"Strom" wrote in message
...
On Mon, 17 Nov 2003 09:21:30 +0000, "John Hearns"
wrote:

I guess this is asked a lot, so please point
me in the right direction.

I want to drill some holes in large bathroom tiles,
to take screws for a grab bar in a shower.

I've been advised to buy a drill bit specific to this task -
what should I ask for, and what is different about these bits?
I'll be visiting South London Power Tools, which seems to have
a great range of these types of things. I'd like to display
some knowledge of what I'm after though!

Also, what sort of wall anchors are recommended?
The tiles are on the side of a shower stall, which is probably
made of plasterboard underneath.
I've got some spring toggles and some other expaning wall anchors.
Use a new masonary drill push the drill onto the tile until you hear a
crispy noise then you can drill your hole very slowly.Spring toggles
are ok but I use umbrella clips same principal but when you take the
bolt out the base stays in the wall without falling out.T.R.



A slightly better way. Use a thick black fibre-tip to put a mark where you
want to drill the hole. Then use something like a tungston-carbide tipped
scribing tool and crack/craze the glaze where you want the hole. Re-mark the
hole and put some masking tape over it. You should be able to see the mark
through the tape which you can then repeat the mark on top of the tape.
Finally drill the hole with a masonary drill NOT in hammer mode - and as
slowly (at first at least) as the drilling machine will go. The mark will
allow you to get the exact point where you have crazed the glaze and the
tape will stop the drill sliding.Once you are established in the tile
increase the speed but DO NOT apply pressure or you will crack the tile. It
sometimes helps, dependent upon tile type and construction, if you wet the
drill tip as you go - it also cools the drill bit.


--
Woody