have so many things to test!!

[Marko]

Yes, definitely similar to a line blend, but should give you more flexibility in mixing the different components. So you could easily make a test glaze with x% colorant, y% neph sye, z% rutile by adding a small bit of each concentrated solution to a base glaze.

 

I'm guessing the issue is one of solubility, as you mentioned, and perhaps stability. We had certain tricks we used to get things into solution (heat, alcohol or oil instead of water, ph, to name a few). Wonder if this might work or would end up being problematic in the final glaze.

 

Unfortunately, my studio is mid remodel and life is getting in the way of finishing it, so in the interim, I dream of glaze combinations! When I finally get up and running have so many things to test!!

Have fun.

[terrim8]

you might like this site   http://digitalfire.com/index.php

 

(2nd time I've recommended this- wonder if there's a referrer's reward?)

[oldlady]

tb001, my studio is in harpers ferry, wv.  if you are anywhere near, please come and make glazes.  i have everything you need,    i have no interest in testing glazes at all, be my guest.

[LinR]

Isn't the problem that glazes are suspensions and not solutions?  Lin

[oldlady]

we do have something similar, base glaze.  make up a bucket of EDIT DRY base glaze and then use various colorants in it.  you can test a tiny amount, 10 grams base will show whether or not a particular colorant works with that base or not.  that is about a tablespoonful. 

[neilestrick]

Isn't the problem that glazes are suspensions and not solutions?  Lin

 

Bingo. Trying to keep individual ingredients in suspension would be an issue.

[High Bridge Pottery]

One thing I do is make up a big batch of a base glaze I am testing to a known specific gravity so you have an estimate of grams per ml that is good enough for me.

 

Taken from http://www.potters.org/subject11877.htm

 

 

 

Because the density of dry matter in most non-lead glazes is about 2500 g/l 
and the density of water is about 1000 g/l, the formula simplifies to: 

g dry matter per liter of slop = (density of slop - 1000) 5/3 


So, for example, suppose that a liter of your glaze slop weighs 1500 g. 
Then the amount of dry material in it is (1500-1000)5/3 = 833.3 g dry matter 
per liter. And since the total slop mass is 1500 g, we also know that the 
glaze slop contains 1500-833.3 = 666.7 g water per liter of slop. 

For most purposes, this formula is accurate enough. For greater accuracy, 
you (or your glaze program) can calculate the actual density of your dry 
glaze and you can determine the actual density of your local water at your 
room temperature.

 

 

I use it to take my base glaze and start adding in stuff in small test batches but if you were clever you could probably suspend most things that only required a quick mix before drawing off the ml/g you need. In practise I am not sure how well it would work with all materials and is it worth only having half of them in a solution/glaze. It certainly works well for mixing up a big batch of glaze and taking 25ml and adding whatever % of stuff you like.

[tb001]

Ah, the suspension vs solution makes sense! I may try a version of what highbridge suggested. If I ever get back into the studio that is... An 8mo old baby and a full time (plus some) job sure is putting a dent in my studio time!