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High Bridge Pottery

Member Since 19 Feb 2013
Offline Last Active Yesterday, 09:34 PM

#91975 Qotw: Do You Strictly Observe The Safety Rules In Studio?

Posted by High Bridge Pottery on Yesterday, 03:44 PM

I would have thought a quick look at the budget for all courses would put ceramics into the firing line when everybody is short of money.

#91942 Will Cromartie Kiln Fire To Stoneware?

Posted by High Bridge Pottery on 03 September 2015 - 04:49 PM

Not sure how the meter does it but I am sure there is some voltage involved from the batteries to work out resistance. No need to have it plugged in and ON when testing out volts and your fingers far away from the metal ends.


You can get bogus reading sometimes, I was told it's a good idea to disconnect the neutral from the element if it is telling you something that seems way off.


You can test to see how far the elements resistance is away from brand new, just need to know what the brand new element resistance should be.

#91931 Will Cromartie Kiln Fire To Stoneware?

Posted by High Bridge Pottery on 03 September 2015 - 01:13 PM

The elements in my kiln have a total resistance of 18 ohm so at 230-240 volts that gives me the 12-13 amps for the plug socket.


In theory it is VA for kw/h so 230 x 13 = 2.9-3.1 kw/h


Celia, I don't actually know the temperature the kiln gets to, never stuck a thermocouple in. All I have are the cones. I would like to go a little slower but the only switch for the kiln is at the plug socket. I would be interested to know the resistance on your elements and see if they match. Mine looked hardly used when I bought it.

I have only fired the kiln 4-5 times, nothing like the 4 years use so it could slow down. The biggest problem are the lids made out of fiber. Mine is so rusted but I think it sat out in the rain for a good while. I have seen many go through ebay with rusted lids so I think it has a few ventilation problems anyway.


Bought it for the idea to experiment with electric reduction but still haven't made it round to that yet :D For £67 I couldn't help myself. 


I am maybe a little hard on the kiln but it can definitely get 1260 or a good cone 9

#91879 Will Cromartie Kiln Fire To Stoneware?

Posted by High Bridge Pottery on 02 September 2015 - 01:04 PM

I have a very old rusty one exactly like that or an even older model. Had to gut all the electrics except the elements as they didn't work and I only have full power or no power but gets cone 9-10 happily in 6-7 hours. Definitely worth it for the right price as you get space for 12ish mugs, size depending.


Found a picture of some pots and the cones from I think a 6.5 hour firing. Maybe 7. Cone 10 is most of the way there. 9 and 8 very flat.



#91823 Qotw: What Do You Think Of Art Critique?

Posted by High Bridge Pottery on 01 September 2015 - 04:52 PM

Most of the hot air from fine art critics barely even inflates my balloon.


I have a hard time defining what art is as it seems to be in everything.

#91380 Qotw: Do You Strictly Observe The Safety Rules In Studio?

Posted by High Bridge Pottery on 25 August 2015 - 01:23 PM

I can't say I really follow them that strictly. I feel there is a lot more in modern life that is killing me quicker, especially my smoking habit, probably all the nuclear waste in the ocean and whatever crap we pollute the air with.


All in all my studio feels quite safe with its small amount of airborne silica.

#91261 I Love This Forum! Throwing Clay Question (Noob)

Posted by High Bridge Pottery on 22 August 2015 - 05:18 AM

I remembered an interesting post by John about different porcelains. That could be why some clays you see look very different. I always find the porcelain I buy really tough, stoneware with a bit of grog is a much easier and forgiving clay to throw with.

"True" porcelain is a composition of just a kaolin and a single ground rock  - called p'tunse.  It is a high silica content feldspathic based rock.  Often also called "Porcelain Stone"   磁器石 )  Neil's basic "recipe" above would approximate a true porcelain (no ball clay) ....in basic chemical composition. Not particle size or distribution.


Might be a "Lost in Translation" moment.  ;)  


In Japan clay bodies are almost always wet blunged with a great excess of water from far less pure materials, through repeated smaller mesh screenings as it is moved to different blunging batches, and then is filter pressed to remove the last excess water.  This process produces really good quality clay out of materials that we would think of as "inferior" or "primitive" by our industrially refined standards. 


In America we tend to mix clay direct to the plastic state from industrially beneficiated (dried and airfloated, etc) clays with just enough water to make it workable.  This is NOT the way to make really good clay.  It is the way to make cheap (production-wise) clay. 


If we took the same kaolin and ground rock the Japanese (and Chinese) use for porcelain, and mixed up a body the way US suppliers typically do.... it'd likely be totally un-useable for forming.


The reason this labor and machinery intensive process  'works' in Japan is that the valuation for ceramic work is generally higher there.  And they are willing to have material cost a higher percentage of the sale price (indicating respect for good starting materials). Many ceramic centers mix up their own clays from mostly local materials (hence the visual distinction between pottery "villages" work).  Clay prices from suppliers in Japan in many/most places would shock you.  In America... many, many potters will go to another supplier if the price of a pound of clay is even one cent more.  No incentive in most cases for our suppliers to make better clay.


If that clay you got to feel was brought from Japan, Chris, it likely was produced by the blunging and the wet filter press method.  That is likely a portion of the buttery quality you mention.  And the repeated screening and settling process will take out the large particles so that is another part.


PS:  For porcelain (in Japanese "Jiki"   磁器  -gee key-), often in the blunging there is a huge magnet suspended in the tank with the mixing slurry... to take out the hematite (iron) nodlues.






#91159 Community Challenge #3

Posted by High Bridge Pottery on 20 August 2015 - 12:52 PM

Yes any technique is fine for this one :D The challenges are probably going to oscillate between something quite open with little constrains to something much more specific. Always open to more ideas.


Loving the idea of the chopstick boxes Misfit. The lid style reminds me a lot of those bamboo steamers.

#90492 Bisque Blowouts

Posted by High Bridge Pottery on 09 August 2015 - 05:30 AM

Was there anything different about your work that survived and stuff that didn't? 


I agree about the firing possibly being too fast. Even though the work is dry there is still water in there. Going too quick through water turning to steam will turn your pots to rubble. Stay around for the first hour or so and you should hear it pop. I am surprised nobody has before.


Could be something else but that is the best place to start.

#90258 Home Made Kiln Controller

Posted by High Bridge Pottery on 04 August 2015 - 09:08 PM

Thank you :D sure I will have some badly written code for you to look over in the future. 


Going to have a lot of hardware issues before that and general electronic design to learn. First stop is a blinking LED. hopefully it will have been delivered tomorrow so I can pick it up and start messing around. The kit really isn't that expensive and is seems lots of companies are now making boards that can do anything with these new microprocessors or computers really, whatever brand you go for.

#90217 Home Made Kiln Controller

Posted by High Bridge Pottery on 04 August 2015 - 12:40 PM

Adafruit only sell the type K thermocouple as that is what people want. If you search for the chip number MAX31855 you can find all the type chips. The only thread I could find on the forum about this is here https://forums.adafr...=type s#p395238 but they seem to say it will work fine.


Ordered a Pi and the board, you can also seem to get free sample chips from the manufacturer so ordered type s chips. Going to be a steep learning curve.

#90189 Community Challenge #3

Posted by High Bridge Pottery on 03 August 2015 - 08:54 PM



Welcome to the community challenge #3

This is a place where we can challenge ourselves alongside other community members to create ceramic works within the constraints set out in each challenge.
The Challenge
This challenge is to make 'anything but round'
Try to be creative with your research and how you translate that into an idea for your ceramic work. 
The Rules

  • Everybody can enter the challenge, all you need is a registered account on the forum.
  • Work in progress (WIP) images are encouraged. It can help to talk through your research and ideas but please don't spam the topic. Keep the updates informative and succinct.
  • One final entry per community member, images no larger than 1024 pixels wide/high.
  • Attach images to your final entry post along with the text Final Entry - Forum Name
  • This will make sure you are not missed out of the results thread. Also make sure you post your final entry in this thread to be entered into the challenge.
  • The challenge will run quarterly and will be
    • 1st February to 29th April, 
    • 1st May to 30st July, 
    • 1st August to 30st October, 
    • 1st November to 30st January.
  • The results thread will be posted on the last day of the ending month. It will be a collection of all the entries into one post for condensed viewing and some post challenge discussion.

The Rest
Remember you are entering for your own enjoyment and there could be a risk that your work develops into something new and exciting.
Be considerate of others and don't post opinions without good reasons to back them up. We are all here to improve and progress with our ceramics.
Some dates may vary slightly as this is a community run project and it will depend on members having access to the forum.
Have any ideas for a challenge? Post them in the ideas thread http://community.cer...hallenge-ideas/

#90123 Community Challenge #2

Posted by High Bridge Pottery on 03 August 2015 - 09:33 AM

are all of you working with something other than google chrome?  i cannot find anything you are discussing though i think i found a tree.

I use chrome, The small,medium and large options can only be found when you are in the gallery and right click on the image you are viewing.


You can either click the thumbnail,small,medium or large and drag+drop into your post that Giselle found out or click direct link (it will open a new webpage) copy the url from the top. It will end in .jpg or whatever image file format it is. Click the tree and past the url into the box that pops up.


They both do the same thing except you can choose a smaller version it looks like through Giselle drag and drop option. With the linking option you can take image sources from other sites post here without uploading it to CAD. Not all website URL can be linked.


You can see the difference, below is an image attached to the post, very small and you have to click on it to see a bigger version. Linking the image lets you show a bigger version directly in the post so no need to click for the full image, although you still can. This gets round the post attachment size problem so no need to struggle editing size.


Attached File  link.jpg   54.53KB   0 downloads



OMG.  I had to zoom in to 300% on my 19" screen to see it IS a tree.  At 100% it just looks like a green blob on a green background.  I thought with glasses I had pretty good vision, oohh to be young again.....






It is a very small tree :D at least I think it is a tree. Had to hover over it to see the 'image' text pop up before I knew what it did 

#89946 Glaze Chemistry, Is It Really Biology?

Posted by High Bridge Pottery on 01 August 2015 - 05:42 AM

It is amazing to learn about Silicate formation, found this video really interesting thinking about how all our raw materials are formed and why they have the chemistry they do. Furthermore how this bonding structure can influence working properties.


It is funny how close silicon and carbon are and the comparisons I found between the formation of Silicates and my past tuition in organic chemistry at school. It's great to think of the kiln as a small volcano breaking and forming new Alumina/Silicate structures.


Can I now view my pots as simple silicate life forms that are hibernating because it is a little cold? :D


#89945 Community Challenge #2 - Results

Posted by High Bridge Pottery on 01 August 2015 - 04:34 AM

Biglou13 - Not an official entry but a really nice pot :D



ChenowethArts - I decided to include your v1.0