Sunday, January 23, 2011

The Joy of Metal Clay- Cork Clay

Cork Clay is a mouldable form of cork that can be used to create forms to cover with metal clay.

I use cork clay to help make hollow forms when making syringe forms or if I am making a sculptural piece.

I have spoken about using cork clay with syringe in a previous post about syringe metal clay.

Cork Clay is relatively easy to use. There are a few basic principles to keep in mind:
  1. Mould your shape out of cork.
  2. Make sure you cork is completely dry before you add the metal clay.
  3. Cork clay is dried best using an air dry method this takes longer than 24 hours and is dependent on the size of the cork and the humidity in the environment. Some people use dehydrators or hot plates to speed up the drying but this can more often cause the pieces to distort and crack. Art Clay World suggest the you dry using heat around 200F and suggests to fill cracks with more cork and to sand or file the piece when it is done. Personally I don't worry about sanding and I just shape my clay to the piece.
  4. Once your cork shape is dry you can apply your metal clay.
  5. Dry the piece and fire it. (NOTE: If the piece is covered with solid metal clay - no holes I will put in a small pin hole to allow any air or condensation to escape)

Firing Pieces With Cork - First, torch firing is not recommended with cork clay. I recommend kiln firing with some modifications. A big issues with firing cork clay(or any combustible core) with metal clay is a risk of melting. Sometimes, especially if you have a lot of cork to burn out, the process of burning the cork will suddenly raise the temperature in the kiln about he melting point of your clay. This may cause your piece to MELT!!!! SO, when firing pieces that include cork clay you must accommodate this possibility or you may end up with a melted piece. What I do is: I ramp my kiln to 800F then hold the pieces for 15 minutes (to allow the cork to burn out) then I ramp my kiln to the firing temperature I want (usually 1600F) and hold as long as I want (usually 2 hours). Another important point to remember is that you should have good ventilation (as with all metal clays) when firing cork clay, I know several metal clay artists who are irritated by the fumes from firing the cork.

Primarily I have used cork with silver metal clay. I have to experiment more with other base metal clays. (I will be trying some cork and FAST FIRE BRONZE next week.

Other NOTES:

FAST FIRE BRONZE CLAY is available for in store purchases at BeadFX at this time. (sorry not online yet)

Also, Metal Clay Play Day next Sunday, January 30, 2011, 11 a.m. - 5:00 p.m. at BeadFX - I will be filling in for Jennifer Tought and I plan on playing with the FAST FIRE BRONZE. It you are in the area come join us (it is best to call the store 416-701-1373 to register in advance to ensure space...or drop ins are welcome if there is room - $10 + HST)

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