slipping moly element

[Virgil Jones]

So here's a new one on me.

In checking the furnace top of my Stadelman as I walked by two days ago I notice one of the elements wasn't sticking up as far as the others. I looks like, after three+ years of use, the clamp/holder has loosened and the element has slid down 1-2 inches. Apparently what is holding it now is the braided connecting straps. It has slipped down so that the element straps are resting on the diplag...which is resting on the element clamps. Amazingly, it's still running fine.

I'm not quite sure how to raise the element back up and tighten the element/clamp again. Taking the element out and, at room temperature, readjusting it seams iffy given how fragile these are.

I'm also concerned about the thick/cool part of the element being exposed to the heat of the furnace.

Anybody have experience with this.

[Eric Hansen]

Hi Virgil,
I've had one do that but not slip all the way down to the connection. Mine slipped down about an inch, more than that on one side so it was warped slightly. I just tightened it up, too risky to raise, and I've been lucky for months now. Seems to be ok even with the thick part in the hot zone more than it should be. I don't suppose the nuts are backing off, just expanding from from the heat?

[Mark Rosenbaum]

Have you been checking and tightening them on a regular basis?

[Virgil Jones]

I've been tightening the straps at all connections and the transformer connections. Just never considered tightening the clamps...go figure. So I will be from now on. Just interesting after 650+ charges it finally slipped.

[Pete VanderLaan]

I would shut everything off, get up there and first loosen the clamp bolt,gently raise the element. Then using your third arm, tighten the bolt on the clamp. It won't damage the cold zone to be down in there but it could overheat the straps to be down so far.

I did have it happen once and the element actually contacted the crucible. I did not have a kill switch on the furnace door but it all went off to the infinitely more attractive ground. I did move it.

[Mark Rosenbaum]

I've been tightening the straps at all connections and the transformer connections. Just never considered tightening the clamps...go figure. So I will be from now on. Just interesting after 650+ charges it finally slipped.

650+ charges!!! Boy, I'm impressed! How big is your furnace? How often do you charge?

[Virgil Jones]

650+ charges!!! Boy, I'm impressed! How big is your furnace? How often do you charge?

Thanks, Pete.

Mark, I've got an electronically beefed-up 100lber. I charge sometimes 3, but usually 4-5 times a week...anywhere from 42 to 48 weeks each year. It's part of the reason I've been building a 400lb moly furnace. I've been very impressed with the durability of the little Stadelman...great tool.

[Pete VanderLaan]

The 400 lb furnace for virgil has a souped up electrical package running I think about 32KW or close to it. I overbuilt the components.