drilling hole in tile cracks my tile!

[finest1]

hi all

i need some help and advice

i am tiling around 2 shower pipe fittings. as the measurements were intricate i was practicing on off cuts and trying to create a template. I've noticed when i drill holes into the tiles sometimes they would crack. i don't use any pressure or drill too fast. anyway, the good news is that i have created the template down to the mm. however when creating the template a bit cracked. when i go on to making the holes on the proper tile i don't want that to crack, as i'm running out of tiles. why is it cracking and what can i do to prevent it

method: in this instance, i used my workmate bench and clamped it with G clamps around the tile. i clamped them enough to hold the tile steady, as opposed to over tightening the clamps.


thanks in advance

finest1

[dewaltdisney]

You need a tile bit that looks like an arrow head. This pierces the ceramic and goes through to the bisque core. It is a slow gradual process using smaller bits and going through with larger bits to the desired diameter. I find a blipping action at a slower drill speed is best.

DWD

[finest1]

hi Dewalt

thanks for your response. i used a 15mm diamond hole saw. i used a slow speed to penetrate the glazing. to be fair it didn't take much to break the glazing and start drilling. i just don't know at what point it cracked. i do have one of those drill bits with the arrow head you mentioned. are you advising to drill that first in the centre of the hole, then use the hole saw?

[dewaltdisney]

It is often vibration and pressure that causes the crack. Hole saws are a bit hit and miss and I prefer progressive drill sizes as slower drilling tends to be best

DWD

[toolbox]

I would suggest laying the tile on some thick cardboard get someone to hold it do not clamp place the spot to be drilled over a hole, the peg holes in a workmate are ideal, or some ply.
As said slow and easy does the trick. Holesaw should be fine.

[finest1]

I would suggest laying the tile on some thick cardboard get someone to hold it do not clamp place the spot to be drilled over a hole, the peg holes in a workmate are ideal, or some ply.
As said slow and easy does the trick. Holesaw should be fine.

i take it i need to try to absorb some of the vibrations, as the the tile was on hard surface (work bench) with the template clamped to it

[toolbox]

Yes tape the template to the tile.

[finest1]

how do i keep the whole lot steady if i can't clamp it? just use the vice on the work mate?

[toolbox]

If you feel you cannot hold it still, also tape it to the workmate. Or use a bit of ply/ mdf to spread the load of a clamp. But I would have thought an assistant wearing gloves would be able to hold it steady enough to stop it spinning.

[finest1]

hi all, thanks for your tips. i drilled the holes successfully.

if anyone reads this in the future, i did the following:

i used duct tape to tape the tiles together,
i rested the tile on a a damp to wet dishtowel, and rested the whole lot on ply wood
i then taped the whole thing to the workbench
i used a slow speed to cut into the tile. its hard to explain what slow was, but i did it by feel. it wasn't high speed drilling but a constant but medium speed. it basically took time to do. i didn't time it but it was definitely minimum 15 minutes. probably over kill but i didn't want to risk another cracked tile
i was constantly dropping cold water into the hole to keep the drill bit from heating
use patience and resist speeding up the drill!! that was the hard part,

result: perfectly measured and cut tile

thanks

[Someone-Else]

result: perfectly measured and cut tile