Need help from experienced casters

experienced casters - i need help! i just had a ring casted by
a jeweler who told me to make the ring 2 mm larger than what the
wearer’s size will be and to sand the ring down to make the
comfort fit. when i took a casting course two years ago we
carved in wax the comfort fit and just refined the fit when
sanding/polishing. now i’m stuck with a huge hunking ring and am
unsure of how to fit it to the client. is there a particular
burr or file i should use that will help me form the inside of
the ring? also, he had me make the wax 2 mm larger of the width
of the ring and i’m having a heck of a time sanding it down to
get the right width (have used rough adalox discs but they wear
down quickly and am hand-sanding it with rough grit sandpaper but
it is taking forever). also, for the diamond he carved and
casted a bezel setting that is extremely thick and high and
again, am having a heck of a time sanding it down and refining
it. any suggestions for burrs? i appreciate the help. marci
lebowitz (@marci_r_lebowitz)

Take the “0” Mill flat file or hand file to take the sides down
quickly. To put the comfort fit edge in I have used cartridge
rolls with a heavier grit and then work to a finer grit to break
it down. Or you could just used a coarser half round file and
then work to a finer cut half round…good luck!

Russ

Hi Marci, The jeweler gave you totaly wrong for a
one off casting in gold or silver.You should have made your wax
model exactly as you would have liked it to look
finished(remembering that you have to clean up and polish the
piece).

The only time that a wax is carved that much bigger is when a
wax will be converted to a master model that will be used to
create multiple production models (sizes 4 through10 or larger)
so that each size will have a model and mold of its own ,
eliminating the need to size the rings in mass production.

I suggest returning the metal for credit to the jeweler,

carving what you want , and have him recast it ,or send it to
someone like myself who does casting as a main profession.

If you want to take it down quickly and finish the piece which
sounds like a lot of work, I would use a cylindrical fine cut
carbide burr 1/4 " dia x 1/5 long to rough down the shape
internaly and externaly, then use small fiber wheels or rubber
wheels to smooth every thing out. Do the inside of the ring
first and put the ring on a ring mandrel to round out the ring
as you go along.

Hope this helps… check out the workshop at the adress below.
Daniel Grandi Tel/ Fax 401-461-7803
http://www.racecarjewelry.com

Racecar Jewelry Co.
PO box 10327
Cranston, RI 02910

Marci: It sounds like your caster needs some help of his own,
Yes the carving could have easily been comfort fit in the wax.
To add 2 mm to a wax is nuts in my book, but since it is done, I
would use a file to bring it down, rather than sanding. (that
could take weeks…) If you want to add a little to the wax
width in anticipation of some porosity, fine but you should make
the wax as exact to the wanted finished piece as possible. This
makes for much less work in the end for you.

Good luck. Jeff