Alum Blocks and Countertop Damage

I've used an alum block for as long as I've been shaving. I used it every day at first and now I only use it if I've had a little rougher shave to calm any irritation. I've also been using alum as a deodorant - initially a big block of potassium alum that I can no longer get on amazon and now the crystal brand "stick" crystal of potassium alum that is readily available in the drug store. I like how effective it is and how odourless it is so I get no scent clashing with whatever post shave product I might be using. Today I noticed a warning on the label saying not to place the product on marble or granite counters/surfaces. I'd never seen this before and while I'd never placed alum directly on a countertop, I'd never taken any special precautions either. I did a search and found a 5 year old post on another forum but really, not a lot of information is out there on this subject.

Does anyone have any more information on this subject or any personal experience? I think it would be a great public service if we all knew a little more about the potentially damaging effects of alum on countertops.

Thanks,

Marko

I don't have personal knowledge, though found a couple of things.

From Reddit:

"According to betelgeux, alum will eat into organic materials like that. I'd be careful. He said he had to sand and polish some scales over it."

"No doubt about it. I don't know where or when, but I already posted on a thread about how I managed to damage a marble countertop with an alum block that was only left on top of it for 5/7 minutes. It just destroyed the finish on that countertop. It takes away all the shine/finish out of marble."

I have not heard of this with alum but my everyday routine with my alum block is to take it out of its plastic case, rub it on my wet face, dry it off with a towel and stick it back in its plastic case without setting it down at all. I use alum after every shave so I have no plans to change my routine with it since it seems to be preventing my corian bathroom sink from becoming damaged. Thanks for posting.

Well, I can relate to MntnMan62's words actually, as my daily routine is kind of really similar. I take my aluminum block out of ts plastic case, rub it on my wet face, dry it off with a towel and stick it back in its plastic case without setting it down at all, and to be honest, I am not going to change my routine as well. Thankfully my Countertops are not made out of marble or granite, they is out of quartz, so I do not have any kind of issues with them. However, to be honest, I was thinking about getting a marble countertop, thankfully I did not do that .

Wow, very interesting, who would have thought you couldn't put alum on granite? as most bathroom countertops are marble or granite.Thanks for the info

I found that interesting as well. Someone above mentioned no issues with Corian. That might be because Corian is a synthetic product invented by DuPont. It’s basically fancy plastic. Expensive too. It looks like stone, or at least can but it’s much easier to work with and repair. You can use woodworking tools to cut, firm and sand/polish it.