Forming spheres

[Anonymous]

Any ideas about how to hand build a shpere using a mold or some type? Would it be good to form it on the outside or form it on the inside of the mold? I want to make it out of small connecte pieces.

S

[imported_aclift]

Hi S,
If you are making lots of spheres the same size a mold would definitely be the way to go. See the mold below (minus the hole on the side).


This is a drape mold - much easier to remove the clay (half sphere) because it shrinks away from the peice :wink: . The opposite, a hump mold, clay will shrink around and actually hold on pretty tight.

As you use the mold, you can press pieces of slabs together, or try to use a whole slap, what ever works best for you, but just make sure, if you are using lots of slab pieces of clay, you really work the clay together on the back side, when it is pretty wet.

After pressing clay into the mold and completing one half sphere, let it set up, and then just make another using the same mold. Let that one set up, take it out and score and slip them together, when they are leather hard.


Good luck,
Andy

[Claudia]

I was going to try also using a balloon, for spherical shapes. Anyone ever tried that?

Also, can you buy those drape molds, or do you have to make them? I have plaster, but haven't made any molds yet. I guess you could use a ball to make such a mold, now that I think about it.

[plodder]

Hi all,
If you have the facility to throw some regular hemispherical bowl shapes and bisque fire them, they make great moulds for repeats; they remove the moisture from the clay more slowly and are less subject to damage (and contamination) than plaster moulds.

Andy

[HIgaki]

Hi. I've been using foam balls as molds for quite a while. Cover the ball with an old nylon to help the clay release - the ankle-hi or knee-hi size works great. Tie it off & cut off the excess. Roll out some slabs, wrap around the ball, and tuck & cut to make it fit. When the clay gets a bit firm - waaay before leather-hard, slice around the equator & remove the halves - best to make a squiggle somewhere so you can match up the halves again. Let them sit awhile to further firm up, then score & rejoin. Use a rib to smooth the joints.

This is great for making multiples of the same shape. I have several sized & shapes - some carved or squished for a specific form - to make bodies of creatures, etc. And once you have a clay "balloon" the shape can easily be manipulated further.

Jan

[claygranny]

Balloons will work and allow you to manipulate the form. Always rest in a shallow bowl with foam under so you don't get a flat side. Also, go to the local Goodwill or other thrift stores, they have a variety of metal and plastic forms. If the bottom of the form is flat, round it with a lump of clay, cover with a thin piece of cloth or plastic wrap (cover bowl as well) and build over that form. Get two the same size and they dry evenly so you can put together later.