Tips on bending rectangular wire

Dear Orchidians,

Please share your experience bending rectangular or flat wire (my
gremlin du jour). None of the books I have or an Orchid search
proved helpful. I have been making sterling rings banded (or
decked) with flat wire (instead of being in St. Petersburg. LOL).
The wire I am using ranges between .75mm to 2mm thick x 2.5 to 3.5
mm wide and decks each side of the ring. I am finding that when I go
thicker than 1mm the wire becomes difficult to work especially in
gold. It wants to bend flat rather than around. This is a similar
problem to reducing rectangular wire in a rolling mill. I have ring
bending pliers but usually have to anneal and flatten several times
before I get a good join and then I still have a good bit of filing
to do to clean up the marks left from the pliers (and I tape up my
pliers.) After I get the join and solder, rounding up on the mandrel
is another challenge. I usually pull the ring up the mandrel while
turning and hammering with a del-rin shot filled hammer while
carefully supporting the ring as I go and trying to hit just the top
of the wire but again the ring wants to bend flat. There’s probably
something obvious I am missing here. Any help would be greatly
appreciated.

Cheers
Bruce Raper
In Atlanta—where Spring is sprunging.