Hey everyone! We've been addressing questions about the bloating issues with the new clay body in the Watertown discussion forum, but I figured I would post them here in the general discussion forum in case anyone missed it. Here is Ned's response:

It's something we've been seeing since we starting using the 710 clay. There's been a consistent rate of bloating that frankly would have already deterred us from keeping the clay. There has been so much excitement at both studios though over the colors and textures this clay produces that we've stuck with it, and even invested the time and energy to create a glaze board in Belmont.

Bloating in clay bodies can come and go if it's due to manufacturing impurities. In this case, the bloating is because of the high metal content in the clay which gives it the dark color.

I talked to Julie at Standard Clay. She is their tech rep. She offered the idea of bisquing at a higher temp or glazing at a lower temp (like some of your pottery forum responses suggest).

As a matter of principle, I almost never make system-wide changes in our firing cycles to accommodate a specific clay or glaze. The effects are cascading and it's not worth it. In this case, Jared and I will experiment with some adjustments. If we can make a change that's practical and doesn't throw off everything else, we will.

In the meantime, our message to students is that you should use the charcoal brown clay knowing the risk of bloating. If you're spending a lot of time on a single piece, it might not be worth it to use the clay. For context, we've used approximately 5,000lbs of 710 between both studios since February. I'd guesstimate that each piece has a 2-4% chance of bloating.

TLDR: We know about the bloating and are working on a solution. If we can't find one, we may get rid of it.