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labricoleuseOur Costume Crafts Supervisor, Julia Powell, is an expert moldmaker and caster. During the regular season, she works in the Props shop of the Milwaukee Repertory Theatre (Milwaukee, WI), where she has been called upon to cast any number of bizarre things--including entire sets of "human" bones!
Recently she demonstrated how to create a flexible rubber mold to cast ornamental pieces for armor and jewelry, and i photographed the process to share here.
Because i was not on the ball with the camera, i missed out on photographing the mixing of the mold rubber--Julia took the pieces to be cast, laid them out on a smooth surface (NOT a rough one or the mold will stick to it and be a pain to remove intact!), built a "dam" around them with clay, hosed them with a release agent, and poured a mixture of equal parts of a Smooth-On mold rubber product into the receptacle...resulting in this:
The advantage to using a flexible rubber mold for these sorts of things is that you don't have to be concerned about undercuts--the object to be cast can be as sculpturally complex in relief as you want and it still works ok. When the mold had sat overnight (minimum 16 hrs), our intern Kelly Keough peeled away the dam clay and removed the solidified mold:
Here are the pieces we wanted to replicate, post-mold-making.
This is what the molds look like before casting.
(The one being made above is on the far right.)
Julia used the two plastic cups you see there to measure out the two parts of the material used to cast with--Smooth Cast 300, also a Smooth-On product. She first prepped the mold with some mold release--you want your cast to pop out of the mold, not stick to it and ruin it! To make the casting mixture, you measure out equal parts, then pour them together and mix with a stirring stick for maybe 1-2 minutes--the product heats up when it starts to set, and you don't want to mix so long that it begins generating heat, but you don't want to pour it without mixing thoroughly either or it'll make a sucky cast.
Here are the molds with the casting plastic poured in.
It's starting to set in the deepest areas of the mold!
Look at it go! Shallow sections harden last.
The gold pieces are the originals, and the mess of white ones are our copies!
Now we can make 29384822039 of them if we so desire.
(Luckily, we don't. That's a lot of casting.)
We'll be using these to ornament armor and helmets, and as medallions and badges in large stage jewelry (chains of office, huge brooches, etc.). This is a great way to do something like generate a ton of crests for a particular army's breastplates or similar.
And, because i'm a safety nut:
Casting and moldmaking chemicals are dangerous. If you try this at home, work in a well-ventilated area. Use a respirator with the proper filters when working with fine particulates and fumes/vapors, and cover yourself with a chemical-resistant apron and gloves, okay? Freaky lung diseases and tumors aren't cool.
Recently she demonstrated how to create a flexible rubber mold to cast ornamental pieces for armor and jewelry, and i photographed the process to share here.
Because i was not on the ball with the camera, i missed out on photographing the mixing of the mold rubber--Julia took the pieces to be cast, laid them out on a smooth surface (NOT a rough one or the mold will stick to it and be a pain to remove intact!), built a "dam" around them with clay, hosed them with a release agent, and poured a mixture of equal parts of a Smooth-On mold rubber product into the receptacle...resulting in this:
The advantage to using a flexible rubber mold for these sorts of things is that you don't have to be concerned about undercuts--the object to be cast can be as sculpturally complex in relief as you want and it still works ok. When the mold had sat overnight (minimum 16 hrs), our intern Kelly Keough peeled away the dam clay and removed the solidified mold:
Here are the pieces we wanted to replicate, post-mold-making.
This is what the molds look like before casting.
(The one being made above is on the far right.)
Julia used the two plastic cups you see there to measure out the two parts of the material used to cast with--Smooth Cast 300, also a Smooth-On product. She first prepped the mold with some mold release--you want your cast to pop out of the mold, not stick to it and ruin it! To make the casting mixture, you measure out equal parts, then pour them together and mix with a stirring stick for maybe 1-2 minutes--the product heats up when it starts to set, and you don't want to mix so long that it begins generating heat, but you don't want to pour it without mixing thoroughly either or it'll make a sucky cast.
Here are the molds with the casting plastic poured in.
It's starting to set in the deepest areas of the mold!
Look at it go! Shallow sections harden last.
The gold pieces are the originals, and the mess of white ones are our copies!
Now we can make 29384822039 of them if we so desire.
(Luckily, we don't. That's a lot of casting.)
We'll be using these to ornament armor and helmets, and as medallions and badges in large stage jewelry (chains of office, huge brooches, etc.). This is a great way to do something like generate a ton of crests for a particular army's breastplates or similar.
And, because i'm a safety nut:
Casting and moldmaking chemicals are dangerous. If you try this at home, work in a well-ventilated area. Use a respirator with the proper filters when working with fine particulates and fumes/vapors, and cover yourself with a chemical-resistant apron and gloves, okay? Freaky lung diseases and tumors aren't cool.
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no subject
Date: 2007-06-08 10:53 pm (UTC)Thank you for this coverage, by the way; i have wings to try and make (and screw up), so this is relevant to my interests.
no subject
Date: 2007-06-08 11:57 pm (UTC)And, you're welcome!