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copper matt

updated sun 29 feb 04


Charlie and Linda on thu 5 nov 98


I chased copper matt for 5 years before getting in. No one would help.

It is really easy. Just follow these steps and it will give you enough
to develop your own method.

Spray 3 coats on with an air brush. (I'm used the commercial formula
from A.R.T. company or a 90/10 blend) Mix as thick as will still pass
through the #3 or #5 tip on the air brush.

Spray a coat of hair spray on it to fix the powdery surface. Place
directly into the raku kiln to avoid multiple handlings and to minimize
finger prints.

Fire up to 1850-1900f and then cool the kiln to 1300-1400f.

Reduce as follows...

Prepare a bed of fine sand to use as the bottom of the reduction bed.
Select a reduction can that just fits over the piece with only 2" or
less to spare on the sides and top.
Mark a circle in the sand by pressing the mouth of the can in the sand.
Place a folded piece on news paper into this circle with no overhang.
Squirt a couple of table spoons of denatured alcohol on the paper.
Now you are ready to pull the pot!

When the temp. of the kiln reaches 1300-1400f pull the piece and place
on the news paper. Let it sit there and flame up for 20 sec. You
should see a black pot with swirling colors where the fumes and flame

Now cover the piece with the can and start a timer. If the can starts
to leak smoke then scoop up extra sand and pack it around the smoking
If it is a small piece (1 lb) reduce for 7-9 min. If it is a larger
piece then reduction may go as long as 12 mins.!!

Uncover and watch. If the color comes up slowly and turns bright then
cool with water to fix. If the color stays muddy then refiring almost
always fixes it.

Refiring is a given with copper matt. A potter that lives in NC always
glaze fires (with reduction) twice. It fixes the glaze and slows down
the fading that occures to almost all copper glazes.

Trouble shooting.

Muddy- Waited too long to open can or just needs that second firing.

Stays black- Didn't get enough glaze on.

Orange peel- Too much glaze.

Color shifts and then dissappears so fast that you can't cool it quick
enough to catch it.- Add extra time in the reduction can next time.

Remember- An open form like a bowl will loose heat quickly and takes
less time in reduction. A closed form like a bottle needs more time as
do really heavy pieces. A piece that is not uniformly trimed will go
quicker in the heavy areas due to the retained heat.

Good luck

Write if you need any more help,

Charlie Riggs

mystery boy on sat 28 feb 04

i was wondering if anyone had a recipie for a copper matt or copper lustre raku glaze thank you D C

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Gary Ferguson on sat 28 feb 04

This is one of my favorite:

Hawaiian Copper Blue
Gerstley Borate 80
Bone Ash 20
Copper Carbonate 5
Cobalt Oxide 2.5
Tin Oxide 1.3

Matt, Nice Blue to Copper Flashing, Glossy at higher temperatures.

Gary Ferguson
Raku Clay Artist
Nampa, ID 83687

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----- Original Message -----
From: "mystery boy"
Sent: Saturday, February 28, 2004 12:15 PM
Subject: copper matt

> i was wondering if anyone had a recipie for a copper matt or copper
lustre raku glaze thank you D C
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