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Member Since 06 Apr 2010
Online Last Active Today, 07:57 PM

#56646 Glaze Not Uniformly Glossy On Cone 04 Body

Posted by JBaymore on 14 April 2014 - 09:21 PM

"Ceramic Science for the Potter" is an absolutely GREAT book.... but not a "starter" book.  Too much information in the wrong format.  It assumes some decent knowledge.  As I remember ,... it is also expensive on the used market (not sure).


The best 'starter stuff' is getting Insight Level II and the nice little "Magic of Fire" book that comes with it and the access to the secure info on Digitalfire.com.  Then work thru the tutorials in order... and follow the other stuff in Magic of Fire.  I now use that as the "text" for my Ceramic Materials I course at the college...and have for a few years.


"Clay and Glazes for the Potter" (Robin Hoppoer revised edition is best now) is a good first book .... but the price is crazy now.





#56644 Need A Clear Satin Glaze That's Not Cloudy

Posted by JBaymore on 14 April 2014 - 09:15 PM

Title typo fixed :)

#56630 The Dangers Of Advice Without Experience

Posted by JBaymore on 14 April 2014 - 05:45 PM

As I've said an awful lot on the forums here.......... vet your sources.






PS:  Just becasue 'everyone is saying it' doesn't make it necessarily true.

#56457 Cone 6 Body Or Cone 6-10 Body: Much Difference?

Posted by JBaymore on 10 April 2014 - 03:28 PM

There is no such trhing as a cone 6 to 10 body.  Can't be due to basic ceramic chemistry issues.


It is one of three things:


1.)  Overfired at cone 6 and mature at cone 10.


2.)  Mature at cone 6 and overfired at at cone 10.


3.  Underfired at cone 6, mature at cone 8, and overfired at cone 10.


CAN'T work too much different than that above scenario I described.  Likely it is really a cone 8 body if the manufacturer is smart.  Then is is only "slightly screwed up" at the typical cone 6 and cone 10 that most folks fire.


This is the manufacturers keeping their clay body inventory needs in check.  They trade off the problem to the end user.  Caveat emptor.





#56315 Crazing On Mugs Only!

Posted by JBaymore on 08 April 2014 - 11:48 AM

OK>.. now I'm confused........... you said



I have been using the same clay,slip and glazes purchased from a local ceramic shop. Everything has turned out beautifully but I got a new mug mold that will NOT stop giving me issues!


Then you said.........



My crazing is OVER!!!!! I went back to using my local slip and it worked!! My pieces are perfectly craze free : ) Thank you everyone for the advice!!


If you had said you changed the BODY you were using along with the mold.... we could have gotten to the answer without all the confusion.  Then all the changes in which glaze used was just a "red herring" dragged across the path.


We could have saved you a lot of time.  Sorry.





#56283 My Wheel.

Posted by JBaymore on 08 April 2014 - 08:08 AM

Looks a lot like a Korean Onngi wheel...... except made from steel not wood. Nice .





#56225 I Know This Has Been Asked Before, But Maybe More Specific Answers? - Shows

Posted by JBaymore on 07 April 2014 - 08:56 AM

One of the "milestones" in really developing as a "selling" artist is getting a decent amount of backstock ahead.  So that at any given time you are not making for the next coming show / opportunity......... but are well ahead of that curve.  This of course requires the ability to invest the money in materials and time necessary to get that work accumulated... and also the storage area to backstock the pieces.


So rather than think about precisely how much to get together for those 2 shows... just start producing (today! ;)) as much as you can between now and then.  And keep producing even if you think you have "enough".  Get ahead of the demand... and try to stay there.


Then when you get an opportunity... you can jump on it....... instead of worrying about producing new work for the show / sale / client / etc. .





#56167 Expectation And Appearance

Posted by JBaymore on 06 April 2014 - 05:20 PM

As an artist... it is always safe to dress in all black too. ;)





#56151 Expectation And Appearance

Posted by JBaymore on 06 April 2014 - 11:32 AM

The customer is always right, but often wrong.

People comment that I don't look like a potter ... what should I change to fit their vision?
I'm already wearing jeans and a t shirt ... Maybe it's the shoes?



Yiour choices are tie-dye T-shirts and dreads, a checkered wool shirt and Carharts, or tattoos and piercings. Pick one. ;)





#56078 Clay Body Or Glaze Fit Problem - Shattering Cups

Posted by JBaymore on 04 April 2014 - 12:36 PM

Cristobalite forms in a body with insufficient fluxes present to act on all the silica at temps above 1200 C (2012F).  Not likely the culprit in a body that has so much in the way of fluxes...and firing to only 04.  But it is impossibe to know for sure what the chemical balance of the body is without an analysis of the particular cullet she is using.


Generally speaking "cullet" is typically a variable composition material....... unless your supplier has a specific analysis for the batches you are getting.  So from batch to batch.... that composition might be varying a lot.  Frits on the other hand are generally stable compositions.  Personally... unless I bought HUGE stable batches in advance... I wouldn't use it for a clay body.  Asking for variation issues in production.


As to Insight........ when you BUY the Level II version of Insight (well worth the access to the secure portion of the Digitalfire site) it has the ability to add in materials data for the MDT from around the world... just one of the reasons that I like it...  I'm frequently converting from American to Japanese and Japanese to American recipes.


If the glazes are pinging.. the COE of the glaze and the COE of the body don't match.  Remember you can't use the COE figures from ANY glaze calculation program for the BODY COE number.  It can't be calculated by any method known yet... it must be physically measured (dilatometer ... or the "known expansion glaze" method of approximation).  Calculation programs are of limited use in body development..... it is still unfortunately a much more empirical "testing based" approach....even for industry.  (They just have nicer "toys" to use when doing it -tools-.)


There are differences between "virterous" as we think of it traditionally for a body and "melted" as in potentially overrfired.  Generally you want an apparent poroisty approching zero in a vitreous type body....... but after you go past that mimum on the plot curve of porosity...... you will start having such issues as you are experiencing.


There is a quality of glasses (and vitrified bodies) that is called "brittleness".  That can be a significant factor here when combined wit hthe seriously crazing glaze.


To see this level of issue you likely have TWO issues synergistically combining.  A poor strength body and a non-fitting glaze.  I'd fix the body issue first and then work on the glaze issue.  Do one at a time (basic scientific method).  In fixing the body you MIGHT end up inadvertantly fixing the glaze.





#55989 Looking For Other Potters With A1-At Deficiency

Posted by JBaymore on 03 April 2014 - 08:49 AM



Hummmmmmm........... I'm gonna' come at this question from a very different "place".  Probably not in the "popular choice" department. 


First of all.... sorry you are going through this.


Starting things off here with a bit of a "source vetting" statement.  Part of my formal job at the college is to teach about ceramic toxicology, for many years I was the chair of the Health and Safety Committee of the school, and for one year I was the acting Intitim Health and Safety "officer" (sole responsibility H+S issues) for the college.  (However I am not a medical professional.) 


The place to figure this important question out is not on an internet forum frequented by ceramic artists, no matter how good everyone's intentions might be.  It very much sounds like you are talking about a significant potential risk to your health and length of life.  This discussion should be taking place in great detail with your doctors.  God love potters... we all want to help each other.... but this is a medical issue, not a ceramic issue.  You  want to fix kilns or glazes... talk to experienced potters.  You want to deal with medical issues..... talk with experienced doctors.


Your physicians need to know precisely what you are working with as far as potential exposures go.  In writing, and in as much detail as you can give them.  That way they can make educated recommendations for you.  You can also always go AMA (against medical advice) but that is your personal decision to make after getting as accurate advicce as you can obtain.


If your intent/desire is to continue with clay work seriously, then you should be seeing an occupational health specalist in addition to your G.P. physician (get a referral).  Those specialists will know how to interpret the information that you will give about potential studio exposures and such.  And the effectiveness of potential "controls" that can be put in place to mitigate any such exposures.  Most GPs don't tend to believe that we handle or are exposed to the nasty stuff that we are..... which can cause them to not believe that there is as much hazard as theere might be.... or to over-react the other way and over=blow the issue.  Occuaptional health specialists deal with industrial exposures........ and understand the issues.


As far as studio exposures go, you can get precise numbers to give you physicians that will help them quantify the issues or non-issues.  Your main issues in this case appear to be airborne toxins and irritants.  You can get air sampling done relatively inexpensively (few hundred dollars) that will give your doctors very accuratte information to go on.  An occupational health specialist can give you a local recommendation for a engineering controls company that can come test your workspace for you.  Lots of ways that this can be done... but one useful approach likely would be to have you wear a little filtering pickup device as you spend a full day working as you typically do.... and from that they can tell pretty precisely both qualitatively and quantitatively what the risks are.  From there...... other tests can get doine, as needed.


The "good news" in this is that while we all should be concerned about the exposures we get to stuff in the studio, usually the exposures are at well lower levels than what we all tend to all fear.  So it might very well be that your doctors can say that yes, you can continue to work in the studio with appropriate care.  But to have them recommend accurately, they need to know pretty accurately what doing that might mean to you.


If you PM me your email address I wil send you a "handout" that I use in classes at the college that might be useful to hand off to your physicians for "reference".


Best of luck with getting this sorted out.





#55947 Election Results-Drumroll ++++++And The Winners Are?

Posted by JBaymore on 02 April 2014 - 10:42 AM

clay that is 98% lighter in the pug form


I'm working on this.  Instead of a de-airing pugmill, I am developing a helium impregnating pugmill.  Details to follow.  ;)





#55889 Top Ten Myths About Creativity

Posted by JBaymore on 01 April 2014 - 09:16 AM

Oh I like it! Wait until the Feds get a hold of this one and throw us into a higher tax bracket! :wacko:


OOPS!!!!    I play with clay. :D





#55868 Top Ten Myths About Creativity

Posted by JBaymore on 31 March 2014 - 09:16 PM

Maybe we should adopt that same phraseology for what we do.  They are accurately communicating what they do.  Medicine is considered an art, not a science.  There is more to doing it well than simply pure science.  Ceramics has a "technical, scienc-ey" side too.... but it also has more to it than the pure technical. 


So...... we practice ceramic art.  Most of us are GPs.... General Practitioners of Ceramic Arts.  (New initials after name.... G.P. C. A.) ;)




.................john; G.P.C.A.

#55767 An Apology

Posted by JBaymore on 30 March 2014 - 12:30 PM

Thank you, TJR, well spoken and accepted.  I do share the 'ouch' of the grammar and spelling blips.


As do I.  As a college professor....... it is difficult to "sit on my hands" on this.


Tom... the formal public apology was a testament to "who you are".  Kudos.