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Pumice finish?


#1

Dear All, A customer has ordered three rings custom made in platinum,
and saw a ring at another jewelers that had a finish she wanted me to
duplicate. When she asked them as to the finish, she was told that it
was a “pumice” finish, which she described as giving the ring a more
antique look. I am unfamilar with the term, and would go look for
myself, however they are located about a thousand miles from me.

Have any of you run across this term before? I am in the middle of
remodeling my work area, and can’t lay my hands on my reference
books, so I am hoping someone out there will be more helpful than my
little dictionary, which tells me that pumice is “a light, spongy rock
used for cleaning”.

Thank you in advance,
JMF


#2

Hi Jon, Pumice it obsidian (volcanic glass) that contained gas while
solidifying from molten lava. I picked some up at Monolake,CA, where
it lays around everywhere, and use it to put a frosted finish on my
silver pieces. As opposed to sandblasting you get lines on the piece
and can play with it to achive parallel/star-shaped/circular
patterns. I’ve also recently read of grinding the stone into powder (I
just filed some of the stone off) and use it together with a glass
fiber brush and some detergent as lubricant. This way the finish gets
more subtle. Just be careful when handling the stone/powder, it is
basically frothy glass and the dust can settle in your skin and might
be irritating (although I had never had a problem with it).

I haven’t seen it in the Rio Grande catalogue, but drugstores sell
the pumice stones in the skin care section for filing off dry skin
from your feet ($2-3). It often conveniently comes on a little rope,
so keeping it handy is easy. These pedicure-stones are also natural,
but are a little softer than the material I got from the volcano.

Hope that helps,
Isabella


#3

Dear JMF, I can’t be sure what you customer wants but I use pumice to
finish jewelry. I either put it into a cheap tumbler or use a
toothbrush to apply it. The powder can be purchased in several
grades as most good woodworking suppliers. It gives a lovely
non-shiny satin finish that I would compare to bead blasting.

Pauline


#4

Hi Jon, Pumice finish can be many things, the lightest finish you can
actually get is with a charcoal block, rubbing it over the ring in
the same direction, following the flow of the shank. You can also use
ground pumice stone held in solution in a cloth always rubbed in an
up and down motion never in circles. Its a bit like the finish you
get when you have sanded a piece in the same direction, but lighter.
In fact a 3m scot/brite pad (fine) will do the job. It really depends
on what your client saw and without a reference it make it tough,
perhaps you could show some finishes on some sheet and let them
choose. The piece is always high polished first.

Ed Dawson
Maine Master Models
http://www.goldandsilversmithing.com


#5

Hi Jon,A pumice finish is obtained by mixing some pumice powder(cheap
and available by Rio Grande)with some dish soap to make a paste and
scrubbing the piece with a brass brush dipped in the paste.Its a
lovely soft finish,similar to a very fine sand blast.It does however
work better on a pendant as it wears off easily, especially if the
customer will have other rings next to it.Good luck with the
remodelling. Barbara


#6

Pumice is a glass that comes from explosive volcanoes. Its very fine
glass shards that are welded together during the process of cooling
down after the initial explosion. there are different grades of how
fine the pumice can be. Warning: just be careful since it is a glass
and very sharp. try to not breath it or rub it around to much. Try
to use gloves. Maria student(geology and fine art)


#7

Thanks for your info. May I add to it. Below is the MSDS for
Pumice - as you will note it is basically not hazardous but you would
not want to breathe large amounts of it by any means.

http://www.hesspumice.com/MSDS2001.htm

Kay