PMC Porosity

Jewelry Discussion
1

Jim and Helen,

Thank you both for the I understand, and now wonder if
tumbling helps in any way?

BTW, I changed the spelling, but just thought it may be the Queen’s
English spelling. It just hurt my eyes, and my fingers just had to
do it. sorry Helen, et al.

Hugs,
Terrie

2

Terrie,

Tumbling will not change the internal porosity of the material,
however it will close off surface pores somewhat. It will also
compact and burnish the surface making the silver appear shiny.

This is not to be confused with a “mirror finish”. Although the piece
will be shiny, tumbling will leave a faint “orange peel” texture if
you look closely. A smooth mirror finish is achieved through sanding
and polishing. (again, this does not impact the basic porosity of the
material, just it’s appearance.)

Pam East

3 
Thank you both for the I understand, and now wonder
if tumbling helps in any way?

Yes it will harden and burnish the top layer (a few microns) of the
PMC which will close up the surface porosity.

Jim

James Binnion
James Binnion Metal Arts

4

Hi, Terrie,

wonder if tumbling helps in any way?

Tumbling may close some or most of the surface pores, depending on
what material you tumble with. You might want to review the Ganoksin
workbench tips on metal clay, if you haven’t already:

Search engine: http://www.ganoksin.com/orchid/archive/

For any parts that will need to be soldered to findings, etc, it
would be wise to close the surface pores first with a burnisher, as
PMC absorbs a lot of solder.

Cheers,
Lorraine

5 
Yes it will harden and burnish the top layer (a few microns) of
the PMC which will close up the surface porosity.

Yes, and this is why it is important to heavily burnish any silver
clay that you intend to solder–if you don’t the solder just flows
down into the porous metal. For more on PMC density, see

http://www.pmcguild.com/gettingstarted/technicaldata.html

Mary Ellin D’Agostino, PhD
www.medacreations.com
Sr. Teacher, PMC Connection
Certified Artisan, PMC Guild

6

Hi Jim,

The real difference in weight is exhibited by PMC Original
(Standard) and, yes, it is noticeable. With PMC+ and PMC3 it is not
as obvious, of course, because these two formulae are a little more
dense. Sorry I didn’t mention that in my previous message.

I don’t know about Art Clay products (someone chime in please).

Linda Kaye-Moses

7

Linda,

Art Clay Silver is similar in density to PMC3 and PMC+. Just going
by weight, I would not be able to tell the difference between a fired
piece of PMC3 and Art Clay just by picking it up. Standard PMC I can
usually tell.

Pam East