As no one seems to have answered your posting, ill chip in here and
say a few words.
In all your experience, havnt you ever heard of running an
experiment?, or a trial before doing the real thing? How many times
did you have to try and get your soldering right? So, ill point you
in the right direction. Make a leaf, gild it, barrel it and see what
If it works ok then you can judge if its safe to barrel the bangle.
If not then have you heard what a glove does? it protects your hands
from what ever. So why not mask your gold with whatever prior to
barrelling? Next, If youve designed a bangle that needs bending to
put on the design is wrong.
Sorry to be hard but sometimes its the only way to get through to
other metal workers what it takes to get it right.
Update us how your test works out