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Member Since 06 Apr 2010
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#120727 Is Cone 4-10 Clay Fired To Cone 4 Underfired?

Posted by JBaymore on 16 January 2017 - 09:04 PM


I would think because of liability issues they would also include: For Non-Functional Use Only.




You would think that.... BUT... and that is a big BUT.........  the ceramic suppliers do not indemnify the end users of their products.  So it I buy clay from XYZ Ceramic Supply...... and I make functional ware that explodes in the microwave....... it is MY problem with the consumer that bought that explodo-work from me.  I can't defend myself by saying, "Not my fault... it is XYZs fault".  I would have to settle with the client myself. 


THEN I would have to go after the XYZ place to try to recover my losses in the other situation.  Separate case.  Bet that they can afford better lawyers than I can.  And.... their product literature and websites and bills say quite clearly that they are not responsible..... test, test, test, ..........and that it is the end user's responsibility to see if their product is suitable for what they make.


So...... I'd lose.


Case of "Caveat Emptor".





#120587 Is Cone 4-10 Clay Fired To Cone 4 Underfired?

Posted by JBaymore on 14 January 2017 - 09:12 PM

So Nerd, I was hanging in and ignoring the brownies talk and all ... then you mentioned cooking a PRIME RIB roast to well done!!!
That is just an expensive, over fired error.


I think that qualifies as "carbon coreing".   ;)





#120563 John Baymore Solo Exhibition, Thayer Gallery, Ma Feb-Mar 2017

Posted by JBaymore on 14 January 2017 - 12:56 PM


#120408 Which Model Brent Wheel For School Use?

Posted by JBaymore on 11 January 2017 - 02:05 PM

I've had Model C-s stand up well at Massart and at NHIA where I've taught.  The CXC will stand up better though.


The reason for the CXC is not centering power,.... it is that the motor will be "cruising" in use.  less strain on it over time.  Also... that have better belts on the drive.





#120357 Xiem Trimming Tool Set Reviews?

Posted by JBaymore on 10 January 2017 - 11:33 AM

Hum....... have to see if I can find a picture of me trimming something.  Hard to verbally describe the position.  More on that later, if I can.


First of all.... you need a pretty slow wheel speed.  The "lathing" speed I see a lot of people trim at will not work all that well.  You can still get symmetrical if you want that......... without all the speed.  And you get production speed by cutting away a lot of clay at a time... not "worrying it off".


If you think of the flat blade of the tool as the reference point here....... as if it were a knife....... the plane of that blade part should be at a very shallow angle when compared to the plane of the surface of the piece you are trimming at the point of contact.  Think of how a shaving razor is oriented when is slides across the skin.  The plane of the blade is almost parallel to the skin surface.


If this character were the picture from the side view in cross section    <    the top part would be the blade of the kanna, and the bottom part would be the surface of the piece at the point of contact.  BUT....... this is a WAY too steep angle between the two.  To be a beter picture of the angle.... the V shape would have to get "squished" from the top down.  (Hope that helps.)


So the kanna is gripped along the handle and it is held WAY away from the piece.  The handle part comes away from the form at almost right angles.  For those used to more western style ribbon or loop tools... and even how I've seen people use the sharp Bison tools...... it feels REALLY wrong and "awkward".  Trimming the inside part of say a thrown teabowl, the kanna handle is almost vertical and the blade cutting part is almost horizontal.  When you do it REALLY well... it cuts out a perfect one piece spiral of a cut that sort of looks like a still tightly wound up spring.  Not a long continuous strip either.


Because of the slicing action, there is almost no "drag" exhibited on the piece as the tool cuts away clay, instead of "scraping" away clay.  This allows you to trim things that would be very difficult with a "western" type tool.  Should you choose... you can take off really thin amounts of clay... that resemble very thin potato chip flakes (can't think of anything else ;) ).


The real down side is there is a bit of a steep learning curve.  More so if you've trimmed a lot with the ribbon or loop tools before.  These things CUT.......... and they REALLY want to dive into the clay.  Everyone I have try them cuts thru a form in a heartbeat the first few tries.  Get that angle a tad too steep and ......... (picture those WWII movie submarine claxons going off and someone shouting "Dive!  Dive!").





#120339 To Wholesale Or Not?

Posted by JBaymore on 10 January 2017 - 08:51 AM

 Marking up your prices, then giving a discount, seems like unnecessary steps.


Works very well for car dealers!  ;)  :ph34r:





#120290 How Much Does A Refractory Castable Shrink On First Firing?

Posted by JBaymore on 09 January 2017 - 06:22 PM

If you are using a commercial grade castable, they specify it so you can get that #.  In all cases commercial ones shrink very little from the mold size.


A home-made castable... it all depends on how you make it (ingredients proportions).  Test a sample.


Casting full arches is tricky.  There are some tried and true aspects that you need to follow.  If you have never done it....... try to get with someone who has and learn how to fabricate it well.


Fired in place large casts are NEVER fully fired thru.  The hot face is fired.  The cold face isn't.  This sets up micro stress fractures parallel to the hot face.  This results in early spalling when compared to previously fired products.  The best way to use castable is to cast it, fire it to maturity ion another kiln, and then place it.  With large casts... obviously not a possibility for most folks.





#120152 Preventing Glaze From Running On Pipes

Posted by JBaymore on 08 January 2017 - 11:25 AM

Maybe James should expand his product line to include bongs to fill in the taller spaces. :rolleyes:



I'm not going there......... ;)





#120092 Is An Llc Worth The Money For A Small Hobby Business?

Posted by JBaymore on 07 January 2017 - 06:04 PM



This is a tough one.  No one can give you a "hard and fast" one-size-fits-all answer to that one.  You have to weigh the level of risks that you are willing/able to take. 


SO... no food items.  BUT.... you are making and selling even more potentially hazardous products.  Something with FIRE in it.  So what if your incense burner malfunctions (cracks or ??????) and catches someone's house on fire?  What if someone is hurt in that fire?  What if someone dies in that fire?


There are potentially big issues sitting there. 


What if someone's house catches on fire and they simply decide to BLAME your incense burner?  Now you are into a war with who hires the best lawyers.  Even if you win.... you lose.  Because of legal fees.


NOW.... all that being said.... how often does that stuff happen? 


Obviously not often or we'd be hearing about it constantly on the various pottery forums an in the press.  You can get about $2 Million dollars of combined premises liability, product liability, and tool and equipment protection as a potter for under $1000 a year.  That alone says it does not happen often.


I have talked to people who have had legal issues with oil lamps.  Don't personally know of any with incense burners.  I have to say that I stopped making oil lamps a long time ago..... out of concerns for product safety and potential suits.  I still make incense burners intended for Tea Ceremony.  For a VERY limited and "attentive" market.


Some people feel that HAVING such insurance makes you a target for suits.  Some people feel that if they sort of "have nothing" (no significant assets in house, bank accounts, stocks, etc.) then there is nothing to lose so why bother.


An LLC separates your personal assets from the business assets.  It means that someone can't take almost literally everything from you. 


Insurance and doing stuff like forming llc-s can feel like "wasted money" when all is good.  But that one time you NEED the protection..... it is a godsend to have the protection.  It is like medical insurance.  People complain loudly over the high premiums every month.  But then POOF....... a significant medical event comes along.... and the resulting hospital and doctors bills make all those insurance payments suddenly look like a REAL bargain.


That's all I can say on the subject.  I'm sure others will have opinions also.





#119816 New Prebuilt Shed For Studio?

Posted by JBaymore on 04 January 2017 - 10:02 AM

Here in my town..... just about EVERYTHING needs a Building Permit.  And if it is a "people work in it" space....... codes apply.  A "wood shed" type structure if it was less than a total of 100 square feet dimension would not need a permit. 


When I moved here....... 40 years ago......... you could do just about anything yourself (excavation, foundations, electrical, plumbing, additions, alterations, etc.) and unless you were building a new house.... you  didn't need a permit.


Too much regulation!!!!!!!!  We are now living in the "WARNING: hot coffee is hot" world.  It is nuts.





#119813 Not A Qotw, Just A Q.

Posted by JBaymore on 04 January 2017 - 09:52 AM

And best get over the notion of never "having" to work after retirement...that ain't gonna happen after all LOL. 


Unfortunately Lee, I think other than for the 1%-ers........ or those close to that situation........... American reality is that full "retirement" is a thing of the past.  Most people will have some sort of PT gigs that help pay the bills.  Besides....... as a clay artist... I can't see EVER fully "retiring" and not making stuff (unless health issues force that).


Sorry to hear about the car.  They have a way of doing that stuff, unfortunately.


Remember that John Lennon quote:  "Life is what happens to you while you are busy making other plans."   (Or something close to that.)





#119663 Lustre / Reduction Chemistry Question

Posted by JBaymore on 02 January 2017 - 10:31 AM

Nice work, Nerd.  You did miss one point in the above that relates to American Raku.  And the first "in your face" effect that tends to "grab" everyone's attention.  Copper luster.


If you reduce oxides of copper enough,...... what you are left with is...... copper metal.  Copper luster is a VERY thin layer of copper metal particles floating at or near the surface of the transparent (or even still green or red) glaze below it.  To achieve this, you need to hit the molten glaze very hot, and with very strong reducing conditions.  And hold that reduction situation until the copper surface is not able to re-oxidize when oxygen is again present.


Note that copper lusters tend to tarnish and gain a patina over time when exposed to air (with its oxygen).... just like any copper object.  Some American raku artists use sealants (acrylics typically) to stop this process form happening over time.





#119594 Really, Really Basic Question

Posted by JBaymore on 01 January 2017 - 12:33 PM

maybe not, john, what is the title of the book?


I don't write these initials often........ OMG!


"Clay and Glazes for the Potter" by Daniel Rhodes.  Last version  updated by Robin Hopper.





#119386 Raku To 05

Posted by JBaymore on 29 December 2016 - 10:42 AM

  But it does need a good gap between the burner and intake, so some of the surrounding air can get in, and help the gas burn.


Weed burners are basically "junk" burners. They are not intended for what we do with them.  They work just fine for what they are intended to do though........ because things that matter to us don't matter to someone burning off unwanted weeds.


The absolutely BEST available venturi type burners can entrain only about 65-70% of the air they need to combust all the fuel.  It is a limitation of the designs.  It simply cannot get better than that.  And those burners are not the ones typically used by the vast majority of studio potters.  Companies like Pyronics and North American make those types.  They are expensive.  (I have four Pyronics ones on my gas kiln.  They are precisely engineered and cast units.  Beautiful.)


So to burn all the fuel coming out of that orifice .... you MUST supply secondary air.  To do that... the burner/kiln SYSTEM must work together to entrain and MIX that extra 30% into the already burning and partly aerated mixture before it leaves the chamber.


The engineering start point for designing kilns is AIR.... not fuel.  No air...... no heat energy.





#119137 Equipment/tool Shaming/bullying

Posted by JBaymore on 25 December 2016 - 11:08 AM


I am pretty much self-taught and taught by YouTube videos to throw on the wheel. I had nobody to tell me specifically but I finally figured out a few months in that nearly every form starts with a cylinder. It follows that if you are very good at making cylinders (which I had never focused on making because I personally find a plain old straight sided cylinder pretty boring as a shape) you have the foundation to make almost any form you want from there. One of the biggest breakthroughs I had was from a little sentence in a wheel throwing book; it made me realize that I was curving my bowls up and out all at the same time which was causing them to buckle and collapse if I took them too much bigger, so I ended up with very thick bowls and lots of clay to trim at the base. After I learned that from the book I started pulling up, then angling out before curving the shape I wanted. I now use less than half the amount of clay I was using for bowls. Before, was I making bowls? Yes. Did they look nice? Sure. I could have gone on making them that way forever. But it was the wrong way because it wasn't having the result I wanted. 



You are beautifully describing right there one simple story that shows why basically books and online content do not take the place that good hands-on, in-person instruction will do.  Those "revelations' that you came upon are some of the most BASIC points taught in the very first couple of intro throwing classes.  Someone watching you throw would pick up on the fact that you did not understand those concepts in an instant from watching what you were doing, ... and give you the necessary feedback.