fitting strainer waste to existing SS sink

[cadular]

I want to fit a 3,5" strainer type waste to my existing sink, which means I have to cut a larger hole.

How can I do this, and what tool will I need please

 

[jmower]

I'm sure if you search some trade suppliers you may be able to find some sort of high TPI hole saw (roughly the same TPI as a junior (12-14?), Dont hold me too it but I think I have see one before, but using it didnt go exactly to plan.

Good luck on your quest! remember if all else fails buy a new sink!

 

[TicklyT]

Will there be a flat recessed 'land' left around the hole so the waste won't sit proud of the bottom of the sink, stopping the bowl from draining completely?

You would need to plug the existing waste hole to support the pilot bit of a hole saw.

Beware of a hole saw snagging, and twisting the stainless (or your wrists!) when it breaks through. A friend lost the end of a finger when a hole saw snagged, and the drill turned round and bit him

Maybe accurate marking out, and a fine metal cutting blade in a jigsaw would do it.

I would favour something more like a Q-Max hole punch as the nicest way to do it, but an 80mm one would probably set you back about £50 or so .

 

[cadular]

The existing sink drain 1.5" is set into a saucer like depression, which is 4.75" maximum across, which seems to suggest that it is capable of taking the larger drain size, without water not draining away.

I think Q-max cutter would be the best and safest option, but where would I buy or preferably hire one.

Regards

Cadular.

 

[bwallum]

I have just done that job and opened up the existing sink outlet with a 120mm angle grinder by cutting a series of slots then tidying up the rough edge. I used a file to de-burr the underside. The strainer waste fits perfectly and looks as though it was always meant to be there with no ponding whatsoever. The strainer waste was an Astracast with a vertical 40mm outlet. It came with a thin top compressible washer and a thick bottom rubber like washer.

If you want to be really tidy use a waste with a horizontal outlet and a hepvo 40mm waste seal...end of dangling traps and more cupboard room.