hydro stone slump mold

[elaine clapper]

Trying something new... I have always worked on the wheel and not done much with slabs or molds. Recently, I purchased a 10"x5" hydrostone butler tray slump mold. I am thinking of texture design work on the inside flat surface of the tray.  My plan is to roll out the clay on cloth, put the mold on top, flip it, let the clay sink into the mold, pull off the cloth, do my design work, let it dry slowly until I can flip it out of the mold.  Am I on the right track?  I would appreciate any helpful hints...

 

[oldlady]

elaine, sounds fine to me.   i have found that when i carve things into the face up area that sometimes some sharp bits are left from the edge of the cutting tool.   i use a stylus for most of the work but to eliminate the possibility of leaving something sharp i  lay a finely woven curtain fabric  on top and slide my thumb over the whole piece.   adding slight pressure flattens those sharp bits and lets me see if something needs more attention.   the fabric i use does not transfer thread marks to the work and prevents obvious thumb prints.

have fun with slabs, they do amazing things because you can catch them at just the right moisture level to do about anything you can think of.

Edited January 14, 2023 by oldlady

[Pres]

If you were working with a slump mold, I would decorate before shaping on the form, but you have the right idea about the slump mold, as you would blur your decoration in areas trying to get it to shape into the slump mold. @old lady has a good idea for the woven curtain fabric, another option is saran wrap. I have also used tools that have a small ball on the end for incised lines as it does not raise as much of a burr, these also glide easily over saran wrap on clay as do roller stamps.

 

best,

Pres

[elaine clapper]

Thank you , both the Saran Wrap and drapery fabric are good ideas. What about drying?  I always dry my wheel work upside down.  I am thinking with the slump mold I should keep it right side up.

[Min]

For drying flat slab pots I always weigh down the center of the pot to avoid it rising up as the edges dry faster than the inside. I usually use a square or triangular kiln post on its side, with really large slabs I put the kiln post on a batt to distribute the weight. I keep the weight on (especially after Christmas, ) until the pot is bone dry. I keep slab pots right side up.

[Kelly in AK]

I like slump molds because clay shrinks away from them and I don’t have to babysit to prevent cracks. I’ll confess I’ve forgotten about pieces in a mold and when I finally got to them they were totally fine, just dry. On the other hand, putting a foot on pieces is easier with  a hump mold. I do some plates and trays using slump molds and simply don’t bother adding a foot. 

 I usually lay the slab into the mold and use a pounce bag to really get it set into place. That’s not great if you have an elaborate texture you’re trying to preserve. I add texture after the slab is in the mold (which has it’s own set of tricks).