One of the wonderful things about being a metalsmith is that you can
make whatever tool you need.
Handheld drill not strong enough to twist the wire you you need to
twist? No problem! Make something that will twist it.
Case in point: I don’t think I’d fuss with a hand drill as a twister
for anything much heavier than 2 strands of 14 gauge wire.
That doesn’t mean I don’t twist heavier things, just that I don’t do
it with a drill.
I’ve got a twisted wire bracelet that I do with beginners that’s two
strands of 6ga nickel silver twisted together, sometimes with
another pair of twisted brass or copper wires threaded into the
gaps, so sometimes it’s two 6ga nickel silvers, plus 2 roughly 12ga
brass wires. No way on earth a hand drill is going to shift that.
But a screwdriver does just fine.
Take your wire, double it over, and then clamp the loose end in a
vise, just as you would for twisting with a drill.
Then go find the biggest phillips (cross) head screwdriver you can
find. The one I used was about a foot long, and about 1/4" thick.
The reason for the phillips head was that the head doesn’t get
thicker than the body. Failing a big screwdriver, a foot long chunk
of simple round steel bar will work just fine. The important part is
that the ends not be bigger than the middle.
Stick the bar into the loop in the end of the wire, pull back away
from the vise, and start twisting. It’ll be slow, but that’s not
really a big deal. Stop twisting when you like the twist. The
important part is to keep pulling on it, to keep it taught.
Otherwise it’ll kink.
When you’re done, just pull the rod out, and you’re good. The end
loop will have clamped down on it, which is why it’s important that
the ends not be bigger than the middle.
Hope that helped.