Monday, July 16, 2012

Bad Mandrels?

It's been a crazy depressing few weeks dealing with my kiln problems! The metallic luster has been vanishing from my beads and I can't figure out why. It seems to be getting worse and worse. I'm going to be sending the kiln back to The Glass Hive for rebuilding. Mike and Pam at Glass Hive have been really great in helping me solve this issue!

I've lowered my kiln temperatures all the way down to 820 and tested metallic beads, they still lost reduction. I bought a stand-alone pyrometer to test the temperature, and it was off by 50 degrees F, but even with adjustments the reduction was still disappearing. I've also tried activated charcoal, with no luck. Pam suggested my kiln might be contaminated.... but with what???

bad ole' rusty mandrels!
Bad mandrels???
She said iron pyrite, possibly introduced by low-grade steel mandrels, can contaminate the kiln and cause this problem. Also, if my kiln has been running 50 degrees hot, that could have caused more iron to vaporize.

I do have some very old mandrels... old ones that have rusted but I've scrubbed off the rust and kept using them... [insert peeking-from-behind-couch emoticon] and some really questionable hollow 3/16" mandrels that bent in the heat of the kiln.... omg... maybe this is why my problem keeps getting worse. We can't think of anything else it could be!

I haven't searched LE yet for threads about iron contamination, but Pam thinks she remembers someone talking about it there. Do any of you have experience with this?

My kiln should be back in a couple of weeks, all rebuilt... I'm sooooo excited. Hoping, praying, wishing that somehow this problem gets solved!

In the meantime I'm going through my THOUSANDS of orphan beads and having a "Christmas in July" sale on Etsy! My 11-year-old daughter sorted through all the orphans for me. She organized them according to design, like scroll beads, discs, spacers, encased, sculptural, etc. She was a huge help. I can't believe she did all that. I paid her! :)

More on the Christmas in July sale in my next post!


Jenni said...

that's bad luck..I have never heard of this before..hope you get it sorted.

Gardanne said...

A local welding supply shop cuts the mandrels for me, he said last time they have to be a high grade of steel because of their use in welding. My mandrels soak in water forever and never rust. Good luck with the kiln.

Karolen said...

I think I got a bad batch of mandrels about 10 years ago. Some of them are still in use in my studio. They did rust, just in the humidity of the air!

Lori Bergmann said...

I'm so sorry to hear about your ongoing problems and thank goodness the Glass Hive folks are so great with their customer service! I hope with the rebuild and some fresh, quality mandrels, your problem will be solved! *Ü*

Karolen said...

I hope so too, Lori!
I just put a thread on LE, in Tips and Techniques, asking if anyone has any ideas for me.

The kiln rebuild is such a generous and awesome thing for Glass Hive to do for me. I bet my kiln comes back working like it should.