Ceramic Human

We have anyone mixing glaze wear a mask with particle cartridges and mix outside. I was hoping that in addition to that we might vent it outside to keep the studio air clean.

I guess I said it all in the title. Our company currently mixes dry glazes out in the alley next to our building. It would be nice to be able to mix indoors but we'd need proper ventilation. We'd be saving lots of time mixing if we could do it right next to the sink. I was wondering if anyone has had or seen a set up with indoor ventilation like this before. Thoughts?

Makes sense. Looks like we have to drill 3/4" holes in order to use the protective case. That's what the bailey kiln person told me on the phone. Looks like I have an exciting afternoon of MANUAL READING ahead of me! To learn about the joys of "offsetting your bailey electric kiln." But hey, totally worth it if we can add 50 firings to the lifespan of a thermocouple and prevent defects in the process.

Looks like you guys covered this topic 4 years ago. I think I just need to do more browsing before I ask. Lots of good stuff here.

Yes. They are quite thin in some parts and have minor cracking. Seems like we may need to increase routine maintenance until we can get those covers put on.

Sorry. I'm reading about offsets now and what you said makes more sense.

So if we fire to 2167, we'd change the firing to 2185 ish? And all of the target temps by +15-20?

The kiln shelves sometimes get flakes but it is more rare, because most of the surface of the shelf is covered by mugs. looks to be on top of the glaze. I did go through with pliers and clean the ends of the thermocouples and they were VERY flaky, so I'm pursuing that as the most likely culprit. Potentially adding in routine thermocouple maintenance, or purchasing caps to slide over the thermocouples.

They go into the glaze firing clean and come out like this. Not on a massive scale, maybe one or two/day.

Wanted to ask you guys about your experience with this defect we've been having. It's not glaze specific and I highly doubt these growths are just bubbling up from the clay during a glaze firing (but maybe). This defect does not occur only on mugs that are close to the thermocouple, but I don't want to rule out the possibility that it is thermocouple related. Ring any bells?

Yeah, I thought about that and it's definitely possible, but I thought I'd ask you guys just to see if it was easy to rule out. There are so many factors, but I'm grateful to have this forum as a resource to help me get acquainted with the process. Sometimes it makes my head spin. I don't want to be an out of touch manager. The more information the better.

I'll crack open the next few that come out. Thanks.

I should have supplied more information. I didn't really give you guys a lot to go on. My bad. I'll look into the tools and possible contamination. A rate of 5/500 is 1% defect rate. I thought if it were a really simple fix then it would be worth reducing defect rates by 1%. Heck, even if it's not a simple fix. You fix two or three problems like this, and reduce your defect rate by half or more. I figure that's worth the time.

This particular glaze is the eggshell from Coyote. We mix a 25lb bags at a time and then sieve using 100 mesh. Not sure on the recipe for the dry mix, but I've attached a photo of the suggested water amount and specific gravity of eggshell. We only sieve after the initial mix. How frequently SHOULD a glaze be sieved?

We're firing in an electric kiln to cone5. Been getting green spots like this on several mugs/week. It's usually only 3-4 out of 500 but that starts to add up over years of business. Do you guys have any experience with this defect?