liambesaw

Not yet! The problem with using a focused beam is that clay 1) shrinks quite a lot when fired and 2) has a really bad time with temperature gradients.

When it thawed the water from the ice caused it to collapse

It fell apart when it thawed, I was thinking the same thing!

Oh sure, I agree with .3:.7, I'm just saying that paper made no sense, because even at .3:.7 there was significant leaching above 3% copper. I'd just say restricted compared to what? And how do they know? The evidence is missing from the paper.

Yeah but if it says the ratio made the glazes durable with no leaching, but then a few paragraphs later talked about how they leached quite a lot. So that throws the entire premise out the window in my book. I do believe that the most durable glazes keep within that range, but obviously copper had a very large affect on the durability, so their premise that copper would not affect durability is false.

That was my issue with the paper, it contradicts itself quite a few times in the durability section.

Sure! Freezing damage is VERY obvious

Cake decorating ribs have this profile

Yep, and really bad for pvc as well. My tap water from the city is generally extremely soft, 20ppm tds, and I've asked the city about it, but it's river water in the northwest and they are averse to adding minerals. So far so good though, and I have no copper piping in my house, but I know the mains are all probably steel. It'll catch up with them some day.

I do the same. My bisque chucks sit on a shelf because they're kind of a pain, the leather hard ones are best

Well there's also a pretty big difference between metallic copper pipe alloys carrying buffered water and copper oxides and carbonates in glaze. And if your water isn't buffered, well, look at some of the places in the country having some awful problems with lead in the water right now. Acidic tap water is real bad for pipes and solder.

Well they say their test yielded zero copper release but then post that almost 1 gram per liter leached into the acid with their matte glaze at 5% copper cone 6, and only 173 milligrams with 3% copper. I'd say that's quite a bit of durability loss at 5%. But the also say that their matte glaze also was more durable than their glossy, so I am not really computing what they're trying to say, other than copper is safe in glazes because it's not really that toxic.

The issue isn't with the copper itself, it's with the copper causing a softening of the otherwise durable glaze iirc. You could actually eat copper carbonate and live just fine (edit: don't eat copper carbonate)

I'd think tea would be acidic enough to pull copper from a glaze. Barium is a trickier beast that requires special chemistry and firing to be durable. I'd say no to a barium matte at cone 6 oxidation because from my research it is not possible to make this durable.

I just sent an order to the Netherlands, was only 12 mugs but they were quite large! 35lbs, $150 shipping. Shipped in multiple packages was much more expensive! I used heavy duty moving box (double layer corrugated) from home depot as the main box and wrapped each mug in clay box like Marc. Was enough room in the box for a 2 inch layer of peanuts all the way around. The mugs were all taped together in the center. Worked great.