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Surubee

Member Since 30 Jan 2012
Offline Last Active Aug 17 2016 01:33 PM
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Posts I've Made

In Topic: Help! I Can't Center Anymore!

02 August 2016 - 12:28 AM

Hello and welcome JimO.

 

I had a few thoughts about this. Have you checked to see that your wheel is still level? I used to have a kick wheel but gave it up many years ago and switched to electric. If something was not level or became misaligned, it was difficult to center and keep the pots even. Have you moved the wheel recently or could the wheel shaft have somehow gotten bent? Maybe there is a screw or bolt that has gotten loose or worn out. If so, just the act of kicking the wheel could be enough to cause a little wobble to throw things off center.

 

I hope that your issues are just some easily fixed mechanical ones with the wheel and not complicated physical problems with your body.

Best of luck to you with this.

 

Susan


In Topic: Firing A Bowl Upside Down?

30 May 2016 - 10:57 PM

I think I remember hearing an archaeologist once explain that the pointed bottoms of some amphorae and jars were made so they could be easily buried in sand to help keep the contents cooler in desert climates.


In Topic: Raku - Cooling Dunts

07 April 2016 - 10:54 AM

How much difference in thickness is there between the rim and the bottom of the pot? If the rim is fairly thin and the bottom is thick, it could be retaining more heat and the thermal differences could cause the cracking. I cannot tell from the pictures - have you trimmed out part of the foot? If you have not tried it, that might help equalize the temperature variation as well.

 

I also agree with those saying to try a different clay body, or add some sand.

 

Good luck!

 

Susan


In Topic: Wood Duck Mug Wip

09 December 2015 - 11:05 AM

Beautiful work. Glad you are feeling better.


In Topic: Black Clay

19 November 2015 - 11:50 AM

Black clay that you find naturally is often black because of organic matter which will burn out when fired. The color could change to something brown or red after firing. One way you can test it is by making little cones and pinch pots which you fire first to bisque temperature, and then higher if it survives. You can also make a clay ruler to test for shrinkage and another piece to test the amount of water it absorbs after firing so you will know if it is vitrified.

 

To protect your shelves, make sure to fire the test pieces on a piece of scrap shelf or a pad of bisqued clay with raised sides. I have seen tests of these natural clays that have totally melted at high fire temperatures, but are great at lower temperatures. If it has a low melting temperature but a nice color when fired, you may be able to use it as a base for a slip or glaze.