Need Advice on Making Mold - Leia Necklace

[verdaera]

Hi,

Getting no advice in the SW Prop forum...

I finished my sculpt/carving for Leia's necklace from A New Hope out of green jewelers wax and I intend to make a two-part mold out of silicone. My first version of the piece will be cold-cast resin with aluminum powder but I'm hoping to build a small forge and make it out of aluminum or pewter.

I understand how a two part mold works but I've only made a couple one-part molds. I'm mostly worried about the undercut where the tabs are for the jump rings. I'm wondering if the best place for the part line is around the perimeter. My pour hole and sprue will be on the backside, but is there any advice you can give me? The front side will be the easiest to pack in clay, but wasn't sure I could do the side with the pour hole first?

 

[robstyle]

For your resin casts just fill the dog ears/folds with clay and cut them out on the cast parts. In the end whats more important from the time, work and cost investment, a bad cast without them filled in or a good cast that needs a little finish work. Filling them in will also cause less stress on the silicone when pulling castings. Youll want to tap, flip and work the mould around to expel possiboe air pockets and bubbles.

Ive a suggestion as well if youve never done soft metal casting. Get a cache of Crayola crayons, not knock offs, actual Crayola brand. Melt just enough down in a clean and dry soup can on the stove to pour a part, and have at it. The material is reusable and pours, drys and handles a lot like soft metal.

 

[spoudastis]

Absolutely fantastic sculpt. I have the same ambitions as you so I am very interested in your process. The sculpt looks just a bit large, but I could be wrong. The Lapponia website lists the length of the necklace as 42.5cm, if you divide that by the number of squares (15) plus a bit of gap (maybe 1.5mm) the squares come out to be about 2.7cm. Out of curiosity how wide is your sculpt?

Planetoid Valleys Necklace

Again, beautiful work!

 

[verdaera]

For your resin casts just fill the dog ears/folds with clay and cut them out on the cast parts. In the end whats more important from the time, work and cost investment, a bad cast without them filled in or a good cast that needs a little finish work. Filling them in will also cause less stress on the silicone when pulling castings. Youll want to tap, flip and work the mould around to expel possiboe air pockets and bubbles.

Ive a suggestion as well if youve never done soft metal casting. Get a cache of Crayola crayons, not knock offs, actual Crayola brand. Melt just enough down in a clean and dry soup can on the stove to pour a part, and have at it. The material is reusable and pours, drys and handles a lot like soft metal.

Thank you for the tips! And I'll have Star Wars crayons to give my nephew

The sculpt looks just a bit large, but I could be wrong. The Lapponia website lists the length of the necklace as 42.5cm, if you divide that by the number of squares (15) plus a bit of gap (maybe 1.5mm) the squares come out to be about 2.7cm. Out of curiosity how wide is your sculpt?

It's about 2.8cm, I went a *tad* large to compensate for any shrinkage since my reading had mentioned there might be some in the resin curing? If not I can shave it down a tad on the sides?

 

[spoudastis]

Right on, well it looks fantastic, following with interest.

Thank you for the tips! And I'll have Star Wars crayons to give my nephew

It's about 2.8cm, I went a *tad* large to compensate for any shrinkage since my reading had mentioned there might be some in the resin curing? If not I can shave it down a tad on the sides?

 

[verdaera]

I've been researching on Smooth Ons site and I'm a bit overwhelmed by all my options. Can anyone recommend what kind of resin I should get for cold casting with aluminum powder? I'm hoping for something strong as I'm a little worried about the rolled part with the hole for jump rings on the back, I don't want it to break...

 

[JPH]

Spray with Mold release (Ease Release) 200. Apply Rebound 25.
If you have a scale, I'd use EpoxAcast 690.
If you have a drill, make a skeleton of thin aluminum that seats in holes of your mold. When you pour the mold, the aluminum will be inside and provide extra strength.