aluminum rib, aluminum spar, holes drilled but screws broken off

wright1902glider wrote:
You might also try a left-hand (that is the reverse of standard,
right?) drill bit. HF sells 'em, and you may also find them packaged
with a set of EZ-outs at the BLUE or ORANGE stores. That might work if
the screws aren't corroded into the holes. If there's enough of a screw
left, I've also had mixed results filing flats on the screws 180
degrees opposed, and grabbing on with a crescent wrench or vice-grips.
Careful, don't break the screw off a second time like I did.

You might also try drilling with cutting fluid. I had a similar
experience trying to drill out a set of rivets holding the ball joints
into my Dodge. (Wadda they make those damn rivets out of anyway?) With
the hand-electric drill it took 27 broken bits and 4 days. When I did
the other side, I pulled the a-arm out of the truck, mounted in a vise
on the drill press, and then drilled down using a 1/64" cobalt bit and
cutting fluid. It only took about 5 minutes per hole using 7 different
sized bits to achieve the same results. I wasn't using any more
pressure or speed with the drill press. So maybe the cutting fluid is a
semi-magic bullet?



Excellent advice, there Wright 1902. Thanks a lot. I'll run to the
HF store and see what I can find. Something's gotta work.