Archive for the Category ◊ Glazes and Slips ◊

11 Jun 2010 Charlie’s Home Brew Terra Sig’
 |  Category: Glazes and Slips  | Tags: , , , , , ,  | Comments off
Tear Drop Horse Hair Pot

Horse Hair Decorated

This sig’ recipe is for all of us non-technophiles and first timers.

1)  Relax, and crack open a cold beer.
2)  Pour 3 1/2 gallons of water into a bucket.
3)  Stir in a tablespoon of sodium silicate and/or soda ash.
4)  Mix in 17 lbs of XX saggar or 9 lbs. OM 4 ball clay* and put the bucket up on a table.
5)  Finish your cold one and wait a day (20 hours).  This time factor (20 to 24 hours)  is very important.  If you wait any longer all the particles will settle to the bottom and you won’t have workable terra sig.
6)  Siphon off the top 1 gallon.**  (This includes the little bit of water off the top)  This top 1 gallon is your terra sig.  You can use immediately or store it for several years. Dump the rest.  It’s just dirt!  “Release it back into the wild.”
7) If you want, you can sieve it to get the little specks and cat/dog hair out. (200 mesh –or as fine of sieve as you can lay your hands on.)

That’s it.   Dip it, spray it, brush it.

* OM4 ball clay seems to produce a foamy mess on the top but don’t worry about it.
**If the finished 1 gallon of sig isn’t fine enough for some ungodly reason, then stir just that 1 gallon up again, and let it sit for a couple of hours to let the big stuff settle out. Then pour the thin liquid off the top and throw away the bottom 1/2 inch.

Terra Sig–Application and Polishing

Apply terra sigillata to bone dry clay.
Use only enough sig to bring up nice satin shine.  Caution, more than 3 painted layers of sig may start to crack and peel off in later firing processes.  Do not stone burnish a pot before applying the terra sig or it will flake off in the various firings.

Brushing
Put the pot on a banding wheel.  Coat a soft glazing brush with sig.  Spin the pot and apply an even coat onto the pot as it spins.  Buff the pot.  Repeat if necessary.

Dipping
Pots can be dipped into the terra sigillata and then allowed to absorb before polishing.  The dipping process is repeated with enough time allowed for water absorption.

Spraying
Sometimes the terra sigillata is sprayed onto the pots using a Paasche “H” airbrush with a #3 or #5 tip.  The pot is placed on a banding wheel and several coats are sprayed on taking care not to cause runs.  The pot is then buffed and the process is repeated until the desired level of shine is achieved.  (Usually 2 or 3 times).  A regular glaze sprayer can also be used successfully.

Polishing and Buffing
Before all color of water has been absorbed, buff/polish the sigillata surface with soft tee-shirt cloth, pantyhose or soft plastic. Take care to apply only enough pressure to bring up a shine but not to remove the terra sigillata. Metal/stone burnishing objects can be used but are not recommended.

03 Sep 2009 VC Blue Green variation: cone 6-10
 |  Category: Glazes and Slips, Recipes  | Tags: , , , , , ,  | Comments off

This is the glaze I used as a liner in some salt fired pieces.  It’s a beautiful glaze which makes a great liner with pleanty of subtle interest.   It does run quite a lot; I’d suggest making certain the bottom of the put does not have a very thick coat as the glaze will run down the sides into the bottom and may cause bubbling or cracking.

40  Neph Sy

10  EPK

14  Flint

10  Gerstly B

8  Lithium

8   Whiting

10  Zircopax

1.4 Copper Carb