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Stone Spiral

Member Since 06 Mar 2016
Offline Last Active Yesterday, 10:54 PM

Topics I've Started

Wheel Head Leaving Dark Tarnish On Clay

18 May 2017 - 03:27 PM

My wheel appears clean and silver, with no visible tarnish. However, when I pull my clay off the wheel, there is black/dark looking clay or slip where it meets the wheel. It's as though the wheel head is giving off a tarnish or the clay is reacting to the metal.


Will this cause problems when firing?

Is there anything I can do to prevent this?


I know I could throw with bats but I don't currently have any. I will go that route if necessary, but in the meantime, just looking to figure out what this tarnish is and if it's going to cause problems.


Disappointing Glaze Firing - Help?

17 April 2017 - 01:46 AM

I just completed my first glaze load. There were several things that I need some help with - and would love to hear your insight. It was a slow ramp to Cone 6 with a 4 minute hold.

1 - Several pieces cracked.

Three plates, a bowl, and a cup. Why might this happen? How can I avoid this happening in the future?

2 - Some of my glazes did not turn out correctly - at ALL

One was Spectrum Crimson, the other a home made turquoise. The commercial crimson turned out glossy white - with the occasional purple-ish streak. The turquoise turned out a matte white, with an almost chalky quality. The glazes were well mixed and sieved; I'm wondering - is it possible for colour to burn out? For example, the commercial glaze says it's good for Cone 4-6, and I fired to Cone 6. Could this particular glaze possibly need to be fired to Cone 5 only? Other ideas?

3 - Bubbling

A few pieces came out with bubbly glaze - very badly on one piece in particular. It wasn't the same glaze (one was cobalt blue, the other a glossy black). I was told that soaking the load for longer would help avoid this... I also heard that one shouldn't soak too long, as it can cause over firing. What do you think - and how can this be avoided?



4 - Guide Cones
The cone 5 guide cone was completed melted, not just bent over/slumped. The cone 6 guide cone hardly had a wobble in it. Why would cone 5 look SO over-done, while it looks like cone 6 was barely reached?


Thank you so much! I was pretty bummed when I opened the kiln... however, I still consider it a success as I am learning so much. There were several interesting pieces, nothing exploded, nothing stuck to the kiln shelf... (I like to look on the bright side).


Thanks again for your insight!

Ack! Medium Fire Not An Option - Question/help Needed

10 April 2017 - 01:35 AM

I spent the evening carefully loading my kiln. I went to start my Medium Ramp Cone 6 Glaze Fire - and the button for "medium" ramp is sticking/not working! I can only choose slow or fast ramp presets, until I can get it fixed/looked at. In the meantime, I do have to get this firing done as there are time sensitive pieces inside.

I have been doing some research on how that will change the glazes, and I am feeling a bit stuck.

Some people say a fast ramp with hold time and/or slow cooling, will produce nice results.

The Skutt website specifically says fast ramp is only for decals and lusters, and that glazes should only be fired slow or medium ramp.

I am concerned that a slow ramp to cone 6 may use a lot of power/be expensive.

I am concerned that a fast ramp to cone 6 may cause problems in the glaze - or alter it significantly? I would add a 5 minute hold to even out the kiln, and perhaps a slow cool?


This is unfortunate because my kiln is loaded with 100 test tiles (so how I fire this load will probably be how I will want to fire in the future) and also, quite a bit of student work.


I do slow ramp bisque firings. I have only ever glaze fired using Medium Ramp to Cone 6 (the preset)

Changing that feels scary!!





Edited to add: This particular load is mostly commercial glazes. There are some homemade glazes in there, however most of the items have a cone 5/6 Spectrum or Laguna glaze on them. I don't know how the slow or fast ramp will effect these glazes.

Cone 10 Porcelain To Cone 6?

04 April 2017 - 09:00 PM

I have a friend who has a box full of bisqued cone 10 porcelain which she would like me to glaze and fire for her.

I am 100% certain it is cone 10 porcelain, as I was able to connect with the retired potter who created it - so I have it straight from the horse's mouth. I did my due diligence to make sure I knew exactly what it was - and was unwilling to fire it if there was any question.


So, historically, I have not done much cone 10 firing. In my studio I only use cone 5/6 clays and glazes.

I am trying to figure out what pitfalls may occur if I fire cone 10 porcelain to cone 6. I realize the clay will be underfired/immature, but I guess I don't know what that means - apart from fragility?


What else might I run into? Or is this perfectly fine?

I can throw one pot into my next glaze fire and find out, and I'm curious what I might be able to do to have this turn out.

OR - should I save my time and send the box back to my friend?


Wheel Quit Working

31 March 2017 - 03:41 PM

I have a couple of wheels in my studio, all different makes and models so they each have their own way of being maintained/repaired.

My Kemper Clay Devil, the one I use for kid's classes, has decided to quit on me!

I have tried plugging in to different outlets, so I know it's not the power. (Also plugged other things into the same outlet and it works)


The wheel was working fine, and then I did a wet mop of the floor. The pedal got wet, but really... not that much? It's not like it was flooded, and no more than usual when I mop?


Anyways, I am going to take it apart today and see if maybe something got bumped or dislodged or... somehow jumps out as obvious to my non-mechanical brain.

If anyone has any tips or ideas on how to troubleshoot this issue, I would be grateful!

~ R