[Enamel Bits] Flux contamination of the enamel

Dear Enamal Experts, I have run into 2 problems.The first is firescale and
enamal creep while trying to repair"Hawaiian Heirloom Jewelry"( you know
the black enamal Old English letters cut into gold with the hand engraved
backgrounds). Is there somekind of flux that won’t contaminate the enamal
and can be taken off without using pickle, which attacks the finish of the
enamal . So far, I only know to sand off all the fire scale and excess
enamal, then polish and reengrave, but yiikes that is tedious. The second
is pitting of the final firing, even though the pre-fired surface looks
good.( I am torch firing the enamal) So far no customers have complained,
but it bugs me nevertheless. Thank You John Caro Jewelry By Design Woodbridge,