Using Darvan 7 or something else to reconstitute old commercial glazes

[Karen Singer]

Hi, I am a ceramic tile maker and I use a lot of commercial glazes in my work. I have been doing this for over 30 years and have found that I can almost always bring glazes back to a usable consistency by breaking up the pieces, adding water and mixing.

I am having a lot of trouble doing this with matte glazes in particular. We are finding that they tend to lift off the bisqued tiles. I have seen a lot of posts about using Amaco's gum solution. I have done this with mixed results. Recently, Darvan 7 was recommended.

I recently started using an immersion blender to do this, which seems to help, but it is a continuous challenge. Any suggestions or advice will be greatly appreciated.

[Pres]

Reconstituting bottled glazes was always a pain for me when teaching at the HS. Having to get the dried material out of the bottoms of the containers was pretty tough with the narrow neck of some jars. I often would have students clean out jars that I had used up, and save them. Then I would work on the dried out glazes. . . cut off the bottle just above the material inside, split down the side to the bottom and peal back the edges. Usually just doing this will pop out the dried glaze if that dry. If still wet cutting of the top makes the job easier to remove the caked material in the bottom once the wet stuff is drained. Back then I would use a ricer to mash up the old glaze, later would use the stick blender when I got one. I used to use gum arabic to add some body to the glaze, I also used some Epsom salts to the glaze from a container of saturated Epsom salts water. 1/2 to full teaspoon per pint,  These methods were used in the early years of my teaching around 73- 76. I took over the ceramics classes in  74, and made a quick transition to powdered glazes from other manufacturers than the previous teacher used, as I was interested in moving the program to cone 6, and adding a wheel throwing component to the program.

Hope you find some answers here, and a Hearty WELCOME to the forum! Best of luck to your continued work with the tiles.

 

best,

Pres

[Karen Singer]

Pres,

Thank you so much for your detailed reply! I will explore the Epsom Salts method. The ricer is also a good idea. We use forks a lot to mix in small containers. Does anyone have an idea why this seems to be worse with matte glazes?

Thanks for the Welcome to the Forum. I really appreciate it!

 

[Callie Beller Diesel]

Some of the mineral glaze ingredients are more prone to hard panning than others, and might need more gum or other suspenders to make them brushable. Those gums are going to help create that rock in the bottom of the bottle when they dry out. Because we’re talking about a commercial glaze that we don’t have the recipe for, which one of the many possibilities it could be would be a guess on our part.  It depends on which mechanism the glaze is using to become a matte.

[Karen Singer]

Hi, Callie. Thank you for responding. I am wondering about calling Amaco's support line to see if they can help. Has anyone tried this?

[Min]

If it's an old brush on glaze, from Amaco:

[mr_glazy_man]

We have this issue. We solved it by get a high shear dispersion blade and a mixer that  we can manually set the position (height) on. We’d fill the bucket with water, position the mixer blade at the top of the glaze and progressively lower it as the blade cuts through the glaze. The Epsom Salt solution helps greatly in flocculating the glaze and aid mixing. You’ll then need to wait a day once it has mixed so that you can skim off the water and get the right Specific Gravity,