small diameter diamond bits

[El Kabong!]

Hi,

I am working away slowly on my first ever entire bathroom refit.

All the tiling is finished, I am using procelain tiles.

I used a 25mm diamond bit to cut out 4 holes for the rad and shower pipes. I had to use 2 bits, but my method was a bit off on the first one and it didn't last too long.

I also used 12mm to cut two holes in the floor for securing the toilet pan.

I am now doing the smaller fixings... e.g the shower valve.

This needs 3 holes, and I got a 6mm bit. I managed to only get 1 hole out of it.

I am keeping the RPM low and keeping it wet and not using too much pressure.

The thing is that between the shower valve, shower screen and all the other fittings I will need to do, I can see myself spending 10-15 times 15quid per bit!!

Is there something I am missing? I should be getting about 10 holes per bit I would have thought?


Is it the case that the smaller diameter bits just don't last as there is literally less grit on them so it wears away?

Thanks.

 

[macten]

You can pick up small 6mm + 8mm diamond cores for under a quid on ebay. Smaller cores do wear quicker but you should be getting at least 10+ holes out of them though. Also a tungsten carbide tip drill bit should do the rest of your holes - I used to use Boschs' green and black ones from B+Q though I tend to just use diamond core drills as it works out cheaper and much quicker.
One tip for the shower screen fixings - sometimes the holes are predrilled or at least marked on the channel - don't bother with them and do your own to correspond with grout joints.

 

[El Kabong!]

Thanks.

My grout joints are 3mm so I guess I would have to partially drill thought the tiles anyway.

Are you saying that if I can find tungsten carbide tipped bits, that they should drill through the procelain too?

I will check out ebay and perhaps bulk buy some cheap ones! All I can find locally are the sets that have the water containers etc etc at about 15-25 a pop. I have textured tiles so the water containers never stay on anyway and just have a spray gun in my hand, so if I can just get some simple bits that would be OK....

 

[macten]

Best thing to do with the diamond ones is hold a wet sponge against the core as you're drilling.
Yes the drill bits will go through porc but will be more time consuming and a bit of a chore! you will have to keep it cool by dunking the tip in some water every so often. If you were to drill 6mm in a 3mm grout joint it will fly through it compared to going into the tile alone.

These are the type I used to use:

 

[macten]

Another tip if you are not fixing to timber and using rawl plugs - push them through the tile and into the hole you've created in the substrate. This removes the risk of the tile cracking as the plug expands when the screw is tightened.