Phil Addison wrote:

re drilling faq

Nice job, lots of info. I always like to be a pain, so could offer a
few more snippets to think about:


another way to avoid dust is to tie your hoover hose to the depth stop
on the drill. Although its a bit to the side, the air suction takes
care of that no problem. I've saved endless work that way, makes a big
difference.

If it were my faq I might replace 'very hot' with red hot, in case
folks may not realise just how seriously hot they can go. I've had bits
go red hot in the days before hammer drills.

Driling laminates eg formica tends to produce a messy hole. Pressing a
piece of hardboard over it and drilling through that makes a big
difference. (Same with sawing the stuff.) Downward pressure must be
maintained while drilling, a clamp is often the easy way.

I've always found standard twist drills do soft metals acceptably as
long as one goes real easy on pressure. The angle is too aggressive,
but using less pressure counters this fairly well, preventing gouging
and binding. Breaking through is best done by holding the chuck and
turning it by hand, problems are likely if you try and power through.

Lip and spur bits: these drill wood faster and with less effort than
standard twist, so are recommended for codless use. And really for most
wood drilling use.

You say flat bits drill clean holes: how? whenever I've used them
theyve been pretty msesy. One advantage of a flat bit is that if youre
caught without the right size bit you can use a hammer to make one out
of anything rodlike.

Auger bits need high torque and very low drill speed. Theyre barely
suitable for mains drills.

All drill bits should be removed from an unfinished hole while being
spun clockwise, except for augers, and expcet when it has dug right in
and wont turn.

"Then there are those you find in DIY sheds. these are thin bendy
spring steel things that do not quite form a complete circle, and you
get a whole set of them mounted on a single wide arbour.These thin
floppy ones can cut holes through sheet materials, though not much
else. The arbour is always bigger than the cutter so you can drill no
deeper than the exposed depth of the blade. The set comes with all the
blades mounted on the arbour, but in use they should all be removed
except the one required, remembering to do the securing grub-screw up
tight"

I can add that these must be used with much gentleness and patience, as
applying even mild to normal driling pressure is enough to ruin them
immediately, and damage the workpiece. They are a very weak cheapskate
option. I know this from experience. Theyre ideal where few holes are
ever needed, as theyre slow, weak, likely to be short lived, but very
cheap. There must be a proper name for these?

decent from a ladder - descent from a ladder

Sanding discs: use a light stroking action to avoid gauges. Once you
get the hang of it its quite prctical to sand large quantities of wood
this way. But if you dont get the hang of it, I hope you like crescent
shapes!

"How do I stop my drill-bit from slipping in the chuck?"
easy, use less pressure.

"Cutting off the last foot of cable and rewiring the drill could save
you the price of a new drill (do unplug it first!)"

yes, but this tends to happen at both ends. If one end has gone, the
other end will most likely be in an unsafe state, so the same trick
should be done both ends.

I notice you didnt mntion hex shank drills. I use these a lot, theyre a
real time and energy saver because the bits can be swapped over by just
pulling it out and pushing the new one in. A hex adaptor for the drill
is a real time saver. The downsides a
- high torque must be avoided, since the bit is liable to come unstuck
from the hex base
- the bits cost more than round twist drills, but theyre well worth it.
- they tend to wobble a bit, which can be an issue in a minority of
situations.

With hex shank I'd recommend titanium coated ones. Ti coating is a
great thing anyway, plus it reduces the required torque.


thanks for the work,
NT