Casting a Small Cone

Jewelry Discussion
1

Hello Oh Wise Ones,

I need 20 or so small sterling cones – 4.5 mm closed top with a
small hole drilled in it, and 11mm open bottom. I have no experience
with casting at all, but I thought it would be simple to make one
model and send it to a casting service. However, I was told that it
wouldn’t work, that there was too much open space for rubber.

Is there any other way to do this?

Thanks.

2

I see no reason why this would not work, if the metal is thick
enough. I would suggest sending it to a more helpful caster, such as
Daniel Grandi of Racecar Jewelry. If it is not a good model for
casting, he will probably be easily able to tell you how to correct
it. (I am just a satisfied customer.)

M’lou Brubaker
Minnesota, USA

3

Whoever told you that you couldn’t cast it knows nothing about
casting or molding. You can mold it, and cast it, just fine. Just
make a silver model - or make a wax, cast in silver, and use that for
a model. Make sure it’s at least about 10% bigger - size AND
thickness

  • than your finished product. Leave out the drilled hole - it will
    only create problems. Leave a couple of dimples, if you want, for
    where to drill it. The biggest problem you’ll probably run into is
    getting warpage - pieces less than round, but that can be dealt with,
    too.

http://www.donivanandmaggiora.com

4

Hi Abigail;

I was told that it wouldn't work, that there was too much open
space for rubber.

Huh?

I can picture what you want, and I can picture it working fine. You
could make a vulcanized mold from a metal model, either one you
fabricate or one carved in wax and cast. You could also make a mold
directly from a wax model using RTV mold compound. If you don’t make
molds, most casting companies can do this for you, either from a
metal model or a wax one, and it shouldn’t cost much. $20-$30 dollar
range. Then, have them shoot waxes and cast them for you. Just make
sure you allow enough oversize for shrinkage and finishing, around 5%
should do fine.

David L. Huffman

5

Abigail,

However, I was told that it wouldn't work, that there was too much
open space for rubber

I only wish that I had the problem of “too much open space” when I
create molds. My usual problem is that I have filigree inside of a
channel with a closed bottom that has been fabricated (a real case
problem) with a ring that an individual wants replicated. Tough but
not impossible.

I, as others, can visualize what you desire. And, I think it was
mentioned the most significant challenge will be the wall thickness.
I just finished an Angel mold from a master that was stamped out of
20ga (appx 1/32) mild steel (tin). It was difficult only from the
perspective that the length (toe to crown) was about 3 inches and
the wax did not want to flow fully to the opposite end. A couple of
bleed channels and it works fine.

Assumptions:

Totally Hollow.
A rounded point on the cone since it is fairly wide.
Wall thickness 0.8 appx
Hole in either; vertical point of cone or horizontal near tip of
cone
Dimples was a great idea if horizontal.
Actual hole would work if vertical
Surface interior and exterior finish TBD

Sounds like an interesting challenge.

Guess I’ll have to make a stab at it next weekend when I have some
spare time.

Feel free to contact me off line and I’ll send a photo of the
results from next weekend.

Regards RLW