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Can This Crack Be Repaired?


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So I pulled this out a bowl this morning and found a 1" crack.  I did not see it after bisque - and I looked.  How / why did this happen, any ideas? Can I grind it out and reglaze maybe? I don't see it on the back but when I fill it with water it slowly dampens the   surrounding area.

Thankscrack.png

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Ah, the infamous late-appearing S crack. Let's skip right to the end and then circle back. No, such cracks cannot be fixed. You can reglaze the area, but the molten glaze will simply flow through again. If you put enough glaze on and refire enough times, you might be able to plug the crack, but it would be plug ugly. Now, how/when did that happen? The reality is that crack happened when you were throwing the original piece. There are multiple probable reasons, including poor wedging, bad centering, improper opening, lack of compression of the opened base, and excess water accumulating in the bottom while throwing. All of these conditions will result in the center of the base being less compact than the side walls of the piece. As the piece dries, it shrinks, and the less compact center of the base will shrink relatively more than the surrounding walls. Because it is surrounded by the stronger walls that have shrunk less, the base will crack across the middle as the only way it can finish shrinking. The crack may not be visible after bisque firing, but it is there. There will be a second phase of shrinkage in the glaze firing, as the ceramic body reaches maturity and full vitrification. Any latent flaw will be finally revealed.

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