On 04/04/2012 10:53, Rod Speed wrote:
stuart noble wrote:
On 04/04/2012 10:30, Martin Brown wrote:
On 03/04/2012 21:26, Chris Holford wrote:
In ,
Fredfred@no- email.here.invalid writes
On Sun, 1 Apr 2012 09:34:05 +0100, Chris Holford
wrote:

I've tried a plunger, and tried
neutralising with spirits of salts

Still waiting for the NaOH to dissolve!

Does water drain away at all? If so your only remaining option is to
risk adding very hot water and hope that it will solvate the caustic.
Repeat hourly until the thing runs free again.

Wear eye protection and if possible a full face shield.

Otherwise you are down to a dismantling job. Next time make up the
solution carefully from the solid and pour it down the plug hole!
(again eye protection essential it gets pretty hot when dissolving)

I reckon most people are better off with one of the proprietory drain
cleaners since it avoids pitfalls like this one with overdose of the
solid causing a worse problem than the fault it was trying to fix.


I've never known it take this long to dissolve, even when it has
formed a solid lump. I used to have a tank of the stuff so I know a
little about its behaviour.

He did however attempt to neutralise it with HCl, so its
almost certainly the resulting NaCl thats not dissolving now
so your experience isnt that relevant to the rate it dissolves at.


But it has to have dissolved in order to be neutralised. Otherwise the
acid would at least partially wash over it