Shower Screen Cleaning - Why the stains don't come off

April 21, 2017

Shower Screen Cleaning – Why don’t the stains come off? A brief (maybe too long for some) introduction into the chemistry of glass corrosion

Lime Scale, Hard water stains, calcium deposits, soap scum, it has been called many different things, the questions is: How can I get it off?

By the time you read this you have probably searched hi and lo on the internet for a solution to your shower screen problem. Every self-respecting tips and tricks blog on stain removal has tons of well-meaning advice from people swearing it does wonders for them.

So why on earth does it work for them and not for me?

If you just want a quick answer rather than the full story, here it is:  The “stains” don’t come off because they are not really stains, they are in actual fact what experts called “glass corrosion”. And the same as with metal corrosion it can’t be cleaned off. It has to be removed mechanically.

Still interested? Then read on... “How come glass corrodes? I have never heard that before”.  Well, it’s true that under average conditions glass corrosion is very slow, even unnoticeable. But as soon as there is a constant exposure to water and if this water is slightly alkaline, that changes rapidly. Now some of the components of the glass mix (What’s glass made of- insert Glass Facts) are leached out of the crystal structure and leave gaps in the surface.

From here on more complicated chemical reactions take place. If you don’t mind a bit of chemistry, you can read more about here (inser International Glass Review)

So much for the reason, why some glass get’s “stained” and other glass does not. For the most part it has to do with alkalinity (pH of 8 or above) in the water. Water running off concrete or in baths and showers is in that category – remember that soap is alkaline (rings a bell?). Water splashing from swimming pools or in marine environments , i.e. where water stays on the glass for a long time, has a similar effect

Ok then, but how do you get the corroded layer off? Well, you can try mild acids as most of the household cleaning forums suggest: Lemon juice, vinegar, acidic bathroom cleaners, etc  - you get the picture. That may help for a while, but in some cases it might make it worse in the long run (read here why – check the paragraph on culinary acids!).

If you have tried all that and it did nothing for you, i.e. if the corrosion has progressed a fair bit, the only solution left is mechanical removal. How mechanical? Mechanical enough to require a drill or a polisher, because it is basically a cut and polish process. “Cut”, as in with an abrasive and “polish” with something called cerium oxide.

Just in case you have not totally lost interest by now and if you really need to get that shower looking sparkling again, here are a couple of suggestions: Type “Glass Polishing ”into search engine and look for a service provider that can polish it for you or look for a DIY kit that you can use for the same purpose. Of course, you could also look on our web shop for a suitable DIY kit. And then there is the question: How do I stop it from happening again? But that is another story