I got to thinking about this at work this week. If a man were to urinate on the same spot in the same urinal at least once every work day, how long would it take to create noticeable wear in that spot? I would imagine it would depend on both the acidity and volume of the urine, as well as the quality of the urinal itself.
You have entirely too much time (and maybe more) on your hands at work.
Maybe he works as a materials engineer in a urinal factory.
It’s a legitimate, interesting question - why dump on the OP in the first post?
To the OP: Are you assuming flushing or not? Because I think that would make a big difference in how the urine affects the porcelain, how long it stays on.
Also, urine isn’t acidic very much, but contains ammonium, though usually that’s extracted by letting it rot.
For that matter, what is the hypothetical peer eating? Diet affects the products in urine.
[nitpick]Vitreous china, not porcelain.[/nitpick]
Two different sources say the average service life of workplace restroom fixtures is 20 years; presumably that includes more than one person using the urinal. My WAG is that the metal fittings will corrode long before the china shows wear. This will require maintenance, which includes cleaning, and you’ll have to start the test over again.
An interesting question. I’m guessing, though, that you’re talking almost geological time scales. Consider that a porcelain sink has to endure much greater volumes of water (unless you’re a racehorse) and generally those do not show much erosion. At least, my 40 year old fixtures (yeah, I have to remodel) don’t show anything more interesting than some mineral staining.
Even the flush of the water through the urinal is much greater than any volume of urine. And the glaze on the porcelain is designed to be non-reactive. So for one person? I’m guessing hundreds of years. (I’m assuming we’re talking wear visible to the naked eye and not microscopes and micrometers. Because this is not the science grant I’m applying for.)
In the old building where I worked Armored, there was a generally disused restroom upstairs from the back garage. In it were old urinals from when the building was built in the early 1900’s. They didn’t show any wear from liquid flow, although the floor level base of them did show wear from foot traffic.
He said “dump on,” heh heh…
Yeah, I wouldn’t have thought there would be any measurable erosion. The glaze on porcelain is essentially glass, which is pretty hard and chemically inert. Urine is pretty close to neutral pH, and the volume of flow is hardly that great. Unless you have kidney stones, which might conceivably chip the glaze