Thursday, September 8, 2011

Hump Dilemmas

Here is the sunburst glass platter from the previous post humped with clay. I used red clay with more grog to hopefully forestall any warping or cracking. I added a large foot ring. I used WD-40 for a release on the glass. It takes a lot of clay to roll out a 15 inch circle. Then picking it up and getting it on the glass plate without stretching the clay is another matter due to the weight of that much clay.


Anna mentioned making a plaster mold, but the glass foot ring has an undercut. So if I made the plaster mold the plaster would go in the undercut unless I covered the under cut somehow. Oh I could put wet clay in the undercut and fill it in temporarily. I will have to experiment with this.



I think this slumping over that foot ring may be a problem since when the clay starts to shrink the weight of the sides will not let it shrink back and up to the middle, if you see what I mean. Cindy mentioned she had problems with that. I know if I take the clay off too soon then the sides will flop and droop down. Cindy said she took her plates off and propped them with something when leather hard, I may have to do that and prop the sides with some soft foam. This is a perfect example of process of the trial and error of making new works in clay. Sometimes many pieces are made and discarded before a piece is perfected into an acceptable form.


Also the problem with using the plate as a hump mold is I'm not able to carve in any texture like the original glass plate. The bubbles in the center and the lines accentuating the rays of the sun are kind of what makes the plate sing. I may have to make a bisque plate, then use that as a mold and slump it and then I can carve it. I'm still thinking about how to work all this out. More ideas or suggestions are gladly welcome. Meanwhile I'll keep on eye on this attempt. Please keep your fingers crossed. Thanks for reading and for all your comments and suggestions.

16 comments:

  1. Hello Linda:
    Gosh, we have never really realised to just how many technical decisions have to be made to create a piece such as your sunburst platter. Alas, we are completely unable to assist as we have no experience with ceramics other than admiring their beauty and placing them around the apartment to be looked upon and handled with joy. We look forward to see how your resolve all these issues and to the final result.

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  2. Hi Jane and Lance, thanks, yes I never realized what all was involved either, I suspect many things the more you know the more you realize you don't know. Ha, keeps us from being bored though.

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  3. Hi Linda, I think part of the allure of working in clay is that constant search for new and better ways of creating and all the challenges needed to be overcome along the way. Does the glass bowl have texture on one side?

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  4. Hi Anna, thanks, the center of the plate has textured bubbles on the top and the lines on the rays are on the bottom of the plate. Since it's glass the lines show through the glass. If I could figure a way I'd texture only the top of a ceramic plate. Working with clay should keep my mind young. Ha.

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  5. Sometimes large platters have two foot rings to help stabilize them. Or you could 'stilt' the platter as it dries and when you fire it. Another tactic is to wrap just the outer lip with plastic so that it dries move evenly - the outer part will dry faster.

    Also you could use the form as a 'slump' mold and lay your clay across the texture - adding the foot ring(s) after you remove it from the mold.

    Clay is always a challenge :-)

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  6. Hi Judy, thanks, I've never seen two foot rings. I just checked the plate and the outer points are drying faster, I may go and just wrap them and not the rest. I thought about using it as a slump mold, but the underside dries slow and the top fast and then if it's too dry I can't attach the foot ring as the foot ring would be wetter than the bottom, but maybe I could make the foot ring at the same time and it could be drying too; I've never tried that I'll have to give it a try. Yep clay keeps my mind young, (hopefully). ha. thanks again.

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  7. Cool project! It's always a challenge to make a mold from something that was never intended to be one.
    I think your best bet might be to fill that undercut with a coil of clay, if I'm picturing it right. I think the slump might actually 'grip' onto the footring as it shrinks, so watch for that.
    Good luck!

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  8. what if you tried pressing the slab into the platter as opposed to slumping it? then add the foot wring when it is leather hard. just a thought i had, not sure if it would work this particular piece.

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  9. Being an appreciater but not a do'er, I can't help. Knowing you, you will solve the problem.

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  10. Hi Linda
    Get a pillow case from the thrift store..cut it along one seam and at the top so it will open as a large square.

    When you roll your clay out... (don't know if hand roll or slab roller) but if using a slab roller you will make be making your slab between canvas. Place your cut pillow case over the slab. Place something like a piece of sheet rock or some other thin sheet of wood under the canvas.

    visual layers....bottom up....sheet rock, canvas, slab of clay, pillow case, sheet rock (or some other thin sheet of wood).

    You will then be able to flip the slab of clay from the firmness between the two pieces of wood/sheet rock in one fell swoop onto the square pillow case.

    Then pick up the slab by picking up the cut pillowcase (now clay is on TOP of the pillow case)and place it pillowcase and all onto your form.

    By keeping the pillow case on the form and the clay on top of that...it will not stick to the form and will still be able to move as it dries. You can cover the clay on the form with a loose fit of plastic to slow the drying process just a little bit thus allowing it to dry evenly. Once at the leather stage you can flip your form and it should not sag but still be able to carve into the clay.

    You'll be able to add your foot ring before it dries.

    I know this is a long comment and I hope I've been able to explain it clearly. Good luck

    Ceci

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  11. If the patterned texture is on two different sides then perhaps the suggestion of having the clay on the inside of the plate to pick up the overall shape and then add your own texture when the clay is removed from the glass plate might work. Larger wheel thrown platters often have an inner and outer foot to prevent the clay slumping in the kiln. Keep up the good work :^)

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  12. Hi Brian, thanks, I think it might grip there too, it's got a slight depressing over the ring, I'm keeping an eye on it.

    Hi Michele, thanks, I haven' tried that yet, if this one doesn't work I'll try that one next.

    Hi Patti, thanks, we shall see what happens, never a dull moment.

    Hi Ceci, thanks, I've rolled slabs on sheets or pillow cases before, but never thought of leaving the piece on the pillow case, will the sheet wrinkle during drying and cause impressions in the clay? I'll give it a try next time or with another piece to see how it works out.

    Hi Anna, thanks, I'll try slumping next time. The plate slopes from the center so I am limited as to where I can put the foot ring and the center dips so it isn't flat but rough. It's such a nice size and shape, I'll keep trying till I get something to work. Thanks again.

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  13. Linda, sheet will not wrinkle under the clay. Just make sure the sheet is pulled smooth when you place sheet and clay on the form.
    Ceci

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  14. Hi Ceci, thanks ever so much for your advice and details of how to do all this, so wonderful of you to share your knowledge. I will see how this one does and go on from there. It really is a wonderful style plate for serving so festive and unique, who knows were this will lead. thanks again.

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  15. When you plant your Devil's Trumpet and it grows up, you can post it!

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  16. Hi Barbara, thanks, your devil's trumpet is so beautiful, I love purple. Ha.

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I love suggestions, questions, critiques, thanks for your comment