Any tips on unblocking sink -- desperate, it's nearly teatime

[bakedpotato]

A plumber had agreed to come, but his mobile is now switched off and he's 20 mins late so is obv starting w/e early.
I've tried caustic soda, plunging, run out of ideas

[happymerryberries]

Boiling water, which helps to melt any greasy gunk

[bakedpotato]

the sink is 3/4 full of black water and smells rank from the caustic soda
am scared of blowing house up if i put anything else in, do you think i should be rash and chance it?

[bakedpotato]

no room for the boiling water

[happymerryberries]

syphon some of the water out

[kid]

How about using a pot or bowl to empty some of the water from the sink first. I know I'd rather get rid of most of the water than risk it overflowing!

Then pour boiling water in to see if that helps?

[happymerryberries]

Don't add any more chemicals to the caustic soda. very important that you don't add bleach

[happymerryberries]

www.diynot.com/pages/pl/pl005.php

Migh give you some ideas

[bakedpotato]

oh Dinosaur so kind, does he travel to N London?
Mind you no plumber is going to come out at this time of day on a friday
Thank you HMB for chemical advice
would like to know why this sort of thing always happens late on fri afternoon

[bakedpotato]

(whoops, plumber may be a she of course )

instead of typing 'wink' i just typed 'sink'