Jump to content
  • Announcements

    • Jennifer Harnetty

      Moderators needed!   12/08/2017

      Ceramic Arts Network is looking for two new forum moderators for the Clay and Glaze Chemistry and Equipment Use and Repair sections of the Ceramic Arts Network Community Forum. We are looking for somebody who is an active participant (i.e. somebody who participates on a daily basis, or near daily) on the forum. Moderators must be willing to monitor the forum on a daily basis to remove spam, make sure members are adhering to the Forum Terms of Use, and make sure posts are in the appropriate categories. In addition to moderating their primary sections, Moderators must work as a team with other moderators to monitor the areas of the forum that do not have dedicated moderators (Educational Approaches and Resources, Aesthetic Approaches and Philosophy, etc.). Moderators must have a solid understanding of the area of the forum they are going to moderate (i.e. the Clay and Glaze Chemistry moderator must be somebody who mixes, tests, and has a decent understanding of materials). Moderators must be diplomatic communicators, be receptive to others’ ideas, and be able to see things from multiple perspectives. This is a volunteer position that comes with an honorary annual ICAN Gold membership. If you are interested, please send an email outlining your experience and qualifications to jharnetty@ceramics.org.
Sign in to follow this  
Natania

Kiln shelves warping

Recommended Posts

I recently got a used electric kiln which I've been glaze firing to cone 5/6. The person who had it previously only fired low fire. I am noticing that the shelves are warping and i plan to wash the other sides and turn them over each time I fire from now on. My question is: are the shelves perhaps not rated to go to mid range? Should I eventually get new shelves? The kiln I fire where I teach has very old shelves that aren't warped at all...are they made for higher temps.?

Thanks!

Share this post


Link to post
Share on other sites

I can't help with the warping question, but do know that you shouldn't use a kiln washed shelf upside down -- kiln wash could flake off and fall onto your glazed work and ruin it!

 

 

just grind off ALL the kiln wash before turning it over. It shouldn't be all that hard to do.

 

Jim

Share this post


Link to post
Share on other sites

I recently got a used electric kiln which I've been glaze firing to cone 5/6. The person who had it previously only fired low fire. I am noticing that the shelves are warping and i plan to wash the other sides and turn them over each time I fire from now on. My question is: are the shelves perhaps not rated to go to mid range? Should I eventually get new shelves? The kiln I fire where I teach has very old shelves that aren't warped at all...are they made for higher temps.?

Thanks!

 

 

If they are half inch "clay" (corderite/alumina/some variation thereof) they really dont last at cone 6. You have to use a thicker shelf or a thin SiC shelf, if you can justify the cost.

Share this post


Link to post
Share on other sites

I've heard nothing but good things about hollow core shelves- CoreLite. Light and strong, and no more expensive than standard cordierite shelves. I got a few 14x28 recently, and they've held up well so far.

 

 

I knew someone recently who got a bad batch of those Corelite shelves, they were the largest they make for a round top-loader. Every single one cracked nicely down the middle--I saw her stack and posting--so did Resco the mfr). Resco insisted that it wasn't a manufacturing issue, but they were also completely happy to refund her $$$. I have encountered other folks with similar issues (but only with the very largest of shelves) and a tech @ Resco spoke to acknowledged that at one point they had issues with the extrusions being prone to cracking due to a an issue with either the die or the method by which they were cutting them, I forget. Either way he said it was resolved, but I sort of wonder.

Share this post


Link to post
Share on other sites

I've heard nothing but good things about hollow core shelves- CoreLite. Light and strong, and no more expensive than standard cordierite shelves. I got a few 14x28 recently, and they've held up well so far.

 

 

I knew someone recently who got a bad batch of those Corelite shelves, they were the largest they make for a round top-loader. Every single one cracked nicely down the middle--I saw her stack and posting--so did Resco the mfr). Resco insisted that it wasn't a manufacturing issue, but they were also completely happy to refund her $$. I have encountered other folks with similar issues (but only with the very largest of shelves) and a tech @ Resco spoke to acknowledged that at one point they had issues with the extrusions being prone to cracking due to a an issue with either the die or the method by which they were cutting them, I forget. Either way he said it was resolved, but I sort of wonder.

 

 

Interesting. Hopefully it truly is worked out. I tend to give them the benefit of the doubt, because if they didn't fix it word would get out quickly if the problem persisted. They HAVE to fix it to stay in business. The folks at Lill Street have been using them in their gas kilns for the last few years and they still haven't warped. Seems like every brand goes through some issues at some point. Thorley's went bad when Laguna first bought them out, but they got it figured out.

Share this post


Link to post
Share on other sites

I've heard nothing but good things about hollow core shelves- CoreLite. Light and strong, and no more expensive than standard cordierite shelves. I got a few 14x28 recently, and they've held up well so far.

 

 

 

I had one 21" crack clear across the middle first cone 6 firing, Standard Ceramic replaced it. After about a year, many 06 and just a few 6 firings two more just cracked clear across the middle on a 6 firing. They're light for a deep top loader, but I'm sure reluctant to try them again.

Share this post


Link to post
Share on other sites

I flip them about every other firing. Since I have a supply of the older 1 in shelves, I use the light weight ones higher in the kiln where it's hard to lift the others head high, getting too old and too slow to play like I was 50 :)

Higher is also a 1/2 cone cooler.

Wyndham

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×

Important Information

By using this site, you agree to our Terms of Use.