How do I undo this waste nut, which is in a tight spot?

[dilalio]

If the silicone is old enough (or cheap enough), just twist the waste and it will come off.

Twist the basin not the waste.

 

[johnny2007]

Twist the basin not the waste.

Yes, you're right.
Same as when unscrewing a light bulb, twist the ceiling, not the bulb.

 

[dilalio]

Yes, you're right.
Same as when unscrewing a light bulb, twist the ceiling, not the bulb.

Nothing like that.

Why would you twist the waste to break the seal between the basin and worktop?

Otherwise know as the fulcrum and the pivot!

 

[johnny2007]

Nothing like that.

Why would you twist the waste to break the seal between the basin and worktop?

Otherwise know as the fulcrum and the pivot!

Sorry, I forgot to state the obvious.
Remove the basin, then, and only then, remove the waste nut and after this, twist the waste to break the silicone seal.
My apologies.

 

[dilalio]

Sorry, I forgot to state the obvious.
Remove the basin, then, and only then, remove the waste nut and after this, twist the waste to break the silicone seal.
My apologies.

That's if the waste has been siliconed in and not done using plumbers mait, which is my preferred method.

 

[johnny2007]

That's if the waste has been siliconed in and not done using plumbers mait, which is my preferred method.

Why would that matter?
The waste is attached to the basin (the white ceramic thing that people use to wash their hands), not the worktop.
It doesn't matter what you twist, basin or waste, it's a matter of relativity.

 

[dilalio]

Why would that matter?
The waste is attached to the basin (the white ceramic thing that people use to wash their hands), not the worktop.
It doesn't matter what you twist, basin or waste, it's a matter of relativity.

You really aren't getting it!

The basin is 'usually' secured to the unit using a bead of silicone around the bottom edge. Hopefully, some clown hasn't used a whole tube of it, at the base... That's why I suggested a cutting wire (for that scenario).

The waste is secured to the basin using the nut and washers supplied. Best to discard the uppermost washer and use a brass backnut (as mentioned above) and either silicone or mait, both sides of the throat of the basin to make it watertight!

So... To remove basin from unit, twist it CW then CCW a few times, to see if it will give. If not, use the cutting wire.

Then... To remove the waste from basin, use same twisting action by holding neck of waste (with gloves on as they are sharp threads), if that fails use a pair of grips, tap it with a hammer, cut silicone with blade. If it's mait, it will come out easily and will be easier to clean up the throat of the basin.

Is that clear enough?

@Beverly27 check your new waste is unslotted

 

[johnny2007]

We were talking about removing the waste from the basin.

 

[dilalio]

We were talking about removing the waste from the basin.

Last I looked it was about removing the basin from the unit!

 

[Beverly27]

So, we've hit a quite literal sticking point. The sink won't release from the granite countertop and can't be turned clockwise or counterclockwise, even after the use of cutting wire, which we haven't been able to move completely under the sink, because I suspect that there is an inordinate amount of cured silicone sealant there. I'm loathe to use a hammer to try to tap in the Harris filling knife that has a very thin blade and so I don't know what the hell to do next to try to remove this damn sink from the worktop. I've tried spraying WD-40 and pure alcohol on the sealant to little effect. Any other suggestions here please guys? Oh and the new waste is unslotted, if we can ever fit it!

 

[dilalio]

Oh dear! Hope it hasn't been stuck down with gripfill or something like that!

How thin is your cutting wire? Does it have handles?

 

[kidgreen61]

As this is tricky to access, I would heat a chisel to red heat, and push it against plastic nut to melt it, job done.

 

[conny]

As this is tricky to access, I would heat a chisel to red heat, and push it against plastic nut to melt it, job done.

Even if that worked and she got the nut off she then has to fit the new nut, which would involve buying another tool.
@Beverly27 as you work round with the cutting wire try to slip some thin steel washers under the basin. It may be that as you cut and then move round the silicone is re-sealing. Bear in mind you won't be able to cut right through from front to back because the waste, (and possibly tap), pipe will be in the way. You always use a few butter knife blades if you don't have any washers. The aim is to stop the sink sitting back down on the cut silicone and re-sealing.

 

[Beverly27]

Oh dear! Hope it hasn't been stuck down with gripfill or something like that!

How thin is your cutting wire? Does it have handles?

I suspect gripfill may have been used dilalio! We're now using a guitar string because the cutting wire was too thick and improvising with pencils as handles, until some arrive on Saturday! To be fair, I did manage to get a little clockwise and counter-clockwise movement this morning. I had wondered if using our heat gun might help.

 

[Beverly27]

Even if that worked and she got the nut off she then has to fit the new nut, which would involve buying another tool.
@Beverly27 as you work round with the cutting wire try to slip some thin steel washers under the basin. It may be that as you cut and then move round the silicone is re-sealing. Bear in mind you won't be able to cut right through from front to back because the waste, (and possibly tap), pipe will be in the way. You always use a few butter knife blades if you don't have any washers. The aim is to stop the sink sitting back down on the cut silicone and re-sealing.

Thank you Conny, I'm now determined to do this! I'll buy some thin steel washers this weekend, although I don't think that I've cut far enough under the sink to need them just yet, but it can't hurt to try!