caustic soda for blockage

paddypaws101

Rental property...tenants report that kitchen sink has been emptying slowly and now nearly over flowed when washing machine was on. I did buy them some 'One Shot' cleaner (sulphuric acid I think ) which they say they have used without improvement. water is clearing but slowly so not completely blocked.
I now plan to try caustic soda myself...will wear gloves and goggles! My question is...hot or cold water?
I have always tipped the crystals down the sink then followed with a kettle of boiling water but I have recently read only to use cold water.
It does bubble up with the hot water, but has always cleared any blockage! I have also read that adding cold water sets the soda solid and don't want that.
Advice?

yoyoegg

IMHO caustic soda is less aggressive in its action than an acid for clearing blockages.

If you want to push the limits, get 'spirit of salts' (hydrochloric acid) and stand well back...

maintenanceman

Whooaa with the acid!! Before you star chucking acis down there you might have to take a more practical rout. Have you tried unscrewing th trap under the sink. You might also find that the waste from the washing machine has blocked the trap. remember that anything you unscrew down there will over flow so put suitable containers under sink trap.

paddypaws101

I think the tenants did say they had tried emptying the u-bend under the sink already. I can of course check that again myself first.
After that....Hot or Cold water with the Soda???

maintenanceman

can't answer that question whether hot or cold water with caustic soda cos I don't use it. Check the trap first or follow the instruction with the caustic soda if you are determined to use it. Good Luck.

consumers_revenge

Its probably further down the pipe....

Seriously we tried every acid/organic/mr muscle/plunger and in the end your likely to be wasting your time if its a heavy duty blockage.

Just do yourself a favour. Bnq http://www.diy.com/nav/fix/plumbing/plumbing-supplies/waste___overflows/Tools-4-Spring-Spiral-Drain-Cleaner-T605Q-9271717?skuId=9281417 bend the thin end of the snake slightly feed it as far down your tubes as it will go. Put the other end in a drill and slowly start it turning. Be gone in 3 mins! and nowhere near as dangerous as acid.

I wont think twice about doing this in the future....

booter

maintenanceman wrote: »

Whooaa with the acid!! Before you star chucking acis down there you might have to take a more practical rout. Have you tried unscrewing th trap under the sink. You might also find that the waste from the washing machine has blocked the trap. remember that anything you unscrew down there will over flow so put suitable containers under sink trap.

Completely agree! When my kitchen sink starts to empty slowly, my first port of call is the outside drain. If that's "furred up" with fat/hair/leaves etc, then that will sometimes cause the slow drainage. So, I clear that first, then have a look at the trap, and only then, if all else has failed, will I use caustic soda. But if the one shot stuff didn't touch it, I'm not sure that caustic soda will either!!

paddypaws101

I have a long snake/wire twisty thing designed to clear pipes so will give that a go too prior to trying the soda.

keirshunt

cold water, wear every kind of covering available. the first time i used caustic soda i didn't read the instructions, there is a very specific way you do it, (water on soda crystals or soda crystals on water)...can't remember which but I did it the wrong way and it splashed, everywhere. thought I was going to die, (very dramatic I am!). Anyway, be careful with it and READ THE INSTRUCTIONS...it defo tells you on them what to do. Awesome stuff by the way, clears anything, (possibly kills everything it comes into contact with too but I was desparate).

System

ALWAYS add caustic soda to the cold water -- slowly.

The reaction is exothermic so the water will heat up.

keirshunt

see....i KNEW there was a right way and a wrong way...(shame I can never remember which is which):rotfl: