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aarrgghhh...I typed my whole spiel and the dang thing timed out and erased it all.

 

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.

 

I have read, watched videos, read more, and read again...but something is twitching in my brain to the point that I am just not "getting it" and not retaining any simple steps of what to do when.

 

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.

 

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? 

 

Please do not leave me with just "test-test-test". I absolutely cannot afford to expend my precious and limited supplies/materials experimenting just to get to a basic starting point.

 

Thanks in advance.  :wacko:

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Lee, I honestly don't see how you can afford not to test.  How else will you have any idea what your glazes and underglazes will look like on your clay body?  Tests are generally not very expensive to do; a couple pounds of clay thrown into a bottomless ring will yield a dozen test tiles.  If you're using commercial glazes, you need hardly more than a couple teaspoons of glaze to test it on the body.  A couple brushstrokes of underglaze will not noticeably diminish your supply.  It might be painful to fire a mostly-empty kiln, but that's better than firing a kiln-load of pots you end up not liking.

 

 Almost all greenware is bisqued to earthenware cones-- 06 to 04.  Underglaze is usually applied to naked bisque, and then glaze applied over that.  If you're firing to 6, that comes after bisque, decorating, and glazing.

 

So the sequence is: making, drying, bisquing, decorating, glazing, glaze firing.

 

You might be able to glaze a pot fired to cone 9, but it will be pretty hard to get the glaze to stick.  Glaze sticks easily to bisque because bisque is porous, and suck up the moisture from the glaze, accreting a layer of glaze.  Best advice is to heat the high-fired pot and try to spray glaze on.

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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.

 

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If you can't afford to test now you will be paying for it later. Its a i want to know now world, but knowledge is earned. Some knowledge can be gleaned from a good book, some from a good teacher but the knowledge you earn from your own hard work will take you farther. The reason you are not retaining what you are reading is because you have not spent the time earning the knowledge. You got to start doing and failing to learn what not to do. Its going to take a bit of supplies and some kiln time but the lesson will stick with you forever.

 

 

On a related note:

They say never help a butterfly to escape its cocoon because if you do the butterfly's wings will not be strong enough to fly, the work of escaping the cocoon prepares the butterfly for it airborn journey.

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Lee will be testing, testing,testing. Which I suspect she knew all along. Some people just seem bent on searching for the easier, softer way, which by now Lee knows does not exist most of the time and when it appears to exist, is likely to throw off the cloak of deception and eventually rear back and bite her. I'll do the ring-thing. 

 

THANKS! 

 

Flowerdry - I have a basic assortment of Spectrum, Duncan, Amaco, Laguna, & Coyote. Let's see....11 glazes cone 5 or 6, and 13 underglazes cones marked as ranged 04-05-06 (I avoided purchasing any single cone underglaze). I have 4 different bodies (red, white, gray, black), all cone 6. 

 

Good grief the number of possible combinations is insane!  

 

Well, my plan at the moment is to apply the under glazes to each of the test strips of the green bodies and firing everything to 05, then the applying the underglazes to a section of the plain bisque (cover with clear?) and apply the color glazes to the rest of the test strip. Fire to 6.  She hopes. We'll see what happens! 

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Depending on your kiln size you may be able to fill it with test tiles if you test all 11 glazes on top of each other. For under glazes I made a low, flat bowl with a hole on the rim. I went around it with the under glaze colors. I did this for both clears I use. Don't forget to put kiln wash on shelves before glaze firing. Remember to number test tiles and take good notes. Out of 153 test tiles the one I want to copy is the blank line in my notebook.

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Testing is a never-ending matter, either painful or joyful, depending.  I've been making pots for over 40 years but I still try to get a few test tiles in every firing, because the potential combinations begin to seem almost limitless once you have a handful of good glazes and good slips.

 

These are tests I've done since the beginning of the month.  Once you begin to get some complexity in your combinations, you almost have to have a pretty good space to write up the data.  For single glazes, I'd write the glaze name on the bottom of the test tile with underglaze pencil.  But with a couple slips and 2 or 3 glazes on each tile, I make a grid on a sketchbook page, so I can write everything down, including the order of application, and still have a little space to note the result.

 

post-65900-0-85035600-1432091574_thumb.jpg

post-65900-0-85035600-1432091574_thumb.jpg

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Great tips -not such a big deal after all, I see. I also found John Britt's demo for making test tiles, on YouTube, and I am more psyched than bummed now LOL.  In terms of space, they will either need to be on a wall board or in containers...can't believe how quickly my available space is disappearing! 

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For your test tiles, be sure to put a 1/4 inch hole in the greenware so you can hang it, those that you want to keep. You can put some pegboard up on a wall then either buy hook hangers or make hooks out of wire coat hangers. Good Luck

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I keep my test tiles on wire rings grouped by brand and then by color. The new tiles stay unwired for a bit then gets strung up on the wire. The wired tiles get hung in a corner of the studio.

 

Amaco potters choice has nice printed pages that shows thier results they get when they combine the different glazes. Not sure where the pages can be found, i have a student that brings them to me when he goes up to Sarasota to buy glazes. Can't say my results are always the same but it does give an idea to try.

 

I had a guy tell me i should sell my test tiles as they were kinda cool all grouped together...i looked at him like he was crazy...thats a lot of work testing all those glazes...i told him i'd have to do it all again if i sold them.

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