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burnishing

updated thu 14 jul 11

 

Cynthia Blau on tue 10 dec 96

A potter friend without access to Clayart wants to know if there
is a slip she can burnish with a cloth rather than a stone. She
does a lot of burnishing and finds it hard on her hands. TIA.

Marcia Selsor & Matt Benacquista on wed 11 dec 96

Cynthia Blau wrote:
>
> ----------------------------Original message----------------------------
> A potter friend without access to Clayart wants to know if there
> is a slip she can burnish with a cloth rather than a stone. She
> does a lot of burnishing and finds it hard on her hands. TIA.
Tell her to use terra sigilatta. It is easy to buff.
Marcia in Montana
--
Marci Selsor
Matt Benacquista
http://www.imt.net/~mjbmls/
mjbmls@imt.net

Robert Speirs, M.D. 766 X4450 on wed 11 dec 96

I knew someone who burnished his pieces with great success by using a
cloth wheel on his grinder - you know, those wheels with many layers of
cloth that can be found in most hardware stores. He told me he was also
able to exert more pressure than you'd think against the rotating wheel
without damaging his pieces, which was my question to him. His
burnished pieces were gorgeous and evenly shiny birtually without any
wear and tear on his hand or arm from the repetitive movement usually
associated with rubbing a stone over the piece.

Lili Krakowski on wed 11 dec 96

I am confused here; several people I know burnish terra sig with cloth.
On the other hand when no terra sig is used a small stone (or a button)
is used as a burnisher to compact the clay and make it shiny. Does that
help?

Lili Krakowski lkkrakow@edisto.cofc.edu

On Tue, 10 Dec 1996, Cynthia Blau wrote:

> ----------------------------Original message----------------------------
> A potter friend without access to Clayart wants to know if there
> is a slip she can burnish with a cloth rather than a stone. She
> does a lot of burnishing and finds it hard on her hands. TIA.
>

Darrol F. Shillingburg on wed 11 dec 96

Hi Cynthia,

I do a lot burnishing also and use Terra Sigillata as well. Your firend needs to
learn to make and use the sigillatas. They are the closest to burnishing and can
be done with a cloth. They can also be stone burnished and oil polished. The
surface effect is not exactly like a burnished surface, but may be cose enough.
I often combine the techniques for effect or to reduce the time and energy spent
burnishing.

There are some common references to making sigillatas. If you have difficulty
locating them e-mail me your postal address and I will pass on to you a copy of
Vince Pitelkas (Appalachian Center for Crafts) wonderful workshop handout on
sigillatas. It's the best guidence I have seen anywhere in print and the
sigillatas produced under his instructions are consistantly magical. Credit
where credit is due!

Good luck with the "liquer of the gods".

Darrol in Elephant Butte NM

Vince Pitelka on wed 11 dec 96

>A potter friend without access to Clayart wants to know if there
>is a slip she can burnish with a cloth rather than a stone. She
>does a lot of burnishing and finds it hard on her hands. TIA.

Cynthia -
Your friend needs to learn about terra sigilatta. It is an ultra-refined
slip which polishes with a soft cloth to a very high shine when properly
formulated and properly applied. About six months ago I posted a lengthy
description of how I make terra sig. That post is now locked on the hard
drive of my old computer, which has a dead power supply. Until I get it
fixed I cannot access those posts. If someone out there saved that post,
please re-post it to the list or email it to me. It gives all the
information to formulate a good ultra-refined terra sig.
- Vince

Vince Pitelka - vpitelka@Dekalb.Net
Phone - home 615/597-5376, work 615/597-6801
Appalachian Center for Crafts, Smithville TN 37166

Sherri Borges on wed 11 dec 96

Try Bob Howell's teflon rib -- seems to work pretty well for me. And at $5
a piece, they're a major bargain, too.

Earlier message from Bob:
If anyone is interested I'd be glad to make some for you. Contact me
personally at the address below.

Bob Howell
bobhowell@linknet.net


----------------------------Original message---------------------
A potter friend without access to Clayart wants to know if there
is a slip she can burnish with a cloth rather than a stone. She
does a lot of burnishing and finds it hard on her hands. TIA.

william w. weaver on thu 12 dec 96

I to have been using terra sig for pots made with red earthenware clay. I
have found that burnishing with the back of metal measuring spoon usually
of the table spoon size seems to work well. I also burnishe shortly after I
apply the terra sig especially with colored sig's. On a few occasions I
burnishe when slightly dryer and seem to get a higher gloss. I would like to
know more about the tyes of cloth that peop[le have been using.

>----------------------------Original message----------------------------
>A potter friend without access to Clayart wants to know if there
>is a slip she can burnish with a cloth rather than a stone. She
>does a lot of burnishing and finds it hard on her hands. TIA.
>
>

Richard Burkett on fri 13 dec 96


William Weaver asks:
>>...I also burnishe shortly after I
>apply the terra sig especially with colored sig's. On a few occasions I
>burnishe when slightly dryer and seem to get a higher gloss. I would like to
>know more about the tyes of cloth that peop[le have been using.

Once again, this all depends on what you define as burnishing. If you're just
buffing up the terra sig, not really burnishing the clay surface with a lot
of pressure from a smooth object (I've found polished agate works even better
than stainless steel spoons), then using a piece of one of those crinkly
plastic bags that you get your groceries in these days works better than
cloth. This tip comes from Adrian Arleo, who uses a lot of terra sigs in her
work.

Richard

Richard Burkett - School of Art, Design, & A.H, SDSU, San Diego, CA 92182-4805
E-mail: richard.burkett@sdsu.edu <-> Voice mail: (619) 594-6201
Home Page: http://rohan.sdsu.edu/dept/rburkett/www/burkett.html
CeramicsWeb: http://apple.sdsu.edu/ceramicsweb/index.html

WHampton@aol.com on fri 13 dec 96

When I burnish Terra sig I use a cut off sleeve from a sweatshirt - inside
out using the fuzzy side
Wendy from Bainbridge island WA

ZALT@aol.com on sat 14 dec 96

I remember when I was a student, we waited until the piece was bone dry then
we applied one coat of ts and once it was dry we buffed the piece with a
supper soft piece of cotton cloth. Three to four coats in this manner was
sufficient to do the job.

If you had any marks on your piece they would not smoth out. the only way to
do this is by the traditional burnishing.

Best regards.
Terrance F. Lazaroff
St Hubert, Quebec, Canada !!!!

Bob Howell on sat 14 dec 96

(I've found polished agate works even better
>than stainless steel spoons), then using a piece of one of those crinkly
>plastic bags that you get your groceries in these days works better than
>cloth. This tip comes from Adrian Arleo, who uses a lot of terra sigs in her
>work.

The best thing I've used for polishing terra sig. is chamois. You can find
them with the car waxes at Wal-Mart, etc. Don't wet them and make sure you
get a real chamois and not the articial ones.

Bob Howell
bobhowell@linknet.net
Bob Howell
723 Terra Ave.
Alexandria, LA 71303
bobhowell@linknet.net

John Guerin on sat 14 dec 96

Clay body is made up of very small microscopic sized platelettes of material.
A good analogy would be if you spread a deck of playing cards out on a table
and poured water on them. They would stick together. Except in a clay body
the platelettes are not all parallel to each other, but are sticking out in
every direction. A very random mixture, if you will. A true burnishing action
such as would be achieved with a polished agate would compress the clay
surface and force the platelettes on the surface to line up and form a
reflective surface much like a mirror.
I prefer to burnish the clay surface while it is in the leather hard stage.
If the polishing stone leaves "tracks" on the clay surface, then the clay is
too wet. Another hour or two of drying time will allow you to polish(
burnish) the surface to a hard, mirrior-like finish. I learned this type of
polishing when I studied with the Acoma Indians. Most other cultures, such as
Hopi, Maricopa, San Ildefonso and Mata Ortiz potters let the pot go "bone
dry" and then apply an oil or grease to the surface and then do the
polishing. I have seen them use crisco, cooking oil and even hand cream
applied to the bone-dry pot so they could do the polishing. The oil burns off
in the firing and does not seem to have any effect on the final color.
However as I stated above, I personally prefer to polish with the moisture
still present in the leather hard clay.
If the moisture or oil is not present, even the smoothest polishing stone
will scratch the clay surface. A good way to finish off the polishing or
burnishing process is to buff the surface with a Chamois Cloth. They can be
purchased at auto stores where they are sold as drying clothes for after you
wash your auto. A Chamois Cloth is a very soft leather.


Good Luck, John Guerin
Instructor, Indian Pottery
Pima College
Tucson, Arizona

arlene h. on fri 17 sep 99

again my rookiness is showing. am i able to expect a burnished pot from an
electric kiln? would anyone mind to sum up the process for me? thanks
again.

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

Nina Jones on sat 18 sep 99

------------------
Hi, arlene:

Yes, you can fire a burnished pot in an electric kiln. It's just that you =
can't
reduce because introducing a reduction atmosphere in an electric kiln will
destroy the oxide coating on your elements causing them to burn out very
quickly.

Nina D. Jones
Southside Chicago
=40 njones=40winston.com


=3E=3E=3E =22arlene h.=22 =3Cchinacat54=40hotmail.com=3E 09/17/99 10:44AM =
=3E=3E=3E
----------------------------Original message----------------------------
again my rookiness is showing. am i able to expect a burnished pot from an
electric kiln? would anyone mind to sum up the process for me? thanks
again.

=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F==
5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5F=5=
F=5F=5F=5F
Get Your Private, Free Email at http://www.hotmail.com

Nanci Bishof on sun 19 sep 99

Coating the elements with ITC 213 helps protect the elements from oxidation
damage and allows a reduction atmosphere in an electric kiln.

nanci

In water-sogged. not very sunny north florida - but, Floyd did pass with
minimal damage! I'll settle for the dreary rain.

Naomi Rieder on wed 6 dec 00


Too many of my burnished pots, done when leather hard, are losing the
burnish, in small areas. The resuling loss is not just a dullness, but the
areas have a fine texture to them that I've been re-burnishing.

Can anyone suggest how to prevent this? Is it from too much air contact
while the pots are drying? Usually I cover the pots lightly with
dry-cleaning plastic bags, with the rims down. I've also tried covering the
pots, first, with cotton sheeting, then the plastic. Doesn't help.

A second problem is the bottoms: The bottoms are flat when I set the pots
rim down to dry, but after drying the bottoms are slightly bulged, so I have
to re-sand them.

Once again, much thanks for any help!

Naomi R

Snail Scott on thu 7 dec 00


Try re-burnishing when much drier. If they are still only
leather hard for the final burnish, the continuation
of the drying process itself is dulling your surface.
The best results often involve re-burnishing several times
throughout the drying process. Many people even burnish
when completely bone-dry, for a perfect surface. This can
be facilitated by wiping the surface with mineral oil or
water or both alternately, just before the final burnish.

-Snail



At 11:33 PM 12/6/00 -0500, you wrote:
>Too many of my burnished pots, done when leather hard, are losing the
>burnish, in small areas. The resuling loss is not just a dullness, but the
>areas have a fine texture to them that I've been re-burnishing.
>
>Can anyone suggest how to prevent this? Is it from too much air contact
>while the pots are drying? Usually I cover the pots lightly with
>dry-cleaning plastic bags, with the rims down. I've also tried covering the
>pots, first, with cotton sheeting, then the plastic. Doesn't help.
>
>A second problem is the bottoms: The bottoms are flat when I set the pots
>rim down to dry, but after drying the bottoms are slightly bulged, so I have
>to re-sand them.
>
>Once again, much thanks for any help!
>
>Naomi R

Kurt Wild on thu 7 dec 00


At 11:33 PM 12/06/2000 -0500, you wrote:
>Too many of my burnished pots, done when leather hard, are losing the
>burnish, .........

In my experience, generally pots burnished in the leather hard stage do
tend to lose the burnish unless they are burnished in the hard leather hard
stage. Can't answer the why of losing burnish in spots.
Why not try burnishing bone dry pots - a technique I have followed and
learned from Michael Wisner which has been published in the book The Many
Faces of Mata Ortiz as well as in a Ceramics Monthly article (see below).

Hopefully the following information for polishing is just what you're
looking for. If you would like more information on the subject check out
the article "The Spirit to Learn, The Spirit to Teach" which was published
in the November 1999 issue of Ceramics Monthly. I also have two other
items on the subject that were posted by people on the internet newsgroup
Clayart.

Basic polishing (also refer to page 192 in The Many Faces of Mata Ortiz:
The pot should be very dry.
Sand with #100 sand paper then sand with #220.
Blow off excess dust.
Apply (soft brush or soft rag) an even coat of baby oil.
Allow a few minutes to soak in.
Take a damp soft cloth (T shirt) and rub in a circular motion.
Lightly wipe (swipe) in a straight (down) fashion.
Burnish with a polished stone or highly polished metal or glass rod.
I understand Juan used a polished piece of deer bone.

Michael Wisner, says that Juan Quezada says that "polishing in itself is an
art you can spend a
lifetime perfecting".



Kurt

email: KURT.L.WILD@uwrf.edu
website: http://wwwpp.uwrf.edu/~kw77

vince pitelka on thu 7 dec 00


> Too many of my burnished pots, done when leather hard, are losing the
> burnish, in small areas. The resuling loss is not just a dullness, but
the
> areas have a fine texture to them that I've been re-burnishing.

Naomi -
This will always happen if you burnish when leather hard. A burnished
surface is so compressed that it has no capacity for shrinkage, and if
forced to shrink (from leather-hard to bone-dry) it will crinkle on a
microscopic level, leaving a matt surface. Let your pots get bone-dry, and
then coat them with grease (lard or vegetable oil or crisco), let that soak
in a bit, and then burnish them. Or, for the very best finish, make a terra
sig out of your claybody or out of the desired colored claybody, paint on a
few coats of that, let them soak in, then apply the greas, let that soak in,
and then burnish. That will give you the best glassy finish.

For the smoothest surface, sand the pots when dry, and then apply six to ten
flowing coats of terra sig, let that soak in, but while still damp coat with
the grease, let that soak in, and then burnish to your heart's content. The
grease prolongues the moisture so that you can continue burnishing as long
as you with without problems wiht flaking. It also makes a harder surface
more likely to survive unscathed until the firing.

Remember that a true burnished (polished with a hard smooth object) cannot
be fired any higher than about cone 014 or cone 012 (dependent on the
claybody) or it will loose the shine, for the same reason as above.
Best wishes -
- 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/

WHew536674@CS.COM on thu 7 dec 00


Naomi,
Try this on a test piece and see how you like it. Wait until the piece is
totally dry. Take vegetable oil, and cover the piece with it. After it
soaks in, take a damp sponge and dampen an area that you are going to
burnish, then start burnishing. I have found this to give a "glistening"
shine that you can almost see your face in. The best part of it all is that
it only requires one application of burnishing.
Joyce A

Snail Scott on tue 25 sep 01


At 10:11 PM 9/24/01 -0400, you wrote:
>If you need to burnish a bone dry pot (porcelain) and don't have time to
>research and make up a terra sig, is it still possible to burnish
>successfully? Should the piece be lubricated in some way...say with oil?
>Thanks--
>----Gail



Yes (and yes)!

I use a nice rock and baby oil.

-Snail

Jonathan Pennington on sun 23 dec 01


* Bun Bun [011223 09:19]:
> Can anybody tell me what the highest temperature I can fire a burnished
> piece before it will no longer shine?

Trying to answer questions once in a while instead of only asking. I
think that about 900deg C is the limit. I usually fire my burnished
earthenware to about 800-850C at the high end, I don't want to go
higher than that incase the kiln overfires or something. I tend to
keep a nice shine on it at 800, maybe it could be better, I'm not
experienced enough to know.

-J
--
Jonathan Pennington | jwpennin@bellsouth.net
"There are no pots, there is only clay." -original
"It's hard to take life too seriously
when you realize yours is a joke." -also original

Bun Bun on mon 31 dec 01


Can anybody tell me what the highest temperature I can fire a burnished
piece before it will no longer shine?

_________________________________________________________________
Send and receive Hotmail on your mobile device: http://mobile.msn.com

vince pitelka on tue 1 jan 02


Original Post:
"From this list I have learned ^08 is the highest, so I bisque my burnished
pots at ^09. I use medium fire clays, maturing at about ^6."

Actually, for a stone burnished piece, ^08 is too high. Polished pieces,
where the shine is developed by rubbing with plastic sheeting, chamois, or a
soft brush, can be fired up to ^08 or higher (with a gradual diminishing of
shine). But pieces which are truly burnished by rubbing with a hard,
unyielding object cannot be fired above ^012 or perhaps an absolute limit of
^010. A burnished surface has absolutely no capacity for shrinkage, and of
course this depends some on your particular claybody. Some clays will start
to shrink quite early, and it does not take much to ruin a burnished
surface.
Best wishes -
- Vince

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

lela martens on tue 1 jan 02



From this list I have learned ^08 is the highest, so I bisque my burnished pots at ^09. I use medium fire clays, maturing at about ^6.   Lela



>From: Bun Bun
>Reply-To: Ceramic Arts Discussion List
>To: CLAYART@LSV.CERAMICS.ORG
>Subject: Re: Burnishing
>Date: Mon, 31 Dec 2001 17:00:56 -0600
>
>Can anybody tell me what the highest temperature I can fire a
>burnished
>piece before it will no longer shine?
>
>_________________________________________________________________
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Allyson May on sat 24 apr 04


Hey Cat,
You are right, everyone will have their own personal method of =
burnishing. Having said that, listening to all of the various methods =
and then finding the right combination for yourself is the way to go. =
Generally a good burnishing tool will work on most any clay smooth or =
grogged. Rubber ribs are a good way to push the grog into the clay and =
then your preferred burnishing tool can be used. I have found that =
metal objects such as spoons will leave dark streaks on light colored =
clays and the streaks do not fire out. (side note: I burnish at the bone =
dry stage) After using many different polished stones I have settled on =
hematite. It is dark silver, almost a pewter look when polished. I =
pick them up in novelty shops or souvenir shops where other polished =
agates are sold. These stones burnish like magic and do not leave =
streaks of color. Another great polishing tool is a bone folder used =
for folding papers. These also leave no color streaks on light clay. I =
have just completed a workshop where the presenter burnishes all of his =
works. Their finish was so silky that we asked for a burnishing demo. =
His burnishing tools are light bulbs of various shapes and sizes. His =
clay does contain fine grog but the light bulbs seemed to push the grog =
into the leather hard clay while burnishing the surface to a nice smooth =
shine. I will try this method on my next project. Good luck on your =
search for info and keep burnishing! There are not many of us out there =
who have the patience to produce a fine burnished surface.
Peace,
Allyson May
Stoney Creek Pottery
Bloomington, Indiana

Logan Oplinger on mon 26 apr 04


Hello Allyson, Lynne, William, and Others,

If I am going to burnish a piece of clay, I usually use the following steps:

1. Smooth the soft clay surface with a rib, stiff & straight for flat
surfaces, flexible for curved surfaces. If I want to retain the ridges and
valleys made by my fingers on thrown pieces, then I skip this step.

2. When soft leather hard a polished flint or chert river stone is used,
rubbing against the clay just hard enough to push bits of grog/sand down
into the clay, but not hard enough to distort the surface. The flatter the
surface I want, the flatter the stone I use. For concave curves )( I use a
more rounded stone to fit the curve.

3. When "hard leather hard", or just before the surface begins to change
color from drying, the first "rough polishing" is done, being careful not
to push too hard against the clay.

4. When the clay is almost dry, I rub vegetable oil onto the surface with a
soft cloth or brush. The oil is allowed to soak in completely, and the
surface is given a second polishing with a stone.

5. A third and final polishing is done after the clay is completely dry and
the surface oiled lightly again, allowing the oil to soak in completely.

If I want to smooth or burnish the inside of a pot, I use a polishing stone
with a knob glued to one side. This knob can be anything which is
comfortable to hold between the thumb and first two fingers (another small
stone, a glazed clay bead, etc.). For working inside handles and spouts,
or under rims, I have glued two small polished stones about the size of
marbles to the ends of a short piece of 1/4 inch dowel, one at the very end
and one at the side of the end.


Logan Oplinger
Another Tropical Island
13 deg. 24 min. N. Long., 144 deg. 47 min. E. Lat.

Christine Martin on sat 16 apr 05


i've read a few posts on this and it reminded me of a picture i have in a
book. i love the smooth finish without glazing. in the description on the
picture it says that it's done with a smooth round rock but no detail is
given on how to go about it. can anyone explain to me how this is done? i
assume it is done before bisque firing?

christine

Marta Matray Gloviczki on sat 16 apr 05


dear christine,

i am sure you are going to get some helpful advice
here on clayart from our generous members who are experts
in burnishing, but may i recommend you an excellent book
written by one of our gurus,
vince pitelka: clay / a studio handbook
isbn 1-57498-090-4
and you will learn a lot from it, not only about
burnishing, but about clay in general.

cheers,
marta

you wrote: >>>>>>>>i've read a few posts on this and it reminded me of a
picture i have in a book. i love the smooth finish without glazing. in the
description on the picture it says that it's done with a smooth round rock
but no detail is given on how to go about it. can anyone explain to me how
this is done? i assume it is done before bisque firing?

John Kudlacek on tue 19 apr 05


Hi Christine, I am not pouring through all of the posts relevant to your
requesst but offer you this: Burnishing and sawdust firing was a required
project for my begining students.
We followed this procedure:
1. Scrape then trowel the leather hard surface smooth.
2. Using the back of a metal or plastic spoon burnish the surface with a
circular motion.( If the clay is too soft or if you use too much pressure
unwanted rigids will form.)
3. Allow the piece to dry. This shine will disappear* but you have
prepared the surface well for later burnishing. Reburnish by dampening an
area about the size of a nickle. Avoid too much pressure which may
scratch the surface. At times we used a miniscule amount of vasilene on
the surface of this burnished piece and did a third light burnish.(do not
be confused by a "grease shine" with a true, permanent, burnished shine.
Wipe with a soft cloth to make sure all of the surface grease is gone.) A
final rub with the hands seems to add even more luster.
4. Clay type is important. Some respond well others don't. Avoid coarse
or grogged clay.
Check with the other posts which I am sure deal extensively with terra
sigillata
*Apparently solubles migrating to the surface upon drying kill this shine.

Pete Horridge on sun 10 jul 11


I recently burnished a new clay that has a high Molochite content. I used=
=3D
the=3D20
back of a spoon and was surprised to see it left dark marks across the su=
=3D
rface=3D20
of the leatherhard pot and when bisque fired it gave a slightly orange/br=
=3D
own=3D20
shade.

When raku'd with a transparent glaze I noticed that the finish was slight=
=3D
ly=3D20
grey, almost as if my kiln had had a reduction effect. With my normal cla=
=3D
y=3D20
(less grog), the same process results in a smooth transparency showing th=
=3D
e=3D20
white clay body. This seems to suggest that my normal oxidising firing is=
=3D
=3D20
getting oxygen from the glaze/clay body more easily than its normal sourc=
=3D
e;=3D20
i.e. the inlet port around the burner nozzle? But only for the clay with =
=3D
the high=3D20
grog content?

I have started using a smooth pebble for burnishing and so far the result=
=3D
s=3D20
seem good although I am waiting for my pots back from Bisque firing at lo=
=3D
cal=3D20
college's kilns.

The reason for the posting was to ask:

'What is your preferred burnishing tool/method and have you noticed that=3D=
20=3D

different clay bodies need different approach?'

Many thanks

Pete

Allyson May on mon 11 jul 11


Hey Pete,

I used to use metal objects to burnish with but ran across the same =3D
problem you have described. Sometimes I would get silvery black streaks =
=3D
after the final firing which were definitely tracks or residue left from =
=3D
the metal burnishing tool. I also had issue when I burnished my work =3D
with a hematite stone. Hematite is also known as blood stone and after =3D
the final firing the burnished areas were pink with red streaks...oops. =
=3D
Friction causes the tool to transfer some of its self onto your work. I =
=3D
burnish at the bone dry stage so the transfer of material from my =3D
burnishing tool to the pot surface is much more pronounced than if I =3D
burnished at leather hard. The more sandy/groggy the clay the more =3D
transfer. I now burnish with polished quartz or other agates that don't =
=3D
cause streaking. You can also use plastic spoons or polished bone such =3D
as a bone paper folder. Hope this helps.

Peace,

Allyson May
www.stoneycreekpottery.com

Pete Horridge on mon 11 jul 11


I should have engaged brain before starting to type!

I have just tried the 'Search' tool and discovered a number of previous=3D2=
0=3D

postings regarding burnishing, which I will now work my way through.

Kind regards

Pete

Snail Scott on mon 11 jul 11


On Jul 10, 2011, at 3:55 PM, Pete Horridge wrote:
> I recently burnished a new clay that has a high Molochite content. I =3D
used the=3D20
> back of a spoon and was surprised to see it left dark marks across the =
=3D
surface...



Clay with sand will do this, too. What you are seeing is
the steel of the spoon being scraped off onto the clay.
(You have just added iron content to your clay surface.)
You will likely observe scratches on the spoon, too. It's=3D20
common enough that I lead my class through the thought=3D20
process as soon as someone notices it happening to=3D20
their project (and it will...). Students who chose to burnish=3D20
with rocks or other things compare with the various spoon=3D20
results. (It also shows the huge difference between the=3D20
various grades of stainless-steel flatware!)=3D20

-Snail=3D