Casting a Small Cone

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?


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

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

  • 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,

Hi Abigail;

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


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


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.


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
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