Relief MoldRelief Mold Hi All, (Please see prior moldtutorial for in depth info) Just a few more tips on mold making that I’ve learned:
I know this for a fact now. It was very cold in the garage (even here in CA) and so little or no evaporation occured thus, I could apply the silicone rubber thicker on the first coat than I did during warm months. Only problem is, the silicone cures very slowly, and if it gets too cold, risks not curing at all. My first layer took a day and half or more to cure before I could put on the next layer. Normally a day would be plenty long enough. Just to test out the theory that evaporation is causing bubbles, I brought the mold inside where it’s warm and within minutes bubbles started to create. Then I brought it outside and they stopped. In the past, I used a clear acrylic spray to seal in the moisture and thought that was good enough. After bubbles were created I wondered if the silicone was reacting to the acrylic spray. I found that it was not. The moisture was finding it’s way out of that layer of spray. I did an experiment with another piece of clay, one part was thoroughly dry and the other was leather hard (still with moisture in it). After spreading silicone over the whole piece, the silicone on the bone dry area was flat as can be – nice and smooth and no air bubbles. The leather hard area had oogles of bubbles all over it. Definitly moisture is what causes bubbles in my silicone rubber ( GI 1000 silicone).
Well, those are just a few points to share with you from this latest mold. Hope it is of some help to you. This pic below is similar to my other mold tutorial photos. You can see the back side of the clay wall is held up from falling by the use of T pins. I may be doing overkill on those keys by adding too many but hey, it works for me. I do think that if they rubber is thick enough then less keys is in order. The flimsier the silicone is because of being too thin, the more it needs to be held in place with keys. The front side of my silicone mold was plenty thick but the back side is probably a little under the 3/8 recommended thickness. I won’t do that again. On this relief it doesn’t hurt though. Next pics I skip ahead after the mold is completed and original has been taken out. While the garage is a mess is a good time to go ahead and try out the mold right away and see how it turned out. This plaster cast was ready to be taken out after a day. If it was a bigger cast then it would be good to even wait 2 days so that the plaster can harden and have less chance of breaking while demolding. The plaster came out nearly perfect with the smoothest skin. I’m very happy with how well the mold turned out. The original sustained damage as usual. That’s okay I’ll fix her back up and fire and glaze her. (See EDIT above regarding not filling in a spot on the mother mold in a critical place such as the face.) Thanks for watching everyone. Your comments are always appreciated. ~Tamara
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Email: tamarasculpture@sbcglobal.net |
Very interesting. Thanks for sharing. ZD
Hi Tamara, I saw you at the Sacramento Art Festival in 2009 and was very taken with the sculpture of the Indian Woman in a canoe. What ever happened to that piece? Do you have a photo of the finished product?
Thank you.
Thanks for commenting Maria.
Funny you should ask about that sculpture…. I recently had someone else ask about her too. Actually I got sidetracked but she is still waiting to be finished. Here’s some updated pics of her on my blog though: http://tamarabonet.com/blog/2010/03/16/american-indian-woman-sculpture-art/#more-597