Dear Douglas, I know there are some issues regarding the
different expansion coefficients between gold and platinum that
you must take into account when planning a ring with these two
metals. Unfortunately, I’m not an expert on this! I’d suggest
you try calling Jurgen Maerz, director of technical education at
Platinum Guild International and describing your project to him.
I know he’s familiar with mixed metal work, and platinum is what
he does, so he can probably offer some (expert!) suggestions.
Platinum Guild International is in Newport Beach, California,
phone 949-760-8279. Jurgen’s e-mail address is firstname.lastname@example.org.
Hope that helps!