Rubber Molds: croissant butter dish update

What an opportunity to learn new things, these croissant butter dishes have been! In other words, what a frustrating saga full of dead ends and expensive new materials...

I have had an incredible amount of demand from instagram reels gone viral, and I've been working on developing ways to increase production to meet this new demand. With slipcasting, plaster molds are only good for a limited number of uses, before the details wear away. Additionally, I can only use the mold 2-3 times per day, limiting my production pretty significantly. The only way to get around this, is to create multiples of my plaster molds, by taking a mold, of my molds... How meta mold making can get...

I started this "master mold" process in March, by buying silicone to take molds of my original molds. While the detail reproduction was great, the silicone was actually too soft for making an exact copy of my plaster molds. When I poured plaster onto the silicone, the silicone was very slightly deformed by the weight of the plaster, and therefore the two plaster mold pieces no longer fit together EXACTLY, which is necessary to contain the liquid clay. How frustrating! I already spent a lot of money on gallons of silicone, and I was stumped on what to do next...

Luckily, the national ceramics conference NCECA was in Detroit in March, and there was a "Mold Doctors" panel lecture on the schedule. There, I learned that there are specific rubbers that are formulated for exactly my purposes, though they're almost twice as expensive as the silicone. I ordered $400 worth of PMC 746 by Smooth-On, and dove in (with a lot of trepidation!). It's a two part rubber that you have to mix very thoroughly, but with a pot life of only 15 minutes, so I had to work quickly but thoroughly with a brand new material! Yikes! Despite some struggles, the rubber set up properly on my first pour (over 2 half pieces that combine to make the top of the butter dish), and I was ready to remove my original mold. I pulled and pulled and jiggled and wiggled and leveraged and sweated, and my original would not come out of the rubber. SHIT! I ended up having to take a hammer to my plaster mold, and destroy it to remove it. No going back 😫

I was so so relieved when I removed my first plaster pours into the new rubber mold, that the new plaster just slid right out of the rubber. I was worried I'd have to break the new casts to remove them from the rubber, which would be a disaster. I used all my rubber on the first half, so I needed to order even more... I chatted with someone at the supply company (Reynolds Advanced Materials, in case you're going down a similar path), and got some great info on different properties and uses of various rubbers and silicones. There's a ton to learn! PMC 746 is the best product for this purpose, but there's a few other rubbers out there that will work as well. They're all crazy expensive.

Today, I'm going to make the second rubber mold of my plaster original of the bottom of the butter dish, and by the end of the day, I'll be able to pour new plaster and start producing new molds for croissants! The plaster molds need to dry out for a few days before I can start casting them with clay. I'm going to shoot for 4-5 copies of my molds, so that I can make 12-15 croissants per day, rather than just 3.

I'm getting closer to becoming a croissant butter dish factory! Your patience will be rewarded with a new drop in early June :) If you want a day's heads up before I restock online, sign up for my email subscription. The new release will go FAST! But I plan to have a fresh drop of croissants once every couple months from here out.