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Member Since 06 Apr 2010
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#98451 Wishing Everyone A Happy And Healthy 2016.

Posted by JBaymore on 31 December 2015 - 03:55 PM

Wanted to say "Happy New Year" to everyone as we shortly usher in 2016.





#98422 Goals For 2016

Posted by JBaymore on 31 December 2015 - 11:39 AM

Still be around for 2017.  ;)





#98295 Calcium Borate

Posted by JBaymore on 29 December 2015 - 03:07 PM

.......... i.e. the temperature is held long enough for an equilibrium state to form, which is seldom the case when firing a kiln unless you have an unusually long soak time. .........


This is a key issue that many folks miss when looking at results and how they often do not match "theoretical" expectations.



Also..... great comments on heatwork there above you gave, Tim.  There was a great presentation that was at NCECA a few years ago... by engineers and manufacturers that were working on changing the models that computerized controllers use to model "heatwork".  It was fascinating.  A lot of stuff I knew....... but "packaged" in a different way.  Chris Campbell and I sat together for that one.  


I was kind of amazed at how FEW people were in the room listening.  It is a core aspect of executing our craft.





#98274 Proper Hand Position For Wheel Throwing?

Posted by JBaymore on 29 December 2015 - 10:33 AM


It isn't so much about pressure. Pulling (or lifting as I have started to prefer) is about thinning the wall and moving the clay upward. There is very little pressure applied when done correctly.



The term "compression" is a poor term to use for what we tend to do in a lot of our clay processes.  Because it does tend to imply "pressure" in most people's minds.  While we align clay platelets (at least a bit), there is very little to "compress" our of the wet clay.


Maybe think about it a bit as if you were creating an extruder die.  The spinning wheel is supplying the force of the plunger....... you are 'extruding' the plastic clay upward through the space that your fingers create for it to flow thru.  It is a "moving extruder".






PS:  Giselle........ PM me your email address.  It is intended for low intermediate and up throwers... but some thoughts might be useful for you.

#98167 Who Is Attending Nceca This Year? (Spring 2016)

Posted by JBaymore on 28 December 2015 - 11:04 AM

 Hoping more potters fit in a lecture hall than last year in Providence.


It is SO hard for the NCECA folks to out-guess the attendance at the various offerings.  (Without going to a pre-registration system... which would be a nightmare!)


At the "teabowl" lecture I did at the Providence NCECA, I had people standing along the back and in the doorway. Who could have guessed that (in America) 800+ people cared enough about the hair-splitting differences between generic "teabowls" and Chawan for actual Tea Ceremony????  I know it surprised me at the level of attendance.


I've been in other presentations that I thought, because of the topic, would have lots of people, and the 750 seat halls had maybne 100 people in it.


I don't think there is a way to solve that issue that works.  Other than if a particular presentation is really important to someone.... show up very early.





#98066 Metallic Taste To Glaze

Posted by JBaymore on 26 December 2015 - 09:23 PM

I'd say if the glaze is giving you an obvious  'metallic taste'... that is a big "red flag" right there.


Note that suppliers of commercial glazes will not indemnify the user of their products.  They will not defend you in the case of a product liability suit for what you make with their products.  In fact they will almost 100% for certain work hard to defend themselves from the potter. That means that it is the potter's responsibility as a "manufacturer" (yes... you are one) to assess if your products are appropriate to the use you are marketing them to fulfill. Any product literature they might provide is basically 'marketing materials'.  And the info about stuff like "not food safe" are likely mainly to help protect themselves from potential issues...... not to protect you.


Also note that the ASTM non-Toxic label on many art supplies products is based on the hazard to the user of that product, not the buyer of products produced USING those products, and speaks only to the hazard in the state that the materials are supplied (as in wet clay, .... not dry clay).


This following is a little "techy"... but it comes from THE 'horses mouth' of glaze gurus at the moment, William Carty, from Alfred's ceramic engineering school.  (He and Michael Katz (also Alfred) will be lecturing at NCECA in Kansas City this coming spring.)  It was Carty's lecture at a past NCECA conference, and was sparked by the information (and mis-information) circulating in the studio ceramic community about glaze safety and leaching and the like.  Obviously to get everything out of it... you had to be there (I was).  But there is good info still to be had from his slides. 




Hope it is useful for those reading the thread that are concerned about the various "food safe" issues.





#97909 Who Is Attending Nceca This Year? (Spring 2016)

Posted by JBaymore on 24 December 2015 - 11:02 AM

By request, I have "pinned" this topic to the top of the forum section so that it will remain there until NCECA happens.  I also added a date to the title line to make sure it is not confusing.





#97833 Who Is Attending Nceca This Year? (Spring 2016)

Posted by JBaymore on 23 December 2015 - 10:22 AM



Both Michael Katz and (in particular) William Carty will be presenters at this NCECA conference.  I would venture to guess that those will be sessions that you would be VERY interested in.





#97753 Qotw: Would You Ever Completely Retire From Doing Your Art Work?

Posted by JBaymore on 22 December 2015 - 11:59 AM

No.  (Unless it was "physical" of "mental" disability, of course.)  Scale will just change.





#97578 Nice Christmas Gift

Posted by JBaymore on 19 December 2015 - 07:44 PM

It is nice to know there are still honest people out there.  :)





#97297 Are There Glazes Designed To Be Mixed Into Clay To Give It A Color?

Posted by JBaymore on 14 December 2015 - 10:19 AM

Hi and welcome to CAD forums.


Search the forums (from the main forum menu screen) for the topics "colored clay", "colored porcelain", "neriage", and "nerikomi".  This is a commonly discussed subject.


The usual colorants are commercial body stains.  Stable colors, and a bit less toxic than using raw "colorants".


Search "Mason Color and Chemical" glaze and body stains for one potential commercial source.  Most ceramic supply places sell these colorants.





#97254 Glaze Runs Good Kind Not Bad

Posted by JBaymore on 13 December 2015 - 08:55 AM

After you have applied the glaze (in general) to the top part of the form, go back using a small brush to really thicken up the glaze layer at the bottom area of the end of the previously applied glaze in the spots that you want the runs to happen. 


Also "break" the linear ending line of the glaze layer slightly downward (couple of mm will work) in the spot the run should happen with a bit of the glaze.


"Happy accidents" are not always accidents. ;)


EDIT:  See here at bottom of form... those are not "happenstance": gallery_1543_134_4274355.jpg





#97226 Another Pinging Question

Posted by JBaymore on 12 December 2015 - 12:21 PM

If a clay and body combo is very close to a fit (well matched COEs) but not actually "there", almost any variation in things can cause the existing mismatch to start to show up.  Stuff like thicker glaze layer, faster cooling, slightly different finish firing profile, poor oxidation of organics in bisque firing, variations in wall thickness profile, and so on.


If this is the case, it possibly also means that the glaze will exhibit delayed crazing in use over time.... even if you are not seeing it when you unload the kiln and send work off to its intended destinations.


Make a test cup.  When the glazed work comes out of the kiln, paint the surface with india ink.  Let it sit for a couple minutes, and then wipe it off the surface well.  Look for crazing lines getting stained in.  Take the same test piece, and put it in your freezer.  Leave it there for a few hours.  Immediately fill it with hot tap water .  Repeat the india ink test.  Repeat this sequence a number of times.  That will tell you a lot about the actual "fit" of the glaze to the body.





#97107 How Do You Do Custom Orders?

Posted by JBaymore on 10 December 2015 - 11:24 AM

Been there, done that, bought the T-shirt.  Now prefer the "just say no" approach myself. 


When you work on figuring out the price, put in a lot of effort.  Consider every possible scenario.  Then when you have the final price..........




Then tell the client.


You'll still end up getting way underpaid for your time.






"The color is slightly off what I thought it would be.  Can you do that again and get the shade of blue just a little lighter....... like my drapes?"

#96853 The Great Pottery Throw Down

Posted by JBaymore on 06 December 2015 - 11:31 AM

GiselleNo5 said :


I hate elimination challenges because what if somebody is just having a bad day! Or week! What if their cat died or they have a cold? I think that knowing they can be eliminated puts so much pressure on and not everybody performs well under pressure. Some people panic and their brain shuts off and they make stupid decisions or can't think clearly.


These "reality" type shows are about creating that kind of situation deliberately.  Watching people "self destruct" makes so-called "good TV".