"doozer" wrote in message
...

AIUI Viakal is a mix of Maleic and Sulphamic acids, hydrochloric is
common in brick cleaner.


Could well be. I've got some downstairs but it felt like such a long way
to walk just to check I thought I would try relying on the brain. Either
way, Viakal will still be much better at removing limescale.

Any strong acid will remove limescale (such as old battery acid - but you
are on your own if you try that as you will need to dilute it a bit )).
Weak acids will work they will just take a really long time.

Battery acid is sulphuric acid? When it reacts with the calcium scale, it
will produce calcium sulphate, which is insoluble. So I don't recommend it.

Buy a lemon and rub it over the surface.The juice contains citric acid. Or
buy citric acid crystals from the chemist and make up a dilute solution
inwater.

Keith G. Powell