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Member Since 06 Apr 2010
Offline Last Active Today, 11:33 AM

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In Topic: How Much Do You Stay Within Glaze Limits?

Today, 11:30 AM

It all depends on that for which you are looking.


The most "interesting" glaze surfaces typically are those that come from some so-called 'imbalance' in the oxide distribution in the melt, most often causing some chemical unevenness in that melt, the lack of full melting of some raw material component, or the precipitation of some silicate type materials onto the surface in the cooling phase.  Or all of the above.  Or takes advantage of a raw material source for oxides that casues a 'defect' as the glaze is melting ... that we look at as "nice" (ie. American Shino crawling). 


Keep in mind the "limits" that everyone talks about are for what might be defined as "good glass".  And that "good glass" is defined by relatively modern industrial standards. The criteria has as much to do with stability, REALLY long term durability, and consistency as it does with any aesthetic qualities.  THOSE are criteria for mode rn industry.  (There is a reason that bathtub and toilet and sink glazes look like they do.)


If you are not concerned about the same things...... then the "limits" can apply less and less to what you are doing.


If you are making food service wares....... then concepts like the leaching of potentially toxic materials likely should be in your list of desired criteria. 


If you are making sculptures for outdoor installations, then stuff like durability in acid rain and pigeon poop likely should be in your list of desired criteria. 


If you are making floor tile, then hardness and resistacne to abrasion likely should be in your list of desired criteria.


Understanding how the various limit formulas might help you evaluate your list of personal criteria is where the art of USING glaze chermistry software comes in. 


Only you can decide what those criteria are. 


The only formal "laws" relative to the production of ceramics in the USA at the moment are from the FDA and the State of California... and they pertain to any wares that contain lead or cadmium compounds.  Not hing else is formually regulated.  You also DO have what are known as standards from organizations like ASTM for the labels of things like "microwave safe" and "dishwasher safe".  Of course general liability law says if something you make harms someone... you can be held liable in either civil or even potentially criminal (unlikely) situations.


Then there is a piece that is the "moral" dilema.  If you make wares that are somehow "sub-standard" in some way....... and you know that they are....... what do you do with them?  For example, if you have a dinnerware glaze that is drop dead gorgeous........ has NO toxic components...... but it is outside limits.... and the way it is outsisde those limits tells you that compared to a piece of commercial Noritake dinnerware....... the surface will not stand up to repeated washings as well......... what do you do?


NO easy answers.


Anyone who uses American Shino and sells it is "outside limits".  (Guilty!)  Anyone who woodfires and sells work with natural fly ash deposits is "outside limits".  (Guilty!)





In Topic: It Is Potters Council Advisory Board Election Nominations Time Again.

19 November 2014 - 07:55 PM



The deadline never was "reduced"..... so it was not "extended".


My forum posting here was simply a "call to action". A standard advertising approach to get things happening. If you don't ask for action immediately, people procrastinate. Then the deadline passes.. .. .. and things don't happen. Human nature.


This CALL TO ACTION has already resulted in a 100% increase in the nominations from the membership that is not already somehow related to the Board. We got ONE person from the forum throw their own hat into the ring themselves (THANK YOU PROFUSELY!!!!!!). That has not happened in the past TWO election cycles. The past two... the Nominating Commiittee members had to review membership lists and solicit specific people.


THIS is a far better thing for the health of the organization.


Anyone else got ideas???????? Lets make this at least a 200% increase. ;)






PS: Chris, can you please change the @ sign in my email address above to (the AT sign) as I had done above. I don;t want the active hyperlink in a forum like this. Thanks. I could do it as a Mod... but it is more appropriate for me to ask you to do it. :)

In Topic: To Submit Or Not To Submit

18 November 2014 - 10:39 PM

Ceramics Monthly (print and digital) has listings of exhibition calls. Also right here in the CAD Events section.


And sign up for a submission account at JuriedArtServices.com which is one of the places that a lot of shows use to screen digital submissions. And another submission site to sign up for is callforentry.org . Both of those have listings... and also send out calls.





In Topic: The Double Dip

18 November 2014 - 12:45 AM

Nothing particularly new there for anyone who has been "around a while".  Learned this technique about 1967-68 in Ceramics 1.


I use it all the time, but I grasp the foot area, not the foot and lip.  If you design the piece well...... there IS a place to grip the foot for this purpose.


I also sometimes on certain pieces allow the finger marks from gripping the piece to show as "decorations of process".  I also do "yubigaki"..... finger wipes in the wet glazes frequently.





In Topic: What's Your Choice Of Torch?

17 November 2014 - 08:40 AM

A flame type torch and a heat gun do two very different things with the clay.


The heat gun moves a lot of AIR over the surface along with the warming action. This tends to dry the outer layer of the clay, leaving interterior wall more moist.


The torch applies a lot of heat energy to the clay but little air. This dries the wall section more evenly that a heat gun (or blow drier).


I use a torch frequently when I am doing workshops and demos. I prefer the more even drying it causes. I rarely use a heat gun. Almost never a blow drier.


I typically use one of the more expensive "instant on" units from Home Depot or Lowes. In Japan... they have really NICE little torches.... but while I own a number of the torch heads.. .... I can't get the darn propane/butane cans that fit them here in the States.