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Member Since 28 Jun 2010
Offline Last Active Yesterday, 09:58 PM

#82411 Large Flat Pieces Cracking During Glaze Firing

Posted by bciskepottery on Yesterday, 03:37 PM

You should be okay using sand during the glaze firing, too. Just make sure you leave some space between the sand and where your glaze starts. The vent should not be moving the sand around during the firing. Options to using sand include clay cookies allow the platter to sit above the kiln shelf, clay slats, or clay coils. But the key is to get the platter/flat item above the shelf so it cools evenly. The kiln shelf retains heat and cools more slowly as it is thicker than your pottery (except for sculpture). Allowing the item to cool above the shelf minimizes the chance for uneven cooling and cracking.

#82311 User Program, Does Anyone Use Ramp Rates Different Than The Orton Chart?

Posted by bciskepottery on 23 May 2015 - 04:51 PM

Slowing down the last 200 degrees allows the glazes and glaze ingredients to melt more smoothly than a more rapid increase. It can also help the kiln to even out heating from top to bottom. Makes no difference between stoneware and earthenware or porcelain glazes.

#82253 General Liability Insurance

Posted by bciskepottery on 22 May 2015 - 07:44 PM

Sponsors requiring insurance by vendors is not unusual; that amount seems typical. Your life or homeowner insurer (e.g., State Farm) can offer a policy; also check of CERF+ (Craft Emergency Relief Fund) http://craftemergenc...o_be_without_itfor info and, I believe, they also offer coverage.

Why bother? Customer cuts their hand on a rough or sharp edge. Kid pulls over display shelf onto him/her self and gets hurt. Customer wants to sue because they burnt themselves on mug handle after heating in the microwave. Etc. We live in a litigious society. A couple hundred per year is cheap compared to some lawyer putting a lien against your house, car, savings, property, your 401K, your pottery collection, etc. Your homeowners insurance does not cover this type of thing. And, the sponsor is going to wash their hands and say, it is your responsibility -- look at the contract you signed.

#82197 Group Studio: How To Figure Out Cost Sharing

Posted by bciskepottery on 21 May 2015 - 08:17 PM

Attached File  Kiln_Firing_Cost.pdf   179.28KB   16 downloads
Here is an example of how to compute the cost.  You need to identify your variables, costs of the variables, and assumptions of life-cycles, etc.

Attached File  Kiln_Costs.jpg   35.94KB   0 downloads

#81900 Commercial Glaze Sequence

Posted by bciskepottery on 18 May 2015 - 10:37 PM

OK-seeking a simple starter lesson on the sequence of greenware/bisque/mature fired AND with the proper sequence of underglaze and glaze relative to the firing sequence...not clear on the fit of the cone of the body and the cone of the glaze when it comes to the variables.

Underglaze can be applied at either the greenware or bisque stages; it is a matter of personal preference and, in some instances, technical approach.  I like to apply underglazes at greenware stage when I can as it gives me a chance to touch up the colors before glazing.  Also, applying at greenware stages can minimize any smudging of the underglaze when applying the glaze coat -- especially if you are brushing on a commercial glaze.  If  the work is fragile, you might want to wait until after bisque firing to apply the underglaze as the piece has more strength. 


Overglazes are applied after the glaze firing and then refired to a low temperature to set or melt the overglaze into the glaze.

I have zip experience with commercial glazes. I had worked with cone 10 studio-made bodies, gas-fired, and sometimes, not that often, with high-fire studio-made glazes, generally very earthy, not a color palette as with commercial products. So I have no clue about low-fire underglazes and mid-fire bodies, for example.

When using commercial glazes, just make sure the glaze cone matches your clay firing cone.  More and more, commercial glazes are being engineered to fire to mimic the results obtained from studio glazes that are fired at high temperatures.  Some potters use lower firing glazes on top of higher firing glazes with good results after much testing (sorry about the T-word); see Fong Choo's teapots; a word of caution though, I understand he has a good rate of failure on wares as this combinations are unpredictable.  But I'd stick with commercial glazes for your clay bodies to start.  One problem, as noted in other threads, is that some mid-fire commercial glazes are rated Cone 5, but the clay is Cone 6.  Some work when pushed to the higher temperature; others do not.  You only find out by firing.

Also wondering if I can take an unglazed piece fired to cone 9 and glaze with a cone 6 glaze and re-fire at cone 6?

Yes, but not always easily. If your clay body vitrifies at cone 9, then it will have difficulty absorbing the water from the glaze. To overcome this, some folks will heat the unglazed piece and then apply the glaze. The water from the glaze will steam off the warmed up piece of pottery, leaving behind only the glaze ingredients. Others will spray the piece with an adhesive -- spray starch, hair spray, spray glue, etc -- to create a surface that will hold the glaze. Once you get your glaze on, the fire it. It may take a couple of items before you get a sense of how thick the glaze needs to be.


#81890 Setting Up Studio In Basement

Posted by bciskepottery on 18 May 2015 - 06:38 PM

To transport greenware and glazed wares, I use the boxes vegetables are shipped in . . . I put a piece of 1/4" foam (from the fabric store) on the bottoms and place wares on the foam.  The foam prevents them from shifting around and serves as a nice cushion for road shock.  I also use pieces of foam cut into 1/2" to 1" strips to place between wares so edges do not not make contact and chip.  For glazed wares, use spray starch as noted or cheap hair spray.  Just put the glazed pot on your wheel or banding wheel, give it a slow spin, and spray.  The hair spray dries to a thin protective layer and burns off in the kiln without affecting the glaze.  When the hair spray is dry, put a plastic bag over the ware and pack it in the cushioned vegetable box.  For taller items, like vases, I use a wine box -- one with the 12 separate spaces for bottles.  I put the wares in a plastic bag (the ones your morning newspaper comes in are real handy) and then set them inside the wine box. 

#81693 It's Too Big..she Said

Posted by bciskepottery on 15 May 2015 - 12:13 PM

at the pottery studio where I belonged to a guild I overheard a fellow potter tell another potter that 'handbuilding' isn't REAL pottery like something made on the wheel. :/


Those are usually the people who tried handbuilding but could not make it, so they moved over to wheel classes. 

#81450 Sometimes I Wonder How In Heck Did I Gift This?

Posted by bciskepottery on 12 May 2015 - 08:25 PM

Seeing older work and wincing is part of  the growth and evolution of your skills.  Everyone goes through it . . . even the biggie names.

#81361 I Need Help With Bone Dry Clay

Posted by bciskepottery on 11 May 2015 - 09:32 PM

I've never really understood why school and community firers don't take this approach, rather than risking blowing something up.  How much extra can it cost to keep the kiln under 200 F for an extra hour or two?



Most of the sculpture we fired at the studio was brought in by artists taking classes at one of the more upscale Art studios . . . and their kiln techs apparently fired everything the same way.  They brought stuff to us to fire because we had a higher survivability rate . . . even though they had to pay for our firing vs. getting it fired for free at the studio where they took classes.  I could never figure that one out.  But we would preheat a sculptue load any where from 6 hours to 18 hours depending on thickness, size, and complexity of item.  And then we would do a slow bisque.  The only thing we refused were solid items . . . they were certain to crack, break.  And we took care to fire on thick beds of grog. 

#81331 Any Way To Get An Off Topic Forum?

Posted by bciskepottery on 11 May 2015 - 06:54 PM

In oh so many ways, the software used for the Forum is not what you want to use for social media.  The Forum has over 14,000 members.  And, it allows non-members to parse the various topics and threads.  Just now, the ratio of guests to members is about 7 to 1.  And, Google, Yahoo, Bing, and numerous other search engines document the topics and threads -- all available to anyone doing a search on a work, person, or topic mentioned in the forums.  All of our conversations -- and their content, both pottery and ceramics related and the personal tidbits of info we also include at times -- is out there for the world.  Seriously, is this the place you want to have "off-topic" conversations which may tend to be highly personal . . . shared with the world? 


There are far better platforms available to do that type of messaging without the fear of having a bazillion lurkers reading your every word.  CAD chose a fairly good blogging software application for the Forum; that requirement is not the same as what you would want in a messaging software. 

#81312 Community Challenge #2

Posted by bciskepottery on 11 May 2015 - 04:30 PM

The rules posted above state that only one image be attached to an entry.  Sometimes my work has four sides, each decorated totally different.  So one image wouldn't really show the decoration for the entire piece.  I could possibly photograph it at an angle to show two sides in one photograph, but the other side couldn't be shown. Is there anyone else out there that might have this same problem? (Well, not really a problem, but you know what I mean  :rolleyes: )  


Photograph two angles from front with mirror in the back to show the two back sides.  Or use a photo editor, like Microsoft Paint, to join two separate photos into one. 

#81225 Cone 5 Kiln?

Posted by bciskepottery on 10 May 2015 - 08:20 PM

Whether the kiln is sufficient depends on what claybody temperature you plan to use.  If you are staying at low fire, then a cone 5 kiln will suffice.  But if you want to go mid-fire range, cones 5/6 for example, you may want to find another kiln option.  A kiln capable of at least cone 6, but preferably cone 10, would give you the most flexibility for now and the future . . . perhaps when you are making work other than the mold-forms you have come into possession.  Don't just think about today's need; plan ahead.  A kiln is a big investment -- even used.  And, if you only have space for one, you need to think about the best option for using that space.  But it comes down to what clay you will use and need to glaze. 

#81119 Ok, This Is It, Opening The Kiln

Posted by bciskepottery on 09 May 2015 - 07:19 AM

In every kiln load, there needs to be those items for the sales table and some items for yourself -- to give to your friends or keep for yourself.  That is your balance.  So, go ahead and keep some for yourself. 

#80963 I Want To Wind My Own Kiln Wire For A Scutt 2327 And Olympic 2327

Posted by bciskepottery on 06 May 2015 - 08:33 PM


#80874 How Common Are Exclusivity Clauses? (Long)

Posted by bciskepottery on 05 May 2015 - 08:56 PM

Legally, unless the clause is in the original agreement that was signed and submitted, adding a clause after the fact may not be enforceable.  Check with your local legal aid society for a read out.