When sizing, make the ring 1/8 size too small. Clean the solder
joint on the inside of the ring only. Next, place the ring on a
ring mandrel and hammer across the solder joint until the ring
reaches the correct size. Finally, clean up the outside of the ring
with a file, emery, and polish the ring. This will help you to be
more accurate in your sizing (if you are a little too large you will
need to resize). In addition, this will work-harden the sizing area
making a stronger joint, and finishing and polishing will be easier.