Chemistry advice - dissolving limescale

Yes, the advice comes from morons.

Someone has mangled the story and the echo chamber has endlessly mindlessly repeated it as so often happens.

The mix is for unblocking the drain, not dissolving limescales and works by the gas the mixture produces as the acid dissolves the bicarb.

I suspect that is so.

I descale my kettle with a commercial witches brew that is mostly pure citric acid

Glad I'm not going doolally! Now I've got to break the news to my wife that straight citric/acetic acid will work a lot better than if she adds bicarb.

Having said that, the tablets that I use for descaling by coffee machine are citric acid but they fizz as soon as they are dropped into water which suggests that there is something like bicarb in the tablet which starts to react once the acid and bicarb are in solution. Maybe they rely partly on the CO2 acting as a "drain unblocker" of the narrow tubes that run from the water reservoir, via the heater, to the cone which holds the filter paper, in addition to the acid reacting with the limescale.

Its more likely to just be something to get the citric acid tablets to dissolve.

Yeah, could be. Wikipedia doesnt have much detail that I could find on a quick look.

Yes, but the reaction of acid with the bicarb makes it fizz, which is an indicator that it is STRONG and WORKS! Also, acid descales, and bicarb cleans (as a gentle abrasive, IME) so both together will work BETTER.

ISTR James Herriot writing: he was told that after doing something necessary to a horses's hoof, to apply iodine and <something> to the hoof which would release billowing purple clouds of vapor.

The farmer would see that, say, "ah, powerful stuff!", feel he'd gotten his money's worth and pay less reluctantly, therefore the wise vet should used this.

Thomas Prufer

Yes I liked that story. He said that an alternative was something that released a bit of gas in the bottle, so the cork would make a pop when it came out, or else give it a solid sediment ("a bit of body") that had to be mixed in by shaking the bottle vigorously.

In Waitrose the sachets of descaler are about 10 times as expensive as the straight liquid 'essential' descaler.

No idea. I use neat cleaning vinegar , works well....

In 1966 my chemistry master, who used to work for a major detergent company, said that only about 5% of the product was in fact an odourless colourless detergent. The rest was colouring, scent and a thickening agent to make it look and feel 'oily', a foaming agent to make bubbles and the bulk was just water.

Marketing had determined that the average housewife liked it that way, and that she felt that two squirts into a washing up bowl was 'how much you needed', and if it didn't create a foam it 'wasn't' working' and if it didn't feel thick and soapy it was 'no good'

Give the people what they want...

How many people actually wash up with a teaspoonful of Teepol? Mind you even teepol is coloured flavoured and thickened these days

Citric acid crystals here. A 2 kg bag (£5 from Amazon) lasts me for years.

I'm sure that mixing a very small amount of bicarb in would only diminish the effectiveness a little bit, and it would give a most satisfying foam.

One might say that instead of giving them "what we know is best for them", the product has been optimised for how people actually *are*. You'll never train people that two or three drops of washing-up liquid suffices, so it's pointless trying. Thass why we buy the cheap Tesco washing-up liquid, where two squirts does the job, over Fairly Liquid, where two or three drops would do it. Cos I know what SWMBO does at the sink :-)

There's a lesson for government there.

You can get 250g for £6 from Amazon. Beats the £10/teaspoon* for the official descaler for the coffee machine.

Also useful for making invert syrup, which is pretty DIY :)

Have you ever compared the effectiveness of citric acid against white vinegar? Both are darn sight cheaper than Oust de-scaler.

In my long life I've used just about everything to remove limescale. The big problem is that some attack chrome.

Below that any acid will do. Citrus fruits, brown sauce, vinegar, hydrochloric acid, sulphuric acid, coca cola, formic acid, phosphoric acid. All works. The issue is side effects.

Citric is *much* better, especially if you make a warm saturated solution. It works more quickly, which is important if the thing you're cleaning is awkwardly shaped so you can't steep it in the fluid for a long time - for example citric solution spray works on shower screens in the time it takes to run off, whereas vinegar doesn't do much.

(I once tried to thicken vinegar with flour to make it stick better. It did not go well - I made sourdough)

Theo

I have been known to water down liquid soaps/detergents, to avoid overuse...

Water it down, and then add salt. This (in most detergent formulations) thickens the solution, so it doesn't "look weak".

Thomas Prufer

I vaguely remember some vintage tv adverts for Fairy Liquid in which they claim a thimbleful would do all the washing up.