Burnishing - not glazing | POTTERS and MUSES

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Burnishing - not glazing

Does anyone have experience with this? I always thought burnishing was beating the clay lightly with a tool to get a polished surface and then glazing?? What do you think?

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posted by pcalenda

Hello, Peggy,

I used to burnish most of my terracotta way back when, rubbing with a polished agate, with most satisfactory results - sorry, can't find pics! Nowadays, I burnish exposed surfaces on most stoneware pots, usually with a stainless steel spoon, which adds a very fine layer of iron to the surface. At >10, this burnishing doesn't produce the gloss of lower temperatures, but does leave a very pleasing smooth, somewhat lustrous surface with some extra, slightly metallic colour. This also works fine leaving traces of high iron content glaze on the surface to be polished, and in this case I usually get a definite silvery lustre in reduction firing. If I don't want the added colour, I use a stone.

Never tried terra sigilatta, but am tempted to give it a go!

I'm uploading a picture of a >10 pot with stone-burnished rim.

posted by Scottargie
over 2 years ago

I've done terra sig and burnishing. You get a nice effect with salt firing in low temp with the burnished surface. I have also done it with pit firing.

posted by mudqueen
over 2 years ago

The Horsehair pots on my profile are burnished porcelain. I also use a spoon but from time to time get lazy and the edge would gouge the pot so most of it is done with river stone or the best is a pyrex test tube or lab bowl. Very hard smooth surface that holds up to the abrasivness of the clay. We usually did it for horsehair, naked raku and ferric treated pots.

posted by playsnmud
over 2 years ago

So burnishing works better in other than electric kilns?

posted by pcalenda
over 2 years ago

I did a burnishing technique in a Duncan certification class. It involved putting underglazes on greenware and using a small piece of terry cloth to burnish the surface. It has been many years, but I believe that it may have involved the use of water, spraying the surface of the underglaze to dampen it very slightly, then polish like mad. It was time intensive, but produced an attractive, slightly textured matte finish. I did this on a vase and the inside was glazed so that it would hold water. This was done with earthenware slip and relatively low firing temperatures (cone 05½ glaze firing). I never tried it again on my own.

posted by collieflower
over 2 years ago

The stuff I make is low fire, ^06 temps or less. Whether you use electric or gas isn't a big issue. THe horsehair pots were burnished then bisqued to ^06 and then later heated to around 1000 F just to get them hot enough to ignite the horsehait and leave the carbon trail.
They wind up being rather fragile.
Pit fired and sagger pots go through different firing schedules but result in some great burnished appearances..

posted by playsnmud
over 2 years ago