It
is possible to cut a hole in a stainless steel sink. I've seen it
done, but it may be difficult. Stainless steel is extremely hard
and may resist the cutting actions of ordinary high-speed-steel
drill bits. But I'm not sure if a carbide-tipped bit would work.
If I were doing it, I'd try this:
- Get a 1/2" drill bit (you
can get them with a cut-down shank to fit in a 3/8 chuck). Plain
drill bits are high-speed steel. But I'd get a good-quality
name-brand bit, even if it cost $10 or more. Heat treating makes
all the difference and many off-brand drill bits seem to skip this
detail.
- Also get a high-quality
1/4" drill bit.
- Make a dimple with a center
punch (or a nail). This keeps the drill bit from wandering.
- First, drill a 1/4" hole.
- The trick to drilling steel is
using a slow drill speed (200 to 300 RPM) and pressing REALLY
HARD! (Two hands on the drill and all your weight bearing down.)
Most people just blast away at the drill's highest speed and push
faintly, but the bit simply skates over the surface, overheats and
gets dull.
- Lubricate the drilling action
with a light oil (WD-40 will suffice in a pinch, but I prefer
chain-and-cable lube). Oiling the cutting action will keep the
drill tip cool. When the oil smokes, you know to add more. Have a
helper spray oil on the drill every 10 seconds or so.
- Monitor the metal chips being
produced. In plain steel you can get a nice long spiral chip using
the method I describe above. But with stainless all you will
probably see is tiny flecks of metal. If you aren't getting some
chips, you need to slow down and press harder.
- But... when you finally break
through the metal, the drill bit will catch on a tang of steel and
possibly twist your wrist, break the bit (I've done that a lot) or
bend the sheet metal. So, when you know you are almost through
(and this is where experience comes into play) you need to speed
up the RPM, perhaps doubling, and not push too hard.
Yes this is a tricky procedure,
but I have seen it done (actually it was with a hole saw, which
was destroyed by the stainless steel's hardness). A small hole saw
might work, but, as described above, you really need to lubricate
the cutting with a light oil.
Another method would be to use a
Dremel Moto-Tool with an abrasive bit. Just make sure the sparks
don't ignite anything under the sink. I don't use my moto-tool
very much, but it is an excellent tool that everybody should have,
well worth the $60.
Bruce W. Maki, Editor.
