I guess I’m an “ancient one”, since I have been sizing wax pattern
rings since 1978 or there abouts.
All the major tool suppliers and wax suppliers sell sets of
cylindrical half and whole aluminum ring sizes with a stand that are
very useful for sizing your waxes. We usually cast the original ring
in a size that is about as large as we would normally sell; 12 1/2
for men, and 9 for ladies rings. Waxes are easier to size down than
up. We make one or more vulcanized molds of each ring. Personally, I
prefer Belcone silicone mold rubber (Rio Grand has it).
I use a scalpel to cut the wax shank. If it’s going up several sizes
I inject 2 rings and splice in a piece to fill the void. You could
use a ring mandrel on a stand for this, but keep in mind that the
ring mandrel is tapered. This is really only a problem with wide
bands. We use an electric wax pen to join all ends, and build up the
wax a bit everywhere over the joint. This is all ground off as excess
metal in the clean up after the ring is cast. Clean up the inside
first, so you can tap the ring to the proper size. They shrink a bit
in casting, so the size comes out slightly smaller.
If your ring has a pattern all the way around, and you plan to be
selling lots of them in various sizes, it really pays to make molds
of each whole size. It’s not very hard to size a ring up 1/2 size
after it’s cast, in most metals; so that’s how we do 1/2 sizes and
1/4 sizes. If you size aring in the wax with a pattern, you will
need to fix, complete, re-carve the pattern where you sized it.
Hope this helps,
Paul; Ancient of Days