Sculpey too lightweight, any ideas on making a small item weigh more?

I have made several patterns from Sculpey for a friend who does bronze castings of them. They are runes that end up on SCA helms. They measure 1.5" x 1" x 1/8".  Rune size. The problem is that my Sculpey originals have little or no weight to them, causing difficulty in getting them to shake out of the casting sand. (If they were heavier, they would easily fall out, we have to use a pick to lift them out, which messes up the sand) Any thoughts on making the Sculpey weigh more? 

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frollard6 years ago
Add lead or copper bb's to the middle of the sculpey? It's the heaviest you'll make that material.

Perhaps include in your design features (undercuts?) tight enough that sand wouldn't penetrate, but a pair of needlenose pliers could grip in/under....

Do the runes have a flat backside? Add a feature on that which is grippable by pliers or suction cup.

What about the pour-hole spout cutoff piece (name escapes me at the moment)? Can that be used to pry the original out of the sand?

compressed air...light blasts around the edge might dislodge the original.
dreamberry (author)  frollard6 years ago
I think I'm gonna try putting some lead in there as you suggest. Seems like that would give me the most weight for the thickness, I can hammer the lead thin and embed it within the piece. We're onto something here.
dreamberry (author)  dreamberry6 years ago
It works! Lead, hammered verythin, embedded, added quite a bit of heft. I'll drop it off at the blacksmith tomorrow and get his opinion, but I think it'll be fine. Juuust fine. I tried not to touch the lead too much, I guess it's not wise? We used to pinch splitshot with our teeth. Good times. :)
+1

>K<
dreamberry (author) 6 years ago
Here's the finished piece as cast in bronze (hot bronze) by GRIMR
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Re-design6 years ago
frollard - that pour hole cut-off piece is called "SPRUE" it think.
dreamberry (author) 6 years ago
Here are pics of embedded verythin lead sheet in Sculpey, and of the finished runes piece. Lead embedded before curing. Seems to have stuck in there real good, it will work for my purpose, this time. Gonna try Tungsten powder worked into the Sculpey next time. Thanks for all the input people!
PICT0006.JPGPICT0007.JPG
lemonie6 years ago

See if you can find any of these in the gutter.



L
dreamberry (author)  lemonie6 years ago
Oooohhh...free lead. (drools) I dug out my old tacklebox (unused for 15 years) and there were still some weights in there. I'm trying the lead embed.

I've got a handful, plus another one already melted and cast into billets. It's worth looking at the gutter sometimes...

L
Prfesser6 years ago
If you can find an online source of powdered tungsten, it might be mixed in with the sculpey. Tungsten is almost twice as dense as lead---19.3 g/mL vs 11.3 g/mL.
dreamberry (author)  Prfesser6 years ago
Learn somethin' new everyday. I'm getting some! You just won the no-prize!
oldmicah6 years ago
I've embedded a couple of times (this is the I don't know if it will work all the time disclaimer) stacks of super glued washers. That way you can tune both the diameter and weight. Plus you could use needle nose pliers (insert and spread handle method) to lift them out.

You could also glue a wire across the opening in between washers layers for a nice grip-able handle.
dreamberry (author)  oldmicah6 years ago
I like the wire grip idea. I'm gonna try that, as well as the embedded weight plan, but I think I will use lead fishing weights pounded flat and thin. Thanks for the reply!