Stuck vulcanizer

Hi all,

Today I was happily vulcanizing away. The buzzer went off on the
timer, I go to open the vulcanizer, and can’t to it. All of us try,
no one can open it.

I wasn’t vulcanizing anything unusual. It’s an old vulcanizer,
nothing fancy. Wheel type handle on top. Brand is Pro Craft or
Craft Pro.

I’m hoping someone will post and say, oh yes, Elaine, that’s a
standard vulcanizer problem, just do this and it will magically

It’s really, really stuck. The strongest among us cannot open it.

And if it’s not salvageable and you have a cheap, used vulcanizer
for sale, do email me!

Elaine Luther
Metalsmith, Certified PMC Instructor

Hard to Find Tools for Metal Clay


I use to manufacture one just like that. This Procraft was made by
REY (a division of Swest)

The Wheel has a quarter turn before it starts lifting the top

If it is stuck it is not because of the plates.

Sounds like the threaded shaft is stuck in the Yoke.

  1. It could be because of the two Guides on either side of the
    threaded shaft . (Bent may be)

  2. Something got baked on the threads between the Yoke and the
    Threaded Shaft.

I would turn on the Vulcanizer let it heat a little and try again.

If that does not help let me know.

Kenneth Singh


Try using some liquid wrench soak the threads on the spindle for 12
hours, try opening , if there is some way to achieve better leverage
use a 2 foot pipe then gently force it . If this does not work try
using a torch to heat the surrounding metal till you can turn the

Good luck Sam

Hi Elaine,

This has ha-ppened to me. Our vulcanizer doesn’t have the best
machined threads. When it is cranked down really tight on a thick
mold, the rubber expansion is enough to to through the alignment off
to the point getting it jammed. I then have to spray a lubricant or
release agent and let it soak the threads. Then I have one of the
guys crank it TIGHTER, then back off, jiggling until the threads
realign and permit free movement.

To avoid this problem, I do not tighten to the point of NO PLAY.
I tighten and then make sure to back off a little. This seems to
compensate for the rubber expansion while not jamming the threads.

Hope this helps.
Donna Shimazu

Dear Elaine,

Have you tried a penetrating lubricant such as “Liquid Wrench” or
even WD40 on the screw threads?

If all else fails you could just disassemble the two side posts.
Typically they are held on by large nuts at the top or perhaps inside
the machine base. You may have to remove a cover plate under the
base, but that’s simple.

Michael Knight
CASTALDO(r) Products Mfg. Corp.

Similar to what happens with the students using vulcanizers.

Usually I tell them to let the vulcanizer cool for 10 min. or so.
The cooliing down time allows vulcanizer and mold frame to
un-expand, reducing the pressure on screw threads, and vulcanizer
will then open.

I have had many problems with stuck vulcanizers. The trick it seems
is to tighten initially and every few moments jiggle the wheel (don’t
really loosen the wheel, but just move it so it doesn’t become
stuck). After the first 5 minutes or so it seems not so necessary. I
think the expansion of the rubber in the mould causes the wheel to
become stuck. Different brands of silicone/rubber behave differently
in this respect.

Fr. Alexis Duncan