iandol on thu 21 dec 00

I think there is some confusion about the use of this tool. I have a =
professional Dremel, the sort that hangs on a sky hook and is governed =
by a foot peddle. This is not a burnishing tool used with any buff or =
polishing head. Yes, there are hundreds of widgets which fit it. But =
they are for grinding, routing, cutting, polishing such firm materials =
as metal, glass, wood, plastic, gems and bone. Relatively unyielding =
materials when compared to Terra Sig.
There are some excellent jewellers tools which you may be able to lay =
your hand on. They are made from hardened polished tool steel. The =
technical term is Burnisher. I have several and one of the best would be =
in the form of a polished rod about 5mm diameter, ground and polished to =
a needle point at one end and to an attenuated spatulate form at the =
other so that there is a convex surface and a concave surface which =
narrows down to a sharp point. And, as with any hand craft skill, =
learning to use it takes time and application to a specific job takes =
patience.
A Merry Christmas everyone.
Best regards,
Ivor.

Cindy Strnad on thu 21 dec 00

Martin,

I don't know if I'd want to dip leather hard pieces several times in terra
sig. The bottom might fall out. The way I've done it is to paint on the
terra sig at bone dry. The sig will only be as flawless as the surface you
apply it to, so you'll want to sand carefully. Use as many coats as seem
necessary, as Vince said, 8-10. You paint on a coat, and when it's fairly
dry, paint on another coat, etc. I expect you could dip as well, but let
them dry a bit in-between. They polish beautifully with a thin bit of
plastic film over your finger, as you've been doing.

If you don't need the extremely refined surface of terra sig, you can
burnish the base of your pots on the wheel when you finish trimming them (at
leather hard). All my higher fire pots get this treatment--just use a spoon
and burnish as the wheel spins. I seldom foot a pot, but I always burnish
the bottoms. If you've only been applying one coat of sig at leather hard,
this may give you nearly as smooth a surface as the sig does.

Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
earthenv@gwtc.net
http://www.earthenvesselssd.com

vince pitelka on thu 21 dec 00

> So that is where the problem is. I dip the pot just once in terra sig at
> leather stage and then wait until it will take a shine. It does, but it
> takes time. So dip several times? We'll see what happens. If the bottom
> falls out ...

Martin -
I have never had any luck at all getting a really good shine when the terra
sig is applied to leather-hard pots. The piece will shrink additionally of
course as it dries, and this will disrupt any shine you have achieved. That
is the primary advantage of applying sig to the bone dry piece. When you
apply a number of coats of sig, it reintroduces enough moisture to allow you
to shine the piece, but the shrinkage has already taken place, so the shine
is preserved.

With even a very thin piece, and with proper care, you can apply plenty of
coats of sig in order to get a very high shine. When I make pinch pots with
my intro students I like to make egg-shape pots that are about 1/16" thick,
and when dry I sand them smooth before applying the sig. One must be very
careful applying terra sig to such thin pots, but it is possible, and I like
the results.
Good luck -
- Vince

Vince Pitelka
Home - vpitelka@dekalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
http://www.craftcenter.tntech.edu/

Snail Scott on thu 21 dec 00

At 01:04 PM 12/21/00 +1030, you wrote:

>There are some excellent jewellers tools which you may be able to lay your
hand on. They are made from hardened polished tool steel. The technical
term is Burnisher. I have several and one of the best would be in the form
of a polished rod about 5mm diameter, ground and polished to a needle point
at one end and to an attenuated spatulate form at the other so that there
is a convex surface and a concave surface which narrows down to a sharp
point. And, as with any hand craft skill, learning to use it takes time and
application to a specific job takes patience.
>A Merry Christmas everyone.
>Best regards,
>Ivor.



I use my burnisher for metalwork, setting bezels and the like,
but for clay I prefer smooth stones. I found that the point of
a jeweller's burnisher is not convenient for most clay shapes
that I make, and I constantly risked gouging. Also, unless kept
dry, the steel burnisher will get rust spots, which roughen the
surface.

I use smooth stones for burnishing gold leaf, also. (For this, a
hematite or agate set in a handle is traditional, but I don't do
so much of it that it's worth making the handle.) The shape of
such burnishers is called a 'dog's tooth', but actual canine teeth
aren't really used anymore.

For terra sigillata, though, a chamois works better than things
that apply too much localized pressure, IMHO.

-Snail

Snail Scott on thu 21 dec 00

At 02:05 PM 12/20/00 -0000, you wrote:
>Vince wrote:-
>>dry, sanded pot, and that is what takes the time. After that, polishing
>only takes a few minutes.>
>
>So that is where the problem is. I dip the pot just once in terra sig at
>leather stage and then wait until it will take a shine. It does, but it
>takes time. So dip several times? We'll see what happens. If the bottom
>falls out ...
>
>Martin Howard

I also apply it to leather-hard clay and wait to
burnish. I do apply multiple coats, though. With
me, it flakes too much from shrinkage when applied
to dry clay. How do you do it, Vince?

-Snail