Ceramic sink tap knockout

[Phil]

I fitted my first white ceramic sink the other day or it may have been porcelain and it required me to use a 10mm centre punch and chip my way through for tap hole, the hole came out jagged and not in one round piece like the knockout.
I didn't fancy drilling it as if the cutter slipped when bitting in I would have have to buy a new sink (£180). And drilling from the underside may have caused breakout.

Just didn't seem right as I had to really whack it hard to get through.

Not sure I'll be doing another, has anyone ever cracked one?

 

[Riley]

No you just have to go balls out and give it a firm whack. I know it’s against all your better instincts

 

[Burger]

Not too much welly though

 

[Aire]

Done quite a few of the Franke ones, always concerns me but never had an issue with one breaking.

 

[oz-plumber]

We had about 30 to do in an apartment block.
We felt much safer and more brutal after the first 10.

 

[Phil]

It feels so wrong on ceramic, its like getting a toilet cistern lid and just bashing a hole out with a centre punch and hammer. Its probably the case that the hole is drilled to such a depth that it will never crack beyond the hole but I did get a large chip around the edge which the tap body only just covered.

 

[Best]

Ball peen hammer they say is the best for that.
I don’t like doing it.
Best left to the kitchen fitters to take the grief.

 

[Stu-B]

Did a howdens one last week, drilled it with a diamond tipped 6mm bit from underneath a few times first...
yes I am a scaredy-cat

 

[Riley]

Coward

 

[Rob Foster]

A small ball peen hammer working out from a central hole is best and use some gaffer tape or insulation tape on top of the ceramic to help cushion the blows and help keep the glaze intact. Wickle taps gently working round and outwards is the way. Done some really expensive Italian stuff over the years certainly gets the adrenaline going..Rob Foster

 

[Riley]

Why a dislike Rob?? I’m not wrong?

 

[Rob Foster]

Why a dislike Rob?? I’m not wrong?

In my opinion gently does it with a ball peen not all knock outs have a thin glaze and if you are going to do the combination basins which give you a choice of 1 or two either side a big bash can take the lot out...saw this once at the initial re furb of the Theatre Royal in Bath in 1982 ish ...not moi that guy was mortified ..
denso is quite good as a shock absorber
no criticism of you just my point of view
Rob Foster aka centralheatking

 

[Rob Foster]

Did a howdens one last week, drilled it with a diamond tipped 6mm bit from underneath a few times first...
yes I am a scaredy-cat

quite right some of these designer ones are worth a fortune esp the Italian ones
chking

 

[tomplumb83]

Few years ago, i'm there doing the plumbing for my dad's new kitchen.
Reluctantly tapping away at the ceramic sink and getting nowhere
The fitter tells me he'll do it. One wack and he smashed the thing. He was going to pay for the lot but my dad went half with him
I won't fit them unless the hole has been cut out

 

[toucan]

I fitted my first white ceramic sink the other day or it may have been porcelain and it required me to use a 10mm centre punch and chip my way through for tap hole, the hole came out jagged and not in one round piece like the knockout.
I didn't fancy drilling it as if the cutter slipped when bitting in I would have have to buy a new sink (£180). And drilling from the underside may have caused breakout.

Just didn't seem right as I had to really whack it hard to get through.

Not sure I'll be doing another, has anyone ever cracked one?

I use hole saw with thin ply template