Drilling tiles

[TD]

I just want to put a towel rail up but I'm getting nowhere fast. My bathroom has very hard porcelain tiles, glazed. I'm using a bit like this

I was told is suitable for porcelain (and glass). Not sure what the material is, don't think it's diamond-tipped. But I've made little progress even after breaking the glaze.

Is it possible that I've overheated the bit? What speed should I use these bits at, and is it necessary to spray them with water? I think I started slowly, not much happened so I lost patience and sped up.

Is this a job that a decent (not crap, not the best) cordless drill driver should be able to achieve? I've been using the mains drill, but if I need to slow down, I get better control with the cordless.

[Dave Plowman (News)]

which I was told is suitable for porcelain (and glass). Not sure what

I have similar tiles, and the best I found by far is a diamond coated 'drum' - the diameter of the hole needed. Much more expensive than the ones you've showed but does work, albeit slowly, and what's more did all the holes I needed, which were many. You do need to stop and dip it in water frequently - so a battery drill is obviously the best choice. And one which runs slowly. Can't remember the brand, but may have been DeWalt. It works by grinding, rather than cutting, the hole.

[Bill Wright]

I've found the best thing is a standard SDS bit used without hammer action. I have to drill tiles quite often in order to fit TV sockets in kitchens. I put a bit of masking tape over the place where I'm going to drill to prevent skating then apply the drill without much pressure and just wait. For a while it seems as if it isn't going to work but then it sort of digs in a bit and starts to drill. The risk if you press on is that the tile will break. If the drill snags it will break the tile, so go steady.

If you are using wall plugs, cut the rim off the head so you can poke the whole plug through the hole. You don't want the top of the plug expanding when you put the screw in because it would break the tile. Make sure the hole is significantly wider than the screw, and be careful the screw doesn't get forced sideways against the edge of the hole in the tile. It needs clearance all round.

If the towel rail doesn't have rubber feet make some (old innertube), because otherwise you won't be able to get it tight enough without risking it pressing on the tile in a small area and breaking it.

Bill

[Dave Plowman (News)]

Have you tried this on porcelain tiles? With ordinary wall tiles just about any drill will work.

[stuart noble]

The problems with drilling, and the speed of cutting them, would certainly put me off ever buying porcelain tiles. Are there benefits to these things? They look the same as ceramic to me but maybe I haven't looked closely enough

[TD]

Exactly. Does anyone know whether I was somehow using the bit improperly, as I asked in my first post? Dave, I'm sure your "diamond drum" bits are great, but I'd like to know if I can get by with what I have. It's a 3-pack, 2 of which won't get used until I find out if a) I might have ruined the first one by drilling too fast without water or b) they just aren't up to the job.

[Dave Plowman (News)]

Basically, they are a lot stronger than ordinary tiles. So more likely to be found as a floor tile. But also as larger wall tiles.

[Dave Plowman (News)]

Difficult to answer. It would depend on the quality of the tip. The one I bought - from B&Q, and a decent 'name' was pretty useless. I was using a very slow speed.

[John Sabine]

TD, like Dave says above, for porcelain tiles you're almost certain to need a specialist bit - the ones linked to in the first post will be fine for ceramic, but if you've written off one of them already, I wouldn't bother trying with the others.

Looking at

I think I've seen the DeWalt bit branded as BOA (at least it comes with the same cooling attachment in a fetching orange), and found them very good; the cheap diamond bit at the bottom of the page looks like ones I've got from elsewhere and found adequate for a few holes, but worn out after a bit of use, possibly because I'm impatient and was using too high a speed.

No idea about the Bosch Expert one though if I needed a new bit I'd be tempted to try it: the Marcrist ones are clearly silly expensive for domestic use.

-- John

[F Murtz]

I build a dam of putty and fill with kero or turps when drilling glass but you can't on vertical tiles

[Andy Dingley]

IMHE,the best way to drill porcelain tiles is to drill them before tiling, = in a bench drill, with a pond of white spirit lubricant too.

Then when you put them up, laser across from one (drilled, stuck on the wal= l) to the other (loosely held in place) to mark it, before drilling that on= e.

If it's off-site, then drill both beforehand, but be careful of your levels= when setting them in place.

If you have spare tiles now, practice drilling a couple to get a feel for s= peeds and pressures. Those leaf bits do take some pressure, but they're als= o near-impossible to overheat. I have though found a lot of quality differ= ence in their sharpness. Some of them (even from Axminster) just weren't sh= arp. Some work with a diamond hone made them require far less pressure afte= rwards.

[Dave Plowman (News)]

The DeWalt one shown in the pic is the one I have. I know 20 quid is a lot, but since it does what it is meant to and you have the usual number of bathroom fittings, it really is worth it.

[Dave Plowman (News)]

Crikey. You must be a good planner. ;-)

[Andy Dingley]

Vaseline. Saves all that hassle when it fails to stick to the tile after yo= u fill it with turps.

You can, but it's a pain.

Find a plastic bottle and turn it into short plastic pipe with a 45* end an= d a little hole for the drill bit. Silicone it to the wall. Have an assista= nt with a chem lab wash bottle of turps squirt it slowly from above. Collec= t the runoff in the pipe. Afterwards peel it away from above and tip it ba= ckwards to drain.

[Andy Dingley]

Dead easy, if you're walking distance of the workshop.

Harder if you're off-site, as you have to mark both and then hope that your tile setting is accurate afterwards (If it isn't, buy a laser cross level - marvellous things for tiling).

[John Rumm]

which I was told is suitable for porcelain (and glass). Not sure what the

Those bits are not really up to hard tiles....

Armeg (and probably others) make some tile drills with solid carbide tips. However even these need careful handling[1], are slow, and will only do 20 holes per bit on the hardest tiles.

You can also get some diamond grit edged holesaws which work well in hard tiles[2] - again slow progress, and need cooling.

The last time I needed to do anything on really hard tiles, I found it easier to do as much as possible with a small angle grinder and a posh Norton continuous edge hard material disc (the disk cost more than the grinder!) In many cases, one could cut a slot for a couple of screw holes and have whatever you are fixing cover it up.

[1] High pressure (250N), slow rotation (700 - 900 rpm), and continous water spray cooling. [2] Is this a job that a decent (not crap, not the best) cordless drill driver

Either a cordless drill, or a mains SDS (on rotation only) will give about the right speed. With the carbide bits you can be waiting 15 mins a hole!

[John Rumm]

If they really are properly hard porcelain, then not a chance I am afraid.

However to do the next, keep to moderate speeds (cordless in low gear at full throttle would be about right) and keep spraying with water. Plenty of push as well.