DIY Potassium Alum block

[sg.]

The picture below shows how I made two blocks of Potassium Alum suitable for use after-shave as an astringent and antiseptic. The starting point was McCormick Potassium Alum powder.

The two pieces will last me a very long time, but if I had to do it again, I would try the following simpler method: Heat 100 ml of water to under 90C; add one packet (53 grams) of McCormick Alum and stir vigorously; pour solution into small paper cup (e.g., paper espresso cup; pour boilng water into this cup and empty it prior to pouring the solution) though a coffee filter; a solid mass will start forming at the bottom in an hour -- wait for a day and take out the solid mass and dry it with paper towel.​

 

[Atlantic59]

Interesting Chemistry experiment!

My favorite is currently an alum stick in a carrying case, like this. Only costs a few dollars.

 

[global_dev]

pour solution into small paper cup though a coffee filter;

so the filter gets tossed after the solution is poured through, right?

 

[CCR]

I'am going to give this a try this weekend

 

[FarmerTan]

Ingenious @sg. !

 

[sg.]

so the filter gets tossed after the solution is poured through, right?

Yes. The filter is there just so that no tiny particles end up in the solution.

 

[ERS4]

Being able to see the process and experience of the hands-on experiment-expanded my horizons.

Potassium Alum block is very cheap in the area where I live. The neighboring herbal shop can buy more than 100 grams for only one dollar, and just grind surface well be good.

 

[sg.]

Potassium Alum block is very cheap in the area where I live.

Which location is that? And what is the colloquial name?

In Northern California, one can buy relatively cheap alum from East Indian stores -- but it turns out they are ammonium alum, not potassium alum. The packaging just says "alum" -- I had to do some tests to determine what exactly they were. (Figuring out if your Alum is indeed Potassium Alum - https://www.badgerandblade.com/forum/threads/figuring-out-if-your-alum-is-indeed-potassium-alum.594988/)

 

[MntnMan62]

Neat idea. But it seems like an awful lot of work to go through when a block of Osma alum costs about $8 and lasts anywhere from 1 year with shaving 6 to 7 days a week to 3 years shaving 2 to 3 days a week.

 

[sg.]

it seems like an awful lot of work to go through when a block of Osma alum costs about $8

Unless one is impatient and cannot wait for delivery. To elaborate on my context: A few years ago, I first heard of alum's use in shaving, but the only definite statement I came across was DrMatt357's "alum is kryptonite for shaving". Recently, I noticed that @Slash McCoy used (omega-brand?) alum in his blind-folded shave video, and came across GeoFatBoy's video on after-shave tasks; and these two videos made me impatient to try alum.

But having tried it, I might not use it much. Reason is that it is very hard to get rid of K-alum from finger tips and lips (from when I tasted a solution and perhaps also from use of alum after shave)! It seems to attach to the skin in some strange, permanent way -- with the only way of getting rid of it being to grow new skin. It might also be being absorbed -- and who knows what it is doing inside! I will try again after a month or so to make sure the bad effect is not from the prior use of ammonium alum rather than from the K-alum.

 

[MntnMan62]

Unless one is impatient and cannot wait for delivery. To elaborate on my context: A few years ago, I first heard of alum's use in shaving, but the only definite statement I came across was DrMatt357's "alum is kryptonite for shaving". Recently, I noticed that @Slash McCoy used (omega-brand?) alum in his blind-folded shave video, and came across GeoFatBoy's video on after-shave tasks; and these two videos made me impatient to try alum.

But having tried it, I might not use it much. Reason is that it is very hard to get rid of K-alum from finger tips and lips (from when I tasted a solution and perhaps also from use of alum after shave)! It seems to attach to the skin in some strange, permanent way -- with the only way of getting rid of it being to grow new skin. It might also be being absorbed -- and who knows what it is doing inside! I will try again after a month or so to make sure the bad effect is not from the prior use of ammonium alum rather than from the K-alum.

I'm certainly no scientist or expert on alum. I've read that potassium alum molecules are too large to be aborbed by the skin. However, I've also read that you don't want to leave potassium alum on your face for much longer than a few minutes before rinsing it off with water. That said, I use it immediately after my final pass/touchup as I find it soothes any irritation and stops any weepers I may have created. I also find it to tighten and "tone" my skin and it seems to continue to tone for a bit after I've rinsed it off with cold water. I'll apply it to my entire face and then clean up my gear before rinsing it off with cold water. I then apply witch hazel with a cotton ball and leave the witch hazel on my face to dry. I finish off with an aftershave or balm (in the winter). I have never been bothered by any taste from it since I don't use it on my lips. And I find that the toning effects tend to disappear fairly quickly. I most definitely do not notice any permanence to the use of potassium alum, either on my face or my fingers. But that's just me.

 

[sg.]

I don't use it on my lips

Me neither. I got a taste of alum during my tests (forgot to mention the taste test in my post on testing for potassium alum); also, the taste seeped in accidentally when the alum moved across the two tips/ends of my lips.

 

[MntnMan62]

Me neither. I got a taste of alum during my tests (forgot to mention the taste test in my post on testing for potassium alum); also, the taste seeped in accidentally when the alum moved across the two tips/ends of my lips.

Ok. So then why would you use taste as a factor as to whether you use alum or not? Did I understand your statement correctly? "I might not use it much. Reason is that it is very hard to get rid of K-alum from finger tips and lips..."

 

[sg.]

Did I understand your statement correctly?

To elaborate on my reasoning: The fact that it has been difficult to get rid of alum residue acquired during prior use/experiments (wherever on the body such residue might have been) and the fact that the contact during prior use/experiments was not prolonged leads me to conclude that it would be equally hard to get rid of alum residue from "normal" use -- even if such normal use involves washing off the alum within 30 to 60 seconds of applying.

 

[Clay S]

I don't taste alum on my fingertips after using an Alum block, and I haven't washed my hands. I did handle a damp cloth though.

 

[ERS4]

Which location is that? And what is the colloquial name?

In Northern California, one can buy relatively cheap alum from East Indian stores -- but it turns out they are ammonium alum, not potassium alum. The packaging just says "alum" -- I had to do some tests to determine what exactly they were. (Figuring out if your Alum is indeed Potassium Alum - https://www.badgerandblade.com/forum/threads/figuring-out-if-your-alum-is-indeed-potassium-alum.594988/)

I live in Taiwan, a small Asian island country.(Between China and Japan)
The alum block sold in "Chinese Medicine Store" is designated for medicinal use and must be recognized and managed by government, so it must be potassium alum.
Although wet shaving is not very popular here, this is good news for us.

 

[sg.]

I'am going to give this a try this weekend

Did you get a chance to try making a block? Any pictures to share?

 

[CCR]

Did you get a chance to try making a block? Any pictures to share?

Nah sorry i didn't, had the grandkids all weekend but i will try to do it this week. Sounds like a fun experiment to do