Mitchell's Wool Fat + Styptic Pencil = WTF?!

[StueyB]

Having a lazy Saturday evening shave with MWF and a derby blade in my Gillette Slim.

Got a slick nick on my Adam's apple on the second pass, so I reached for my styptic pencil. It was quite old and the stub broke away from the little red thing and fell into the water in the sink full of warm water and promptly started dissolving.

I rinsed my face with the water in the sink and noticed that it tasked a little like sour candy or alum. However when I tried to apply the third pass of MWF lather from the bowl it literally disappeared as soon as it touched my wet face.

It was weird, the lather seemed to evaporate. Went from a lovely thick lather to nothing in less than a second.

I've used styptic pencil before between passes with other soaps and haven't seen this reaction with them. Is this just a MWF thing or was it the amount of styptic on my face?

 

[filobiblic]

Others may comment with more experience on this one, but I think it's the styptic in the water that killed your lather. A styptic is similar to alum but highly concentrated. By dissolving into the water and then rinsing your face with it, you've ended up with your face covered with it. So trying to lather over the top is a doomed affair.

If you have another styptic you could experiment with it to confirm. Wet and dab it extensively on your cheek over an area the size of 50c coin. Then try to lather over the top. You'll most likely find it won't remain on that area for very long.

Perhaps the Chemist(s) among us can tell us the chemical reaction that occurred? @alfredus ? Others?

 

[Monsta_AU]

Filo is right - Stryptic is essentially Alum (Aluminum Potassium Sulfate) plus one or more other vasoconstrictor chemicals.

Since it is a sulfate, it introduces cations that essentially kill the lather. It's also the same as having dishwashing detergent in water and washing up, then putting a bar of soap in the water. The sulfate-based detergent surfaction is disturbed by the soap anions and bang - the suds are killed off by the soap.

 

[borked]

@Monsta_AU remembered the other type, ammonium aluminium sulfate.

 

[StueyB]

Thanks for the info @Monsta_AU, @filobiblic and @borked

Tried to follow @filobiblic's suggestion of an experiment, but instead of my cheek did the back of my hand - the idea being it would be easier to photograph my hand than my cheek.

I tried my new styptic pencil (Aluminium Sulfate 98%), Alum (Shaving Alum according to the paper label stuck on it at the Indian Grocer) and Crystal Body Deodorant (Potassium Alum).

Applied the all of these in lines across the back of my hand an wrist, let them dry and applied the MWF. Similar results but not as drastic as last night. Unfortunately the photos are crap - too much yellow light.

Obviously I should wait until after the third pass before using the styptic pencil when using MWF. I'll have to try the experiment with my other soaps.