Two questions

Hi Folks,

I have two widely varied questions… hoping for advice:

  1. I seem to recall someone stating recently that an ultrasonic
    should not be heated if sterling (or all silvers?) are being
    cleaned. Is this true? Can anyone confirm or deny?

  2. I’m finally getting a used dual lapidary arbor I bought last
    summer up and running (thanks to Wm. Mason for his help!). It
    runs two expanding drums, for which I have diamond belts. It
    seems the drums don’t expand sufficiently to hold the belts in
    place when they spin up. Granted the drums are used and have
    laid idle for at least 1.5 years… do I need new drums, or is
    there a suggestion for getting them to “loosen up” a bit? I’m
    sure they are rotating the right direction, as the drums are

Thanks in advance,


Dave Sebaste
Sebaste Studio
Charlotte, NC (USA)


Re: your expanding drums, if you are running them at 1750 or
close, they should expand enough to hold the belts. The question
that springs to mind is, are the belts the right size? If they
are too large they will not be tight enough. I had a 6" drum and
I used to run it at about half speed when cutting opal. The
belts held OK unless I pressed too hard and then they would
move. At 1750 (direct drive) they should hold — I think that’s
what they were designed for.

Roy (Jess)

Dave, I would try soaking the drums in hot water with a splash of
baby oil or mineral oil for half an hour or so - and then
running them up to speed (with a belt on) until they cool. No
guarantees, of course…but it’s worth trying before you invest
in new drums. Now you’ve got me thinking about my own used
lapidary arbor, which is collecting dust down in the basement.
It has a brand-new expanding drum on the right. I may just have
to go down and brush off the cobwebs after Christmas…
(There’s a newly-acquired jar of opal rough mocking me from my
bookcase. Can’t let that continue…) :wink:

Merry Christmas, Happy Chanukah & Happy New Year to the Orchid