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Making a Brushable Silicone Mold with Mother Mold Part 1 of 2

September 27, 2016

Brushable glove molds are used when a pourable block mold would be too complicated or difficult to make. A mother mold is a stiff backing that supports the thinner glove mold. Because gloves molds are thinner than a pourable block mold, they need help keeping their shape when casting resin (or other materials, like plaster) into them.

Materials needed:

• Original piece
• Silicone with Brushable catalyst
• Water activated plaster strips & scissors
• Inexpensive chip brushes
• Mixing containers & Mixing utensils
• scale that can weigh grams
• A piece of cardboard large enough for the original piece to fit on
• gloves

Your work area

• Clean, level work surface, covered in plastic or paper for easier clean up
• All materials comfortably within reach

Project Steps

• Situate the original in the middle of the piece of cardboard. You can use a bit of molding clay or a dab of hot glue to anchor the original if you like, but it’s not necessary.
• Weigh out the silicone Part A (in grams) and weigh out 10% of that weight in catalyst. For this piece, I did 200 grams of silicone and 20 grams of catalyst. It was more than I needed so for subsequent coats I cut it down to 100 grams of silicone and 10 grams of catalyst. Combine the two and mix well, taking care to scrape the sides and bottom of the container, until one uniform, consistent color.

• Apply the silicone to your original, starting at the top, in a thin, even coat. Make sure to work the silicone into all the nooks and crannies of your piece, as this is the coat that is picking up all the detail. At the bottom of the piece, apply the silicone about one inch around the base, to create a flange.

• Let cure for 24 hours.
• Apply the second coat a bit more thickly. Some people like to add a different silicone colorant to each coat to make sure they don’t miss any spots. I apply the silicone pretty methodically from top to bottom and I haven’t had any problems missing spots, but if you do, silicone colorant is an excellent solution.

• Let cure for 24 hours.
• Apply third coat and fourth coat as necessary, building up any indented or undercut areas. The eye sockets and underneath the cheek bones on this piece were pretty severe undercuts. I want to build them up so the ridge plaster mother mold will come away easily and not get hung up on those under cuts. If necessary, prop the piece up at a different angle to keep minimize the sag that comes from apply the silicone really thickly.

• Let cure for 24 hours.

I removed the original  from the mold just to show you how it looks. I put the original back into the mold afterward because the next step is to create the mother mold and we need the piece in the mold to do that.

And there you have it! A simple glove mold! In the next post, I’ll show you how to make a plaster mother mold to support the glove mold. The mother mold is important to help the mold keep its shape while casting.

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