Post #564197 by MadDogMike on Mon, Nov 8, 2010 9:25 PM

On 2010-10-20 19:33, MauiTiki wrote:
Mad Dog, I'm new to all this, plus I live on a rock in the middle of the ocean so have limited supplies and resources. I have slip, but not clay. I don't know anything about press molds or how to do it. I'm just experimenting and learning as I go. How do you get the clay out after you press it into the mold? How do you press it in all the way? I think I would need more exact molds. The slip is easy to clean up.

I don't pour out the excess slip, it all dries pretty quick. they are only 1/4 inch thick. I sand down the backside to make them smooth because the slip leaves the edges taller as it dries. The final pendants are about 1/8 inch thick and pretty lightweight.

yeah, the slip shrinks which makes them easy to get out of the mold. I don't have a problem with them shrinking a little.

-Rob

Rob, sorry I missed your reply and question

The mold you are using for slip would probably also work as a press mold too. You just stuff the mold full of clay and use a straight edge of some sort to scrape off the excess clay. It shrinks as it dries too and the molded piece pops out.

If clay were available, it would probably be a little cheaper than slip but otherwise there is very little difference. I would imagine that the slip shrinks a little more just because it has a higher water content

Again, it probably doesn't make much difference at 1/4 inch thick, but you could probably dump the center out of the wet clay after about 10 or 15 minutes. It would make the back concave and a little little lighter. The advantage of a slip casting mold is that the slip forms a skin starting on the outside (plaster contact area) and the inside can be poured out. It doesn't have much bearing in this application but it's the MAGIC in mug making because you end up with even thickness walls on your mug. Have fun!