Friday, August 10, 2012


 This will be information many of you don't need, but if you are like me and have been making pottery for a long time and have never made a plaster mold, then this is for you! My pal Laura invited me to come out today and make plaster molds. She was making molds for her Vermont residency that starts next week (lucky girl) and I have never mixed plaster so I was up for a lesson.
 First you need a coddle. We also used a wooden box, but it didn't work as well, and we had sort of a hard time getting that mold out of the box. A coddle is the way to do it right.

 The wooden blocks on the end make it easy to clamp the boards together.
 We sealed the seams with clay coils
 Then brushed on Murphy's oil soap on all the surfaces
 add dry plaster to water. We used a little less than half a bucket of water and then slowly poured in the dry plaster. Make sure the bucket you use is clean and specifically used for the plaster. You don't want to get plaster in your clay! Also, get the plaster out of the bucket as soon as possible. We had some start to dry and it was hard to chip out of the bucket.
I like Laura's way of doing this. Much the same as I would have done it. You just pour in the dry to the wet until it "looks right". Look for the mountain in the middle, the plaster will start to mound up when you have the right amount. We didn't measure the ingredients, but I'm sure you could google this process and do it all technical. I like this way. One of the reasons I know nothing about making plaster molds is because I always heard how you have to have everything just so and how fussy it is. This was way simple and I plan to make myself a new wedging block tomorrow. Easy peasy....
Some potters out there may be laughing at this, but hey, it worked. Laura and I both do things that may not be the way "they say" to do them, but we seem to work it out. I don't make or use terra sig like any of the ways I have read online to do it, but I get great results! I don't fire raku the "right" way, but it works for me. You just try things, make mistakes and figure out what works for you. 
 Pour the thick but not too thick plaster in the coddle. Make sure you have something on your table to protect it. We used a thin sheet of plastic board. The plaster was a little thicker than heavy cream, didn't drip off the tip of your finger too much when dipped.

 Ta da! A great hump mold. I found this wooden mold at the Scrap Exchange in Durham, perfect for a little oval dish. I paid 50 cents for it.
If you want to make small molds just use some clay, seal it up well. Make sure there are no undercuts that the plaster can get hung up on.
I don't know about you but I learn best when I watch and participate. I hardly ever learn something by just reading so this was perfect. I feel confident enough to mix up some plaster and make some molds. Now everything I see is going to be mold potential!
Thanks Laura for your patience and endless generosity. You ROCK! I had a great time, hope you have a great time in Vermont!!!!!!  xo


Laura Farrow said...

thanks Trace! super fun having you and Wes out! I'm no expert on plaster, yo. But makin' do. xo

Tracey Broome said...

I'm not expert at anything, but I make it work!! We had a really great time! Thanks for all your help.

cookingwithgas said...

you are lucky to get a step by step- Mark and i do this together and some days it is all good and other days it is all wrong.
Great tips- thanks for sharing this.

brandon phillips said...

For my earlier molds and wedging table I used the "looks right" method that I learned in college sculpture class. This last year I made some new molds and followed the directions(an artist following directions?!!) and I've noticed a huge difference in the strength and resistance to chipping/scratching with the "correct" method. I also found it easier to mix having weighed out the correct amounts as I can just slowly pour in the plaster while using an electic mixer in the water. I'm not criticizing! Just passing along my experience!

Tracey Broome said...

Hey Meredith, it was definitely nice to have someone to do this with. We had a bit of all good and a bit of all wrong, but I learn a lot from the all wrong!
Hey Brandon! You're still out there! I know there is a right way and a wrong way and I do a little of both. There are some things I am a perfection freak about, and if I were making some serious molds,I think I would measure, but for a down and dirty get er done, this worked for me. This is why I don't do a post about how I do my terra sig, I would be leading people down a troubled path, haha! Nice to hear for you:)