Soldering Sterling to Fine Silver Before Enamel

Hello All: I have been having a heck of a time soldering a U-shape 18
gauge Sterling hinge onto 22 gauge fine silver pin (about 2" circle).
I am using IT because it will be enameled. If anyone has a suggestion
on how to accomplish this in less than the two days it has taken me
to perfect the process, I would love to give it a try. I have always
cleaned and prepared both pieces. Fluxed (Handy Flux or Batterns),
dried, fluxed IT when positioned. Tried to solder on charcoal, on
honeycomb, on tripod. Know to heat larger pin area, not too much the
sterling which is adjacent. Have seen it flow a few times for sure,
only to have it separate in the pickle which I put it into after a
cooling period. When I tried the tripod, I domed the screen to cradle
the piece. The screen left markings on the front, and I was going to
be using transparents. Am not sure what the rust colored marks are
but will use this piece for practice and opaques mainly. Any and all
help greatly appreciated. Thank you. Cindy Brucksch Deepwater, MO