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#111958 Qotw: Epic Failures Anybody?

Posted by JBaymore on 25 August 2016 - 01:22 PM

A long time ago in a galaxy far, far away..............


I needed more of my custom clay formula mixed up.  Called up my handy-dandy long term supplier and ordered another 2000 pounds of it.  I had a show coming, a number of custom orders to complete, store/gallery stock to replenish, and so on.  I had already started production on the noborigama load a bit... but knew I'd be running out of clay any day. On the average I know that my wood kiln takes about 2000-2200 pounds of clay made into pots for a load....depending on the particular types of pieces for that load.


The clay arrives one day.  As the driver is unloading it I notice that the bags are labeled "Bateman" not "Baymore".  I ask the driver about that.  He says...... "Not to worry... just mis-labeled".  I say.,.... please call the factory and check on this to make sure it is my clay.  He does.  Gets assurances that it was just a mis-spelling of my name when the warehouse guy heard it and labeled the bags.  OK....... fine.


I continue working on the load.  At one point I am wedging together some of my OLD clay.. and some of the new clay.  As I slice the bung, I notice a SLIGHT marbeling of the clay.  Hummmmmm.............   Now I know enough about clay bodies that organics in the clays can cause slight color differences that have no bearing on the fired results.  That is normal.  Things like fireclays and ball clays (both were in that body) often look different run-of-mine to run-of-mine. 


BUT.... I flash back to "Bateman".  I call the supplier again myself.  Yup... it is the correct clay.  Yup... it's organics.  Yup...... not to worry.


Finished making and bisque firing the load and glazing.  Stacked the kiln.  Fired the kiln.


Unloaded the whole load into the shard pit.


I was NOT my clay formulation.  Probably was a cone 6 oxidation body.  Or a really botched mixing job with materials mis-weighed.  Just about nothing was salvageable in the whole load.  Looked terrible, slumping, warping, cracking, awful color... you name it... it had it.


This nearly bankrupted me.  Each firing of a large kiln like mine is a huge investment of materials and labor TIME.  LOTS of eggs in one basket.  Amongst the other stuff, I had one huge 12 place dinnerware set order in there for a very good client that was to be a wedding present..... missed the deadline.  Lost the purchase and the client.  Had no stock for general sales for a while.  Had used up a lot of paid-for materials.  Got zero dollars for my investment of all that time (time which simply can't be recreated).  Needed to spend more $ to get more materials to make more work.  Put production behind by one full kiln work cycle. 




SO....... I went to small claims court to try to recover something out of this mess.  Now the law says that I had to go to the court in the place where the company was located.  That was a couple hours drive away. I also consulted with a lawyer.  So there was more time and money invested.  My day in court finally arrived (weeks and weeks after he unloading).


And....................... I lost.


You know those disclaimers that the suppliers have on their websites and in their catalogs?  The ones that say "we are not responsible.... clay and glaze materials are naturally occurring minerals and we have no control over .... blah....blah.... blah".  Yup.... they are very powerful tools in a court of law.  They stand up.  Not only did I lose the value of the load... I had to pay for the clay!  Now the court DID allow me to not pay the INTEREST on the clay cost bill that accrued during the dispute.  Yay!


Lessons..... a multitude. 


The BIG one........... the phrase I use on this forum and in my classes all the time......... "test, test, test".


Do not put materials into full production until you KNOW that they are working correctly.


Also... trust you gut.  That should have lead me to .....test, test, test.  I screwed up.  I didn't.


The company in question... which shall remain nameless....... no longer exists.  They went out of business not all that long after this incident.  Guess maybe they had a lot more incidents like this.


There you have it.  Don't repeat my mistake.





#111949 Supplies To Buy When Buying A First Wheel?

Posted by JBaymore on 25 August 2016 - 09:50 AM

I'd put in my vote for a better wheel also for a totally new beginning thrower. 


If you are not looking to really make throwing a long term high priority in your clay adventures...... look for a used one... or a new Brent B or something like that.  You probably won't need "horsepower" or torque like even a Brent C ..... and you don't need to spend the $ for quiet of a Shimpo Whisper.


Check "The Potters Attic"  on Facebook for used equipment ads.  And Craigslist.  And anything your local Potters Guild / club might have.





#111947 Glaze Calculation Software Recommendations

Posted by JBaymore on 25 August 2016 - 09:28 AM


- include supplier and price details for materials





Insight does that.  Check the MDT options ... there is a place for you to put in the price you pay.  The price per pound for any glaze (if you've done that) is dis[played in the "data" area that shows stuff like Si:Al ratio, Mol wt, and so on.





#111774 Press Molded Tiles/trivets

Posted by JBaymore on 21 August 2016 - 06:31 PM

Have you looked at the pricing for commercial ceramic work in nice department stores?  Made mostly by jigger, jolly,hydraulic dry pressing, slip casting, and injection slip molding.  I would price them at what you think they should be priced as the quality of the OBJECT, as well as with a slight consideration for the COG aspects and the labor factor.  Just don't market them as "each made totally by hand forming".  If it makes you feel better, put "press-molded trivet" on the hangtag.  If someone asks how they are made... be truthful.  Simple.


Remember that "designers" get to charge a lot because ...well........ because they are "DESIGNERS".  But the objects sold are often totally machine made.  But it is good DESIGN of the object.  It is the design work that is the key.





#111717 Qotw: Are You Showing Us The Best Piece You Made When Starting With Pottery?

Posted by JBaymore on 20 August 2016 - 02:21 PM


Keep them coming folks........ this is interesting.






When do we get to see yours?



Will do for sure.  Wouldn't have asked it if I was not prepared to do this also.  Have to sort thru photos or old archived boxes of pots.





#111707 First Time Wood Kiln Fireing Questions

Posted by JBaymore on 20 August 2016 - 11:07 AM

John do you want ash build  in the fireboxes or would some ITC help there?


You want ash buildup pretty much everywhere.  Main firebox floor and the VERY lower side walls and the sidestoke firebox floors usually get washed repeatedly (zirconium/alumina works fine).... but since most folks stack stuff right in the fireboxes... nothing on the "above and around the work" area.


Typical anagama get better results with each firing as they "season". 


ITC does work for salt/soda... ...I've used it for clients..... and if it were a soft brick hot face I'd say for SURE coat it.  But not on hardbrick.  Talk to Fritz..... ITC 100 HT was not made for either hard refractories application OR for anything other than brand NEW IFB.  And yes... THIN coating is the answer with that stuff.  More ITC is NOT better.


Yes... the anagama kiln is slowly "dying" as the ash eats into the bricks and starts to melt the hot face.  Cost of doing business. 


From the woodfiring work I've done at the really busy woodfire place in Japan... we have a pretty good idea of the longevity of really good refractories in repeated long duration (4-7 day up-cycle) wood firings to cone 14.  A really good SK32 DP brick (about equiv. to US Super Duty DP) will last about 150 firings. 


My own noborigama here in NH looks to fit that number of firings model pretty closely also with good US materials.


So....... that kiln of Jawpot's will still last a while if it was built well.  About 25 years or so at 6 per year if they go hot and long.





#111467 Qotw: Are There More Male Or Female "well Known" Potters?

Posted by JBaymore on 16 August 2016 - 01:47 PM

The best student I ever had was a Japanese young woman who came to Rocky Mountain College in Billings and then transferred to Montana State Univ. Billings. Still friends.


One of our best NHIA under-grad grads ever was a Japanese woman, Chifumi Oi.  She came speaking almost no English (how she passed the TOEFL is anyone's guess).  Good thing I spoke some Japanese.  Amazing student and artist.  Incredible work ethic.  She had an undergrad degree in textiles in Japan before joining us.  Brought that influence to her hand-built claywork.  Went on to get her Masters in clay at RISD.  She's back in Okinawa now.  Still friends.  We've met up when I've been in Japan a couple of times.





#111330 Liability Of Making Lamps?

Posted by JBaymore on 13 August 2016 - 09:04 AM

 He says selling the lamp kits are out and suggesting what lamp kit to buy is out.  He says to market them as lamp bases and if anyone wants any more information about turning them into a lamp to send them to a lamp repair shop or to talk to an electrician.


Do you run every item you make thru your lawyers approval before selling?  What does he have to say about mugs, casseroles, teapots and the like?





  • Mug likes this

#111277 Going Gas, Need Some Direction

Posted by JBaymore on 12 August 2016 - 12:45 PM

You all love gas after you master it. 



Ah..... but beware the Dark Side.  WOOD firing!  MMmmmmuuuuhhhhhhaaaaaaaaahhhhhhhhhaaaaaaaaaaaaaa!  Electric leads to gas.  And gas leads to soda and salt.  And salt and soda lead to wood.  Take over your life, it will.





#111210 Going Gas, Need Some Direction

Posted by JBaymore on 10 August 2016 - 04:46 PM

Hi, so it's been awhile since I've been here on this forum. We've empty nested and moved to NJ from Mass. My studio contents have been in storage for the last 7 months. In a few weeks, I will have a house and a studio again! I have been taking classes at TASOC in Demarest to stay sane. I fell hard for the reduction look there. Since I sold my electric kiln before we moved, I am in need of a new kiln and plan to buy a gas kiln and fire to cone 6.


What I know:

There is a natural gas line right near the garage wall where I will set up (indoors). 

I will need the right size fitting to the kiln for the gas.

There is a high window that I can vent out of.

I probably will get a Bailey....


OK, that's it! ha ha not much.




-Can I bisque in the gas kiln?

-How much of the time during the firing do I need to be doing something?

-Will my cone 6 electric glazes look fabulous fired in reduction?

-Things to consider when shopping for the kiln? 

-Please recommend a good step by step book for firing with gas and reducing.

-I'd love to take a workshop but haven't seen anything.... have you?

-What do I need to know?

Thank you for any help!



attachicon.gif5Borg Teapot.JPG


Come see the reduction work I've done (but not fired myself) at Peter's Valley Craft Show Sept 24th and 25th!


You need to know the available pressure and VOLUME of gas that the gas pipe line and the meter leading to your property will accommodate.  The meter can be easily changed... the pipe cannot.  If you need more capacity than the pipe can handle... it is typically EXPENSIVE to get that kind of upgrade run.  You usually also cannot get the pressure changed easily if at all.  Your first step...... call the gas company.  THAT will tell you a lot about what the kiln CAN be.


Second......... check on your town's zoning and home business laws.  Make sure that you can actually do this.  If you sell your work... you are a business...even if you are not planning on selling out of that space.  This concept also leads to..........


Third, .....research your homeowners insurance situation.  Many will allow an electric kiln.. but not a gas kiln.  Some will allow an electric kiln or maybe a gas kiln for a hobby....... but not for a business.  Don't screw this one up.  You can maybe insure the whole property on business insurance... but that gets EXPENSIVE compared to the typical homeowners policy.


You are likely going to run into a lot of permitting and fire code stuff that you will NOT have with an electric kiln.  The Bailey and Geil units are AGA listed appliances... so that will help some.  Get to know the local building inspector and the local fire marshal.


You are probably not going to be able to vent out of that window.



-Can I bisque in the gas kiln?     Yes... remember everyone bisqued in wood and oil and then gas kilns before there were electrics.  In fact if you have good burners.. the potential for excess air is BETTER when bisquing in a fuel fired kiln than a static electric kiln... or even one with a downdraft vent.  The reason that electric kilns became popular for bisquing is computerized controllers.  They made what most consider a "drudge" firing simple.


-How much of the time during the firing do I need to be doing something?       You will need to attend to it frequently.... usually at LEAST every hour...for at least checking stuff like rate of climb and atmosphere and evenness.  Unlike the (bad) practice that so many do with computerized electric bisque firings (leave the kiln totally alone) .....you cannot do that with a fuel fired kiln.


-Will my cone 6 electric glazes look fabulous fired in reduction?        No way to tell this....every glaze is different.  And remember the "look" of reduction fire has more to do with the slow cooling of larger fuel fired kilns than the typical poorly insulated, low thermal mass electrics most potters use.  If you've been firing down in the past... you'll see some differences.


-Things to consider when shopping for the kiln?          The same consideration that went into your choices for an electric kiln in a lot of ways.  Both Bailey and Geil make good kilns.  The Blauu is the best on the market... but the price tag will kill you.


-Please recommend a good step by step book for firing with gas and reducing.      Unfortunately there is none.  "Gas Kiln Firing" by W. Ritchie used to be just OK.  Out of print now.  Olsen's "The Kiln Book" is certainly a helpful resource.  As is most any general ceramics book.  Best bet.... find someone to fire with and learn from them.


-I'd love to take a workshop but haven't seen anything.... have you?       If available, this is usually part of an undergrad curriculum in a college.  We take "special students" in my kiln (and glaze chem) classes.  Other institutions might also.  It is not often done in a short workshop setting... requires time and multiple firings to really learn much.


-What do I need to know?       Wow...... tons of stuff. Much too long to go into here... plus reading text and even looking at pictures is NOT the way to learn this stuff.  Find a local mentor.





#111061 Plasticizer/poreclain- Throwing Properties.

Posted by JBaymore on 06 August 2016 - 10:56 PM

I greatly prefer wet milled and blunged and filter pressed clay bodies.  Best way to get "good" plastic clay.  Which of course for tiles is amended to "bad" plastic clay. :lol:


Few to no US suppliers mix to slurry.  Tuckers does in Canada.


I've never yet made a porcelain pot that I am happy with...... with one single exception.  How I handle the aesthetics and the forms just does not "fit" in porcelain.  And I've not had the luxury of the time to spend to "find" my aesthetic voice in that medium.  I have one single porcelain yunomi that I made and wood fired in Japan that I have kept.  Oribe glaze.  The only porcelain piece that I have ever made and deemed even vaguely successful.


Gimme' a pile of gnarly, rock filled, non-plastic, large grained brown clay....... wet mix it....... and I'm happy B) .





#111053 New To Wood Firing

Posted by JBaymore on 06 August 2016 - 07:05 PM

A "manabigama" is the name for a specific very small anagama-style kiln designed by a specific person. (look it up.)  It is typically fired (by most people) for a shorter cycle than larger anagama.  Maybe two days.  Many large anagama are fired for 4 to 7 days.  While it can produce some very nice results, it is not known as a "heavy ash deposit" type of design.  The wares generally tend to be more "flashed" than "encrusted".  The pieces right next to the main firebox can get lots of ash... but further away.... much less so.  This has to do with the duration of the typical firing and also the size of the kiln and how that affects the draft flow.


For a manabigama style kiln I'd tend to do pieces with flashing slips added to "help" the kiln along.  Also use some American style high fire Shinos on some work.  Shinos are great in all kinds of woodfire kilns because they tolerate a WIDE range of cone endpoints, and simply do NOT run at all.  Most are fine from about cone 7-8 up to cone 14-15.  They take ash deposits nicely.  Many other high fire glazes can tend to run in extended multi-day firings even if the cone end points are the same as the typical 12-14 hour gas kiln firing.


A "woodfirer's trick":  On an unglazed form (even with flashing slip on the outside) put a liner glaze inside that is a high soda-ash shino.  The soluble sodium compounds in the glaze's water penetrate into the bisque and migrate to the outside also as the piece dry,.  This enhances flashing on the outside.


Watch out for lidded forms as a new woodfirer.  They have to be wadded very skillfully, and also not tend to warp due to design, forming, and clay selecdtion.  In extended firings, clay bodies that are fine at cone 10 in a gas kiln, can sag and move a lot over a multi-day firing.  This can cause the lid to slump down and make it not only not fit well (if you are lucky) but can also cause the lid and the base of the piece to come close enough to to each other in spots where the wadding is not... and fuse together from ash deposits.


Make yourself a couple of personal (gonna' keep em' for YOU) mugs.  Glaze the insides with a shino.  Decide on which side is the "face" (the side you want to be the focus).  Stack them face DOWN on their sides on scallop shells packed full of a refractory clay like a kaolin or a fireclay mixed with a lot of silica sand.  Set the shell holders on a little pad of the same kind of clay (like a sort of trivet).  Face the interior mug opening and the lip at a diagonal away from the flame path from the main firebox. 


When they come out do NOT try to immediately remove the trivet that likely will be stuck to the piece.  Place it carefully in a container of water.  That will cause the quicklime that the shells turn into (bad stuff....don't get it in your eyes) into soft goo and likely fully release the mug from the trivet.  If not tap judiciously until it does release.  Leave the mug in water after the trivet has released to continue to dissolve the remaining shell residue.  Lightly grind later with a diamond tool in a dremel to make it the w ay you like it..


You'll likely be happy.





#110945 Is it only me. . .

Posted by JBaymore on 04 August 2016 - 09:25 AM

Iron chromate (hexavalent chromium..... known carcinogen) colored slips/glazes are easy to convert to a far less concerning recipe.  Just add the proper molecular equivalents of red iron oxide and green chromium oxide.  Easy-peasy.  Looks the same.


However, I think that any risks to anyone from the firing of that slip or the handling of that ware before firing is minimal to non-existent.  If it is a "line in the sand" issue of no iron chromate in the studio........ well... I guess that is something that must get enforced to bolster a "follow the rules" culture.  But the exposure .... including intensity, frequency and duration aspects.... is nothing to worry about.


Handling the dry powder is another story.  But even then.... how much gets handled, under what conditions, and how often.


There is a lot of hysteria in the ceramics community about the hazards.  A huge portion of it comes from not really understanding the science side of things.  Simple concepts like parts-per-million, micron particle size, the form of the chemical (oxide, carbonate, sulfate, chloride, etc.), and so on do matter.  Yes... there are things to be concerned about.  But that means an appropriate level of concern.


Some folks are equipped with both the knowledge and the facilities to handle more toxic materials than others.   Like in a bio-hazard lab;  some staff working there are OK to work with the e-coli.... others are OK for working with the anthrax. 


Understanding the studio safety and toxicology side of the field of ceramics is just one more part of learning about the amazingly broad spectrum of working with clay.  If someone can't pull handles well...... most folks then work at getting better at that aspect.  So if you are weak on the H+S stuff (and the technical side to understand that aspect)........ make an effort to improve your understanding/skills there too.


Then you can appropriately evaluate for yourself which materials and procedures you are willing to work with, and which you are not, from a position of accurate knowledge. 


For people who are new to the field, and who would be expected to not know, those who are more knowledgeable do need to protect them from their lack of knowledge.  One route to that is to just BAN everything potential hazardous completely.  But a far better route, as soon as is practical, is to provide an accurate education on the subject.


I come back to this base concept all the time that everyone seems to want to ignore.  Clay dust is one of the more hazardous things that we are exposed to. It contains free respirable sub-micron silica.  Causes not only silicosis but also cancer.  Intensity, frequency, and duration are really important concepts in this one.  Comparing to the hazard of some dry iron chromate slip on some pots to be fired to the general dust issues in the average studio...... this is like comparing a firecracker to an A-bomb.  If you are concerned about health issues in your studio....... first priority........go after sources of clay dust in your studio.


Spend one day working in the studio that you keep a written diary of things you are doing that could get a little bit of clay dust into the air.  Once suspended in the air it typically stays there for over 24 hours.  Watch carefully for indications of this happening.   Sometimes you have to get the light 'right' to see it.   Snapping a dry plastic or wooden bat into place on a dry wheelhead....... poof.  Wiping your hands on the dry towel that wasn't really well washed out yesterday.... poof.  (Ditto for pants or aprons with dry clay.) Throwing down that slab on the dry table top....poof.  Moving used canvas cloth..... arrrrggggghhhhhhh ......poof.  Each one little in and of itself.... sum total potential impact on the air quality...... large.  You'll be amazed when you really start looking for this stuff.





#110907 Potters wheel comparisons

Posted by JBaymore on 03 August 2016 - 01:16 PM

I miss the days when Studio Potter Magazine would do impartial equipment reviews.  It was a service to the field.





#110723 Qotw: Are Our Expectations Too High?

Posted by JBaymore on 28 July 2016 - 06:29 PM

I have never accepted, nor will I accept that all "variables" in glaze firings are truly variables. Some yes, All no.


This is very true.  A lot of studio potters typically think that they have all the variables under control... but there are ones that have impacts that many don't even know exist.  Industry gets its consistency level by controlling as many variables as they can.  But even they have ones that are hard or impossible to control (at least economically) ...so they have some "gotcha's" sometimes also.


The "unknown unknowns" are the places that the "phases of the moon" solutions start to circulate in the studio pottery community.