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22 May 2013 - 15:42
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fuoco di forno
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Posts I've Made
Posted 24 May 2013Rather than discount your work ... or have "sales"....... all of which devalue your products in the consumer's eye (why buy full retail....... the true value is something less than that) ........ maybe make some small quickly produced items that you can ADD to the bag/ box when you deliver the order or piece at a show.
In Japan this is called "Sabisu".... "service".
It is a very pleasant surprise for the customer to get something MORE from you than what they paid for. It is very erffective. And keeps your prices as THE prices for your work. The nature of the "service" piece can vary with the overall sale price of the original item...... as you see fit. It could even be a quite high price piece on a VERY high end purchase or from a serious good repeat customer.
Sales and discounts are for competing with the philosophy of Walmart and KMart.
"Sell on quality, not on price." - Tom Peters -marketing abnd business guru
Posted 24 May 2013Tim,
So what is the goal for the shinos? Carbon trap? One just fire color? Carbon trap to the max (black shino).... or more subtle mixtures of color and blackness?
For heavy carbon trap.... you almost can't reduce too low. (Don't take that literally. ) For average carbon trapping I use about cone 010 as the starting point. With MY shino formulation if I get to about cone 05..... carbon trapping is not really possible anymore..... outer glaze surface is sealed over with highly soda fluxed glass.
Watch tenmokus in long duration firings.... they can run.
In my noborigama I have the luxury of firing different chambers in different atmospheres and to different end point cones... so I use all sorts of firing cycles. Some Japanese style shino I do has very, very light reduction at all... like much Japanese shino ware, the glaze is quite white with light red firecolor on the thin spots.
I don't think of "body reduction" and "glaze reduction".... it is all one continuum. In a wood kiln you are cycling from pretty strong reduction to pretty strong oxidiation on most every stoke anyway once you are at a certain temperature. I look at HOW HEAVY it swings to reduction on the stokes rather than holding it in a steady state of reduction constantly. The length of those reduscion periods also varies relative to the oxidation periods as the stoking rate.volume goes up on a single stoke.
As to downfiring.... on my last one or two chambers I often use the Bizen-style youhen charcoal technique.... and that REALLY retards the cooling and holds it in HEAVY reduction until the wares are not really reactive anymore.
Posted 24 May 2013Jim,
I'm very interested to hear the results.
Posted 23 May 2013I use a lot of different clays, but probably the one I use the most is cone 6 B-Mix. I think that's the problem. My reclaimed clay has no clay from throwing water and slip that has been dried.
You likely are right is the is cone 6 B-mix.
One of the problems with using commercially prepared "stock" clay bodies is that, because they are proprietary formulations, the manufacturers will not share the actual recipes. So we really do not know what is in there and what the proportions are. Makes troubleshooting difficult.
That being said, in order to get a cone 6 clay to really vitrify, the usual high fire (cone 9-10) kind of choice of a potash feldspar to supply the fluxing oxides for the body is not ususally going to work all that well. The proportions of fluxing oxides relative to silica and alumina in feldspars is not ususally providing the "oomph" to get the melt active within the body matrix. So to accomplish this task, the usual "substitution" that happens is to use some or all Nepheline Syenite as a partial or full substitution for a potash feldspar contribution in the body.
Nepheline Syenite is a SODA based material. THIS is where the potential issues begin. The potential issue with this is that Nepheline Syenite is slightly soluble in water (great for carbon trap shinos). And as the Ph of the water supply in the clay body changes.... the level of this solubility changes too.
So....... what I am driving at here is that it is possible that the older clay that has sat around a long time wet before use, and then wet formed and then slowly dried, and then picked up atmosphereic moisture when it was "dry", and then had water from YOUR water source (not the suppliers.....which MIGHT be Ph controlled) added to it.... the water chemistry of the re-mixed body is subtly changing as some sodium ions disolve out of the neph sy content.
This will cause the clay to go "short"...... and eventually when it gets bad enough exhibit some thixotropic qualities. So that might be part or ALL of what you are describing. It fits the situation that the beer and organic stuff growing does not help.
If you are not using a splash pan (like I do not) that likely means that you are throwing pretty dry (like I do). With your skill base, I am guessing that you are a pretty qucik thrower..... not working and working and working and working a piece to death. It seems to me that kind of forming profile would NOT wash out a huge amount of the finer particle clay materials to the extent necessatry to cause the shortness. THAT answer does not make sense to me.
Out of curiosity, do you find that if you let the bags of clay you get from the supplier sit around for a LONG time wet, and that the clay exhibits any similar "short" characteristics? Is it more plastic when you just get it than it is a year later (you might not order that far out)?
Thanks for replying, John. What you say about Neph Sy is very interesting and yet something else to consider. Commercial clay like B-mix rarely gets to be more than 5 or 6 months old but I've don't recall noticing any difference in plasticity between bought clay that just arrived and clay that I've had 6 or so months.
If you are game.... try running a coule of FRESH bags of the B-mix thru the pug as an experiment... and see if it "kills" the plasticity. My guess is that it will not.
If it is this neph sy solubility factor........ the longer the clay sits wet... the more the issue will evidence itself. Your accumulated scraps ageing is actually possibly making the matter a bit worse.
Posted 23 May 2013
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- July 19
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