Dear Gustavo, I have seen the literature on Cobb precise white gold
but have not tried to cast this alloy. They do indicate special care
in casting. Also, special solders are available for this alloy. I am
glad to know the alloy is available in findings such as solitaire
mountings and such. In a custom job, those findings do not help much.
I suggest you give Cobb a direct phone call and present the problems
you are having. I have found this old line company to be quite
willing in techinical assistance. Sure, they have in my opinion been
a bit slow in losing the "minimum purchase for reduced price"
reputation but this has been gone a while and Cobb simply has not let
the buyers know that!
Hoover and Strong has a white gold alloy which apparently also meets
the Euro standards on nickel. This company will also provide
techinical assistance as needed. Both Cobb and H&S are very reputable
and should provide any legitimate user with proper technical
If we get the reason and opportunity to use the Cobb "precise white"
alloy, I will post with our results.