ArticlesLet’s get all domestic, and scientific.
Introduction
I have a cleaning problem area in my bathroom; the glass shower screen. No, I don’t think it is covered in mould. Instead, it appears to be covered in tiny round marks where drop have dried up and left behind grey discolouration. I suspect it is salts from the hardness in the water (Calcium? Magnesium?), but the water isn’t that hard here, so maybe I am mistaken and it is soap scum. Wait… maybe that’s the same thing? I forget my Year 10 chemistry.
Until now, I have thought that the best product for removing it has been CLR. It is also has the most obnoxious fumes, to the point of giving me coughing fits.
I was recently given a sample bottle of a cleaning product that was recommended for this problem.
Does it really work better? That sounds like a scientific hypothesis.
There is only one way to find out. Time for an experiment.
Method and Results
I sectioned off areas of the glass, wiped them down quickly with a paper towel to remove any dust, pulled out all the cleaning products from under my sink that I thought might help, and gave them each a try. I followed the directions, let them sit for a few minutes then rinsed off the glass, let it dry, and rated the results by appearance and by the amount of ardour and hardship I had to go through to achieve that result.
| Product | Active Ingredients | Applicator | Application | Ardour Endured | Result |
|---|---|---|---|---|---|
| Control 1: No action | placebo | none | no action | none | no change visible |
| Control 2: Water and scrubbing | H2O and elbow grease | scouring pad | rubbed the glass with wet scouring pad | mild physical effort | slightly cleaner than Control 1, but not much. |
| Windex Window cleaner | unspecified (believed detergent and alcohol) | spray gun + paper towel | sprayed the glass, and then immediately wiped with towel | light physical effort | there appeared to be a change to the pattern of the marks, but it wasn’t much of an overall improvement. |
| CLR (Calcium Lime Rust, Bathroom and Kitchen Cleaner Deodouriser) | Glycolic Acid (?) | spray gun | sprayed glass patchily (ran out of product), waited few minutes and rinsed off | pungent fumes took layer off my lung linings | where the foam had touched the glass, it was quite clean |
| Generic-Brand White Vinegar | Acetic acid | paper towel | wiped glass with product-soaked paper towel | light physical effort | no change from control 1 |
| Generic-Brand Mould Killer | Sodium Hypochlorite, Sodium Hydroxide and Sodium Chloride | spray bottle | sprayed glass, waited a few minutes, rinsed off | unpleasant odour | cleaner than control 1 & 2, but not clean |
| Generic-Brand bleach-based Domestic Cleanser | Sodium Hypochlorite and Sodium Hydroxide | paper towel | wiped glass with product-soaked paper towel | light physical effort, unpleasant odour | cleaner than control 1 & 2, but not clean |
| HypoKlean | unspecified (but includes some bleach) | paper towel | wiped glass with product-soaked paper towel | mild physical effort | cleaner than control 1 & 2, but not clean |
| Generic-Brand Cream Cleanser | unspecified (presumably detergent and grit) | scouring pad | rubbed the glass with product-soaked scouring pad; once rinsed, it needed another wipe down with a clean cloth to remove the filmy white residue | mild physical effort | quite clean |
Discussion
- For years I have been annoyed at anti-mould product labels that warn to only use them in a well-ventilated area. If it was well-ventilated, I wouldn’t need the product!
- CLR fumes have the power to force me to evacuate the room, gasping for fresh air. Yet its label claims that it “deodorises” and that it has a “fresh scent”. Bah!
- I am not sure about the active ingredient in CLR. It claims not to contain any ammonia, phosphate or bleach. It mentions containing Glycolic Acid in the poisons information, but I am not sure if that is a cleaning agent.
- Us scientists aren’t scared off when the instructions say not to mix the cleansers!
- White Vinegar did nothing. Take that, all those hippies who recommend vinegar to solve virtually every cleaning issue.
- Scrubbing (with water) doesn’t help much, so elbow grease alone isn’t the answer.
- CLR really does work, and without requiring physical effort.
- HypoKlean may smell better than bleach, but it doesn’t clean any better in this application; certainly not worth a special trip to buy it.
- Mould killer, while not successful, did have some effect over Control 1. Does that suggest that the stains are mould-related, despite my beliefs? Or does the active ingredients in mould killer have an effect on non-mould-related stains?
- Cream cleanser was a surprising success; I really didn’t expect it would do better than the bleaches (including the mould-killer).
Conclusions
If I want my shower glass clean, I need to either use CLR and risk emphysema, or go to the old trusty bottle of cream cleanser and start scouring.
As you may have guessed, the entire experimental area has been re-cleaned with the cream cleanser.
Anyone who wants to reproduce these results is welcome to come and clean my bathroom.
Comment by Richard Atkins on October 3, 2008
There was a fad recently for cleaners to include chemicals derived from oranges – see for example Orange Power. I notice that none of your tests includes this Important Scientific Breakthrough! For shame! How can we possibly rectify this oversight? Should us Sydneysiders inundate you with random cleaning products at the
Septembermeetup? (I mean a figurative inundation of products in their respective containers, as I don’t think spraying them on you would achieve the desired effect. Or would it?)Comment by Julie Lawrence on October 17, 2008
Ah, you see, you did the vinegar one wrong(ly?). You have to soak paper towels with vinegar, then hang them from the top of the glass so they’re touching it, and leave them overnight … THEN wipe. And I think you’re meant to heat it first too (the vinegar).
Of course, I’ve never actually tried this. My preferred method is to get in the shower, look at the filthy door, have a moment of shame guilt, then get on with my life.
Oh, and not ever invite anyone over 🙂
Comment by Julie Lawrence on October 17, 2008
SSC: am now heading to the laundry to see if i’m hiding any cream cleanser anywhere, and will then proceed to shower to test your hypothosis.
Comment by Julian on October 17, 2008
Forgive me, but I am fast becoming a vinegar-skeptic. I was recently told it could make fabrics colour-fast, but that proved to be another vinegar myth. It is the placebo of the cleaning solutions!
In any case, heating vinegar and applying the night before would fail the ardour test.
Hmmm… ardour isn’t the right word, is it? I don’t mean love and passion, I mean a measure of how arduous it is. What’s the right word?
Comment by John Y. on October 18, 2008
Well, the noun form of “arduous” is “arduousness”. Unfortunately, it doesn’t have the same brevity or ring as “ardour”, and doesn’t serve well as a column heading or the name of a test.
I’m afraid I can’t come up with a better candidate at the moment.