Bruce Napier wrote: > Apologies to Pete S on canals-list for this one: > > We had a debate across both these lists awhile back about descaling > toilets, with the conclusion that strong organic acids such as citric > were the answer. > > Since then, LeeSan have produced a descaling fluid which is basically > strong phosphoric acid, and I've been trying it for the last six > months. > > I have to say that it does the job, both for toilets and other places > where mineral deposits are unwelcome, such as kettles. > > You are recommended to use it at 10 - 20% dilution, but I've just > used some neat on some stubborn scale on the base of my stainless > steel kettle, and it was remarkably fast (as in, slosh 20 ml or so > around gently and watch the scale dissolve.) > > It claims to be biodegradable, which I guess it is, eventually; just > remember that your skin is certainly biodegradable under assault from > strong acid and wear rubber gloves and eye protection whilst handling > it (said it for you, Ron!)
It's strong, but not that strong (it doesn't dehydrate like some acids) (eye protection *always* advisable, however!). Having said that if it works so well (I've not tried it yet), pour a can of coca-cola in the kettle and boil it. Coke is high in phosphoric acid. Ron Jones Process Safety & Development Specialist Don't repeat history, unreported chemical lab/plant near misses at http://www.crhf.org.uk Only two things are certain: The universe and human stupidity; and I'm not certain about the universe. ~ Albert Einstein
