Cleaning a glass shower screen

[Sam Plusnet]

Our 'Shower over the bath' has a curved glass screen. It's around 10 years old. Over the years it has developed what _looks_ exactly like a water scale coating - except:

a) We have very soft water, and

b) All the obvious treatments for water scale have failed to make even the slightest improvement. Yes I could always find a stronger acid concentration, but even white vinegar should have done some good.

I have even tried to (gently) use Cerium Oxide Powder to polish it, and that didn't do any good.

Any suggestions?

I have wondered if there is something in the rolling process, used to produce a shatter-proof curved screen, which would leave a faint texture in the surface?

[The Natural Philosopher]

Have you tried 'daily shower cleaner' I use this from waitrose and its not just a mild acid. Its a witches brew of surfactants solvents and lord knows what else, And it works. I get faint deposits from my softened water. It removes them

[Max Demian]

I use Mr Muscle Shower Shine: you spray it on the wet surface after showering and just leave it. It reduces the build up of lime scale; I don't know whether it will help in your case.

[The Natural Philosopher]

It is three times the price of Waitrose essential shower shine

[Theo]

I've not heard of this happening, but if your water comes from sandstone a tiny fraction of it dissolves into the water, like it does with limestone. In limestone's case the dissolved salt is very happy to precipitate out at higher temperatures as calcium carbonate, and in sandstone's case if you evaporate the water it would form silica (SiO2).

Silica is much less soluble in water than calcium carbonate so the amount in water is relatively low, but maybe if you evaporate enough water over a long time it will build up?

Unfortunately glass is also made of silica, so there could be a strong bond with the deposited layer. Maybe there's something about your screen which encourages the bond?

This is all hypothetical - I don't know if this is a real problem in a bathroom scenario but it happens geologically (where the temperatures and pressures are much higher).

Can you make any progress mechanically, eg scraping? Maybe it isn't as bonded as it seems.

Unfortunately the best acid to dissolve silica is hydrofluoric, which has certain issues.

Theo

[Sam Plusnet]

Hydrofluoric has _lots_ of issues - it will issue forth, if you keep it in the wrong container.

[Sam Plusnet]

We have tried several branded cleaners, but none have had any effect.

[Another John]

Have you tried "The magic Sponge"? I was told about this only a few weeks ago (the chap had found it had a magical effect on his dirty coffee mug). I bought some -- they seeem to be ore available in the cheap shops like B&M, Poundstretcher etc.

"Try on a small area at first", as they say. Also: Read Me:

Y'never know!

John

[Sam Plusnet]

No I haven't - but you have reminded me that I have one or two of those lying around somewhere. Worth a shot (if I can remember where...)

[Clive Arthur]

This is probably Calcium Sulfate. There is nothing much you can do chemically, but you should be able to scrape it off with some hard plastic (plectrum?) and elbow grease.

[Jeff Layman]

Somewhat counter-intuitively, it appears that the solubility of calcium sulphate is higher at lower temperatures than hotter ones. So if it is calcium sulphate, the OP should try water from the fridge rather than hot water.

[SteveW]

Have you tried normal washing up liquid and a brush? I've found that pretty effective (soft water area).

[The Natural Philosopher]

if it is an insoluble inorganic compound that doesn't respond to chemical attack, then whatever those kits are that are used to polish plastic headlights back to health might work. I.e. "It will just buff out" :-)

In domestic terms a pumice loaded cleaner like cillit pong or whatever its called, Or metal polish. Or T-cut.

i.e anything with a micro abrasive

[Clive Arthur]

Another thing - when you've managed to remove it, to drastically reduce its recurrence use a soft silicone rubber (not window cleaner's black rubber - too harsh) squeegee on the glass after every shower. At a guess, I reckon there's maybe 100 times less water on squeegeed glass than glass with water drops on.

We had this after we'd fitted a water softener in a hard water area. My guess is that prior to this, the small amount of Calcium Sulfate was mixed in with the large amount of Calcium Carbonate and was removed with the normal acid descalers. With no Calcium Carbonate left due to the softener, the Sulfate had free rein. Or something.

[Sam Plusnet]

Worth a try - if only on a sample area. Like when cleaning windows, you can only really see the 'dirt' when you are on the other side of the glass.

I always use an (absorbent) sponge to dry the glass. The curve of the glass makes it very difficult to use anything like a squeegee.

[wasbit]

Wow! Waitrose Daily Shower Cleaner is £4 (larger refill £7). Didn't see any Mr Muscle Shower Shine but if it's around £12 then they know how to charge for the convenience.