Feeling Like an Idiot - Watch Your Firing Times!

[Hyn Patty]

 

A while back I mentioned on my Workshops Facebook group that my large Skutt kiln cost a small fortune in electricity to fire and that a newer kiln wouldn't have that issue.  Which turns out to be true - in a simplified way.   A long firing using my Skutt after 20 years was taking too long and eating a lot of power.   It might run me $50 in electricity to do a single long, slow firing and that's nuts. I had no idea until my husband commented on how much our power bill had jumped up when I started using that kiln again.   But for a while I had used this kiln so little until the past year that I forgot how long the firing schedule should have been.

While firing a Cybis 'Nashua' I've been working on for a while, one evening my kiln finally threw an error code and aborted the firing.  Thankfully my client's Cybis wasn't ruined.  It merely didn't fire up to temperature.  Either one of my kiln elements had blown or my thermocouple had gone bad.  Testing was in order.  A simple multimeter (while the power was disconnected) showed me a LOT of resistance in the elements that still worked.  I then ordered new elements for my Skutt and they arrived yesterday!  Mind you, BOTH of my kilns have been used much of the past 20 YEARS and NEVER had anything replaced on them until last year.   My Skutt especially still looks brand new and I try to keep both kilns in top condition, but....  My Olympic suddenly blew a relay last year and that was a wake up call for me!  Now this.

Needless to say I should have replaced the relays and elements YEARS ago.  Expensive as they are I've surely wasted several times the cost in electricity in just the past few years due to having worn out elements and not realizing it.   All my firings have continued to go just fine - I just wasn't keeping a log of how long it took for those firings.  If I had been I'd have seen that my firing times were getting longer and longer over the years.  It did that so slowly I didn't even notice.  I barely even use this large Skutt kiln compared to my little Olympic Doll E so why would I have caught that?  Now I feel stupid for not catching it sooner.

As I am fond of saying, 'No matter how much you think you know about anything, there is ALWAYS more to learn!'  Ceramics is definitely no exception to that rule.  So guess what I am doing today?   Replacing all four elements in my Skutt.  I've got this!  There's a YouTube video for almost anything out there...

 

[Hyn Patty]

Oops!  I should have posted this in 'Equipment Use and Repair' so if a kindly admin would move it for me, I'd appreciate that.  I'm looking but I do not see a way to move it myself.  Thank you!

[neilestrick]

Moved.

Good catch! You'll be much happier with the new elements.

New kilns and old kilns only differ in cost of firing if they have different brick thickness. 2.5" brick used to be the standard on older kilns, with the exception of 28" wide kilns. Now 3" is the standard on all sizes for the most part. Some manufacturers don't even offer 2.5" brick any more.

I once did a test to see how much firing costs change as elements wear. I let the elements in my L&L e18T-3 wear until they could no longer reach cone 6, and the firing cost was double that of a new set of elements. On my kiln that was an extra $9 per firing. In a 10 cubic foot kiln it could be $25 per firing. So definitely keep those elements fresh. Once the resistance has changed by 10% from new they are due for changing. A cheap multi-meter is definitely worth the investment to be able to check element resistance every now and then.