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Chilly

Design options to prevent bending

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Last year I made 20 Herb Labels and a stand to fire them in, so that I could glaze both front and back, leaving an unglazed are that would not be seen as it would be below soil level.

It sounded like a great idea, but in a ^8? (1260c) reduction gas firing, the labels leaned and most of them stuck together and/or curved.  The stoneware clay was rated 1120c to 1280c.  (Yeah, yeah, I know about clays that are rated for a wide range, but.......) 

I'll be back at Potter's Camp again this August, and want to have another go.  My clay choices for this year are:  same as last year or porcelain rated 1220c to 1280c.    I could fire them in salt, soda, gas or wood.  The salt and soda firings are expected to go to 1280c.

I still want the same design, glazed both sides, and have been pondering since last August how to construct them so they do not slump.

My first thought is to hang them upside down, so gravity isn't trying to flatten them.  Does anyone have any thoughts on this?  

There are photos of last year's failures and my thoughts on supporting the upside-down labels in my gallery.  Gallery

  

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so sorry your hard work did not pay off.  hanging through that hole in the center design looks like a good option.  can you somehow try one or two before the camp?

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Reverse your firings.

Glaze the tops and fire them to maturity flat on the shelf. That way nothing slumps.

Use a Cone 04-06 glaze on the bottoms, fire them in your holder. That low of a firing will not mess up your high fired glaze and it won’t be hot enough for your items to slump.

 

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18 hours ago, oldlady said:

so sorry your hard work did not pay off.  hanging through that hole in the center design looks like a good option.  can you somehow try one or two before the camp?

Can't fire higher than 1200c at home, or around 1260 at the centre.  Both electric.

16 hours ago, Magnolia Mud Research said:

How thin were these items?   Did the items have stiffening ribs?  

Remember,  Thin sheets of paper will not stand up but cardboard will. 

 

 

Fired thinness = <4mm

Good thought, no stiffening, completely flat.

13 hours ago, yappystudent said:

Holy crap, you sold a tile for 2.8 mil>????!!!

Oh, yeah, I wish.

12 hours ago, neilestrick said:

Make them thicker.

How thick?  10mm?

11 hours ago, Chris Campbell said:

Reverse your firings.

Glaze the tops and fire them to maturity flat on the shelf. That way nothing slumps.

Use a Cone 04-06 glaze on the bottoms, fire them in your holder. That low of a firing will not mess up your high fired glaze and it won’t be hot enough for your items to slump.

 

Sorry Chris, not sure I get this.  If I glaze front and back, I can't fire them flat.   If I bisque fire to 1280c they won't take the glaze.  I want them high-fired, so they'll survive a wet winter out-doors.  Lowest temps here are around -5c for less than a couple of nights a year, but because they'll be wet, even -1c could be a problem.

I don't want or need the bottoms glazed.  Seems a waste when they are out of sight. 

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Make the pieces, glaze the front only and lay them flat for the first firing which will be a high temp to take them to maturity. Since they are flat you won’t get slumping. Then use a low fire glaze on the reverse and fire in your stands to Cone 06 which will be too cool to cause slumping. A lot of potters never consider that you don’t have fire in ‘low to high’ order ... fire the way you need to.

Also. as a side note ... I leave all kinds of Pottery outdoors throughout the year and never lose a thing glazed or unglazed and we do get freezing temps. My worst damage is from deer knocking things over.

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I'd recommend firing them on 1/4" coils. laying them flat will prevent slumping , but not warping from uneven heat up. Edges could curl up, Dry them on sheetrock and edge the sheet rock with tape to prevent crud o' plaster.

M

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1 hour ago, Chris Campbell said:

Make the pieces, glaze the front only and lay them flat for the first firing which will be a high temp to take them to maturity. Since they are flat you won’t get slumping. Then use a low fire glaze on the reverse and fire in your stands to Cone 06 which will be too cool to cause slumping. A lot of potters never consider that you don’t have fire in ‘low to high’ order ... fire the way you need to.

Also. as a side note ... I leave all kinds of Pottery outdoors throughout the year and never lose a thing glazed or unglazed and we do get freezing temps. My worst damage is from deer knocking things over.

Thanks Chris, understand now.  Unfortunately, I won't be allowed enough space to lay them flat.  I need to get as many into as small a space as poss.

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A charming idea, Chilly! Could you consider changing your design a little? A rectangle above a vee (the stake) could be folded slightly (like an open book), or curved enough to support itself, and fired upside-down, leaving only the top edge unglazed and possibly colored with a thin oxide wash. 

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Maybe a complete change in the design option. Instead of using the all in one stake idea, make your ovals or round discs with a hole in the bottom going up into the piece that will allow a bamboo skewer to fit. Then fire the pieces with glaze using row kiln stilts, placing them on the vertical wire with the hole. They are the ones with the kanthal wires sticking up straight in long single rows. This way many could be fired and glaze on both sides. The stilts would hold up to several firings. Then when glaze load is finished, cut your bamboo skewers to an appropriate length for the soil depth and insert with a bit of silicone putty to seal into place and waterproof the hole.

I love the single piece idea, but with some of the solutions I think there is more work than progress. In the end you have to figure that maybe there is a design flaw somewhere that needs corrected. Such for me would be the peg themselves. The only problem with this is finding the right size hole for the bamboo skewer after all shrinkage is completed. However, I would think nails would allow you to find the right thickness by doing some test slab with different sized nail holes to find one that works.

 

best,

Pres

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