Pairing clay and glaze

[mkelly2]

New-ish potter here! I've taken many community classes before but am just starting a home studio (got wheel and kiln 2nd hand). Starting to gather materials now and am wondering if you have to match brand of clay with brand of glaze? I assume you don't have to? For example, I have ordered some Laguna WC-608 stoneware clay but have come across some Amaco brand glazes that I really like the look of. How do I tell if these two products will fit well together?

 

Thank you in advance, I'm sure I'll have lots more questions in the near future!

[Hulk]

Hi MKelly!

The matching likely to come down to "glaze fit" - where the glaze doesn't craze (crackles), nor shiver (flake off) due to mismatched expansion*. There could/may be other issues**, however, glaze fit is big.

In my (limited) experience, glaze and clay by same vendor does not guarantee a fit!

With a bit of luck, you might find someone who uses the clay you selected, that can recommend commercial glazes (or recipes).

If you liked the clay and glazes at the community ceramic lab, you could start with those products. I did not like the clay where I got my start, so started a new road there; as for glazes, the instructor copied recipes for me - I use one of them, the red! I've had some good luck with glaze recipes, however, well-behaved clear glaze has been an odyssey...

You will find out by testing! Glaze your test wares, then subject them to some stress to see if the glaze holds up.

May I suggest you take notes - hard to remember details down the road, e.g. thickness, times, temperatures, how close the crazing (hopefully, none),etc. - to refer to later on...

It might take a while to find clay and glaze combinations that work! From there, you might continue to explore and experiment, forever; on t'other hand, you might stick with a few proven combos...

 

*more reading on coe (coefficient of expansion)

Co-efficient of Thermal Expansion (digitalfire.com)

**Other issues could include how well the glaze sticks, and other application features, bubbling/fizzing, interaction with other glazes, how fluid it is (at peak temp), durability, stability, and more! What makes a good glaze?  Ah, indeed.

 

[LeeU]

I primarily use mid-fire commercial clay bodies & glazes from mainstream manufacturers such as  Amoco/Coyote/Laguna/Highwater/Sheffield/Standard etc. and have not had any problems whatsoever with clay-glaze fit.  I mix it all up and 99% of the time love the result. If you jot down what you used/what you did, if you run into issues you'll have a head start on figuring out what went wrong. Or what to do to duplicate that happy accident!

On 6/18/2021 at 9:13 PM, mkelly2 said:

match brand of clay with brand of glaze

Update--I should add that to some degree I just luck out, re: common commercial bodies/glazes & good fit & lack of (so far) other issues.  It is important to know the chemistry in the first place, even if one chooses to take the easier, softer way of pre-made materials. A lot of community classes are woefully lacking in teaching ceramic science and just steer newbies & hobby potters to commercial products & very simple group electric firings, without providing a sound foundation for working in clay. Education is everything!

[neilestrick]

Brand means nothing. It's all about glaze fit and COE as Hulk described. With commercial glazes there's not much you can do besides buy some and test them to see if they fit on your clay body. And just because one glaze in a glaze series fits, that doesn't mean that the others will. For instance, Amaco Potter's Choice glazes or Laguna's MS series are all different formulas, not just color variations of the same glaze. If you mix your own glazes then you can tweak glazes to fit.