After finishing Papa Bear, I decided to work on Mama Bear and Baby Bear together. I leveled the ovals out and then poured plaster for their cradles. Both models came out of the cradles without any issues so I poured the first half of the molds. I was unable to remove either one of the models after this first pour. I wound up having to break the molds to get the pieces out. Hmmm.... Try again. So, I verified that the models did not have any undercuts, reapplied the release compound (I've been using Murphy's Oil Soap), coddled the form up and poured it again. This time I was able to get Mama Bear to come out OK, but Baby still didn't want to budge. I decided to go ahead and pour the second half of the mold and then do one of Heather Mae Ericson's patented "break away" molds on Baby. Much to my chagrin, I realized after I had poured the second halves that I had forgotten to carve the keys for these molds (D'oh!). It was at this point where I remembered my first sewing lesson with my mom where she advised me to take out the messed up seam I had just made because I would never be happy with the skirt I was making if the seam was wrong. Since the same thing applies to molds, I decided to just pour the second halves again (good thing plaster is cheap!).
Well, this time Mama Bear came out OK, but, when I tried to "break away" Baby Bear I found that the plaster on the first half of the mold had seriously stuck to the model. This then lead me to do some research on mold release agents including a trip out to the RiNo district to consult with a master mold maker that I know. I returned from this trip with another 300# of plaster and about two gallons of steric acid (a.k.a. castille soap). The steric acid is a pure form of soap that many people use as a release agent.
I am now using the steric acid on my newly carved Baby Bear model and it seems to be working well. I also opted to create a clay cradle for the model on my first pour, rather than trying the plaster again. Hopefully this time there will not be any hang ups on undercuts, but things seem to be working well so far.
I am also working on a mold for a bowl in anticipation of the annual Empty Bowl event for the Crisis Center here in Douglas County. I don't know that I will make 100 bowls again this year, but I will certainly make a donation.
I hope you are all doing well this week and hopefully I will have some cast pieces to show you next week.