It seems like I have no mercy on my my files and drill
bits- but i can not figure out what I am doing wrong.
G’day DD: this begs a few questions; what sized drills are we
talking about? What machine do you use? Are the drills old or
new? You should be able to feel the sharp edge on a drill.
Compare it with a brand new one. Like everything else, when
someone has shown you how, drill sharpening is not difficult. But
you have to be SHOWN - you can’t learn the technique from a
description - at least I couldn’t. Just holding the conical edge
against a spinning stone and rotating the drill on it’s axis
won’t work. You can buy drill sharpening jigs in tool and
hardware shops, though I’ve never used one so don’t know how
good they are. Preferably get a workshop technician to
demonstrate drill sharpening. Wish I wasn’t so far away!
Next, the drill must rotate clockwise. No, don’t laugh - I
witnessed just that a week ago - I didn’t even see what was wrong
at first! and the person ruined the drill edges in a moment or
two. It must spin clockwise into the work piece.
Thirdly, the rules are; the softer the work the faster the drill
speed. But not too fast. For wood; very fast. For steel, slow.
Then the smaller the drill, the faster the speed. But again not
too fast - or you’ll overheat and soften the cutting edges.
Drilling gold and silver I never spin the drill faster than about
3000rpm, not even with drills smaller than one millimetre.
Whereas even the cheap handpieces can spin at 15 - 20 000 rpm at
full speed. I find drills don’t cut at that speed on metals. Use
a little saliva as lubricant for gold and silver - it works well,
believe me. WD40 or CRC556 for aluminium, soft brass and mild
steel. I find Oil is useless.
Am I pushing down to hard - or not enough?.
It depends on what you’re drilling. Try and let the drill bit do
the work, but that said, use enough pressure to engage the work
properly. Lift the drill frequently to clear the swarf from the
Also, my best files are not at their best. I have a file
brush but it does not seem to clean my files well (which
direction are you suppose to use the file brush anyway?)
Files do wear out after a bit, and they also clog easily on soft
materials. If you use a wire brush or file card, brush in the
direction of the grooves in the file. To avoid that clogging -
especially on aluminium and fine silver to a lesser extent - give
the file a quick squirt of WD40 or CRC556 before starting; I’ve
not found anything to beat this yet. The older engineers used to
chalk their files, but these modern lubricants are far better;
they stop the swarf jamming into the grooves.
Also, I always file properly (away from me instead of towards
me-learned proper filing techniques at Revere)
Never file back and forth; lift the file at the end of each
forward stroke for the return.
Also, my best coolest file from Germany has a bit of rust
Again, use the trusty WD40 or CRC556 after use to stop them going
What is the best way to clean up the rust and bring my >
file some what back to peak condition?
Soak for a short while in commercial rust remover from the
hardware or paint store; it contains phosphoric acid. Can be
re-used. Or Coca Cola which also contains phosphoric acid (!!!)
Wash and dry well, then the WD40- etc treatment.
I’ll bet there’ll be a dozen more pieces of advice! But cheers
/\ John Burgess
/ / Johnb@ts.co.nz
(_______) Mapua NZ is a pleasant spot even in midwinter
(-4C last night! 12C yesterday, cloudless sunshine)