Best product for this job: 6-PACK High Precision Polishing Sanding Wet/Dry Abrasive Sandpaper Sheets -Grit 3000 5000 7000 Germany
For those who don’t want to read the whole post: Purchase high-quality fine-grit sandpaper like as linked above. Choose the highest grade, wet it with water and gently rub deposits. Bam! You’re done. For more sever stains, drop to the 5k or 3k grit for faster results and work your way back up to smooth the glass and make it more resistant to staining.
I remember as a kid entering my first year of college and living on my own for the very first time, I knew nothing of the art of cleaning. I knew how to make my room (usually after several threats from Mom), but deep, detailed cleaning completely eluded me, like it did most of the guys that I was roommates with. Not one of the four of us was a clean freak, unfortunately. We were all terrible slobs.
And I was their King.
But as every young Slob King learns very quickly; that lifestyle doesn’t fly very long. Half way through the first semester, I was brushing my teeth in the bathroom and I was staring at the glass shower door. It wasn’t a very pretty bathroom to begin with. There were weird burgers and chickens printed on the wallpaper, but that glass shower door seemed off. It was a gray white fog color, kind of like etched glass.
“Wait, wasn’t that shower door glass clear when we moved in??”
Turns out, yes it was.
It was covered in layers and layers of hard water deposits.
So I gathered the dudes for an emergency bathroom meeting. There we were, standing in front of the glass, hands on struggling freshman goatees, contemplating how on Earth we’re going to clean it.
“Guys, we can’t keep living like this” I said as their King. General sounds of agreement were grunted and then two weeks went by and nothing was done.
Then we revisited the issue and we hit it with all we got. Windex, Bar Keeper’s Friend, steel wool, muscle, lemon and vinegar, WD-40. It was getting nowhere.
I wish I knew back then what I know now.
Flash forward to today, and the King of Slob has conquered new land and is now known as the King of Clean (at least to my staff). In life’s mysterious ways, I now own a top-performing cleaning company with killer techniques and even better staff.
In the early days of this house cleaning business, I found out fairly quickly what works and what doesn’t on hard water deposits. I had to figure out an extremely quick, safe, and green approach to tackle even the worst cases of hard water stains.
Before we get into that, let’s talk about the nitty gritty of what makes hard water stains in the first place and why cleaning them can be a nightmare.
Hard water deposits are usually made up of calcium carbonate and magnesium deposits found in hard water. The more of this stuff that is found in your water, the harder it will be. It basically creates lime scale on any surface it is allowed to dry and evaporate off of. The best method to prevent this build up is to keep the shower door open and the bathroom fan on.
In cases where there is only a light layer of deposits, you can use a simple mix of dish soap and vinegar or a lemon and the acid will break down the deposits quite easily. The reason this method stops working when there are many layers of deposits is because there is no way to keep the liquid solutions (even stronger, more dangerous acids) on the glass without it dripping off before it has had a chance to work through all the layers. Even the foaming products eventually run off, and there is nothing worse in the world than the fumes they make.
What this means is you’ll have to reapply the solution over and over with vigorous scrubbing to completely clean the glass and this can take many hours in some cases. So unless you have horizontal shower doors, cleaning solutions just aren’t worth it.
So what’s the solution? Sand paper.
I thought it was crazy at first, but being an automotive DIY enthusiast, I know there are extremely fine grades of sandpaper meant to give a mirror polish more than abrade. So, to find what grit it is safe to start experimenting with, I looked at the grit equivalent of some common household cleaning supplies:
4/0 steel wool = 400 grit sandpaper
3/0 steel wool = 280 grit
2/0 steel wool = 180 grit
2/0 steel wool = 120 grit
White Scotchbrite = 1200 grit (it has no abrasive)
Gray Scotchbrite = about 400 – 600
Maroon Scotchbrite = about 220-280
Green Scotchbrite = about 150 – 180
Now this was interesting to me since the finest grade steel wool was an extremely aggressive 400 grit, and I discovered it can easily scratch glass and STILL not clean off the hard water deposits. The typical green and yellow scrub pads were even worse!
I knew that sandpaper can be purchased at up to 7000-10000 grit, but I started experimenting with 5000 grit first. That is multitudes finer than any of the supplies mentioned above and resembles a piece of blue paper. I took it to a shower glass door that had some moderately heavy deposits on it, and it blew me away. It literally cut through the deposits like butter and the entire shower door took me less than a minute to clean.
But the grit was so fine that it not only cleaned the door, it also polished out tiny scratches that were left behind by more aggressive products and acid etching.
I realized that for extremely heavy hard water stains, I can drop to a 4000 grit paper and get the job done much more quickly, or even 3000 and work my way back up to 5000 to take out any micro scratches.
I suggest you wet the sandpaper with water to provide a lubricant effect and make it easier to pass over the deposits and glass.
Till next time,
Alex – Heromaid Owner