I actually tried normal masonry bits as well, I was through the glaze
with the masonry bit before I went out and bought a tile bit because I
wasn't making any progress. I didn't use hammer action knowing that I
would have been more likely to crack the tile.

I kept the bit constantly lubricated with water by sticking some
plastesine below the hole to form a cup and kept that topped up so the
bit didn't overheat + I was using a slow speed after experimenting
with different speeds to see what was working best.

I guess these are just very tough tiles...perhaps I should send the
remainder to NASA.

Ant.

"Dave Liquorice" wrote in message .1...
On 24 Nov 2003 05:39:33 -0800, ANt wrote:

I bought a Carbide tipped tile drill bit (Triangular little thing)
after breaking all my other bits on my bathroom tiles. With the
Carbide bit, it still took all my weight and a lot of sweet, some
blood and continuous drilling (800W Bosch Hammer / twin speed bla
bla) for 15 mins to put 1 hole through 1 tile.

I would have thought common sense would have told you that something
wasn't quite right after little or no impression after the first
minute.

How to drill a tile. Use a centre punch or similar to break the glaze
where you want the hole, the drill slowly with lubricant and no
hammer. Lubricant can be water sloshed or squirted on to the bit, keep
it wet at all times, not only does it wash out the "spoil" it also
cools the bit. Speed? 2 or 300 rpm max at a guess if the water starts
to spray even a little it's too fast.

After 15mins flat out what colour was the drill tip? Cherry red? Think
you'll almost certainly need a new bit... I've used the traditional
tile drill, flat pointed bit of carbide but last time I bought a
multipurpose drill anything from softwood to granite thing and it did
a pretty good job. I think it was Black 'n Decker branded possibly
"torpedo" it is very similar in apperance to an ordinary masonary
drill but has a little nipple at the centre.