Instant edge degradation

So the other day I was in a pinch and all that was available to shave was some antibacterial handsoap. I started with a razor I honed only about a month ago and passed the HHT fine after stropping, but about 30 seconds in I noticed a lot of tugging and general discomfort. The blade had also started to patina (like you get blueing on a carbon kitchen knife). Afterwards even with stropping the blade is definitely dulled, I'm assuming due to corrosion. Has anyone experienced anything like this before?

I don't think triclosan could have anything to do with it, and the only thing acidic was phosphoric acid at the end of the ingredients list. I'm wondering if that might have been enough...

Weird. Wouldn't expect that. I always thought that soap is basic

Also why on earth would you be out of soap/cream!? Any self respecting wet shaver should have at least a years supply if not more. Seriously.

Michael

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Originally Posted by mjsorkin

Also why on earth would you be out of soap/cream!? Any self respecting wet shaver should have at least a years supply if not more. Seriously.

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Haha I have about 2 years' worth, I was just at a friend's who turned out not to have anything.

Phosphoric will eat steel bigtime,if you look at a razors edge on a microscopic level,who knows.

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Originally Posted by mjsorkin

Weird. Wouldn't expect that. I always thought that soap is basic

Also why on earth would you be out of soap/cream!? Any self respecting wet shaver should have at least a years supply if not more. Seriously.

Michael

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Priceless !
On the day of my wedding in the hotel, I shower, fill scuttle, dunk brush, strop razor, go to lather and no soap!!! I mixed a little hotel shampoo and conditioner and it worked perfect.
I have at least 2 years supply here at home ;)

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Originally Posted by mjsorkin

Weird. Wouldn't expect that. I always thought that soap is basic

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If it's got phosphoric acid in it it isn't a base nor a soap. :)

Soap should be alkaline - it's possible that if it's too alkaline they add acid to bring the pH down a little bit.

Was the patina forming after the hand soap was used or prior to that ? Hard to explain a sudden degradation.

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Originally Posted by ScienceGuy

So the other day I was in a pinch and all that was available to shave was some antibacterial handsoap. I started with a razor I honed only about a month ago and passed the HHT fine after stropping, but about 30 seconds in I noticed a lot of tugging and general discomfort. The blade had also started to patina (like you get blueing on a carbon kitchen knife). Afterwards even with stropping the blade is definitely dulled, I'm assuming due to corrosion. Has anyone experienced anything like this before?

I don't think triclosan could have anything to do with it, and the only thing acidic was phosphoric acid at the end of the ingredients list. I'm wondering if that might have been enough...

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Phosphoric acid for sure also explains the instant patina see "pickling" below.

The good news is that no long term harm would have been done. Rinse
well wipe clean with paper and hone it back into shape.

From Wikipedia:
"Phosphoric acid may be used as a "rust converter", by direct application to rusted iron, steel tools, or surfaces.
The phosphoric acid converts reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate, FePO4.
""Rust converter" is sometimes a greenish liquid suitable for dipping (in the same sort of acid bath as is used for
pickling metal), but it is more often formulated as a gel, commonly called naval jelly. It is sometimes sold under
other names, such as "rust remover" or "rust killer". As a thick gel, it may be applied to sloping, vertical, or even
overhead surfaces.
"After treatment, the black ferric-phosphate coating can be scrubbed off, leaving a fresh metal surface. Multiple
applications of phosphoric acid may be required to remove all rust. The black phosphate coating can also be left
in place, where it will provide moderate further corrosion resistance (such protection is also provided by the superficially
similar Parkerizing and blued electrochemical conversion coating processes)."

I am however astounded that it was so quick.
Interesting.

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Originally Posted by HNSB

Soap should be alkaline - it's possible that if it's too alkaline they add acid to bring the pH down a little bit.

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Well not very alkaline if all the lye reacted with the fatty acids correctly. It should
be near neutral (7).

Harsh hand and laundry soap was purpose made to be under-reacted
so the remaining lye could saponify the oils and such we all shed. This saponification was
why TSP was such a good cleaner but the abundant phosphorous proved problematic
in streams and lakes. TSP is Trisodium Phosphate.
Trisodium phosphate - Wikipedia, the free encyclopedia.
The pH of a 1% solution is 12 (very alkali) , and the
solution is sufficiently alkaline to saponify grease and oils.

Compare and contrast phosphoric acid with this alkali.

The reactions that happened on your blade happened along the surface, and along that edge there's more surface area relative to the volume of steel. For that reason it doesn't surprise me that you noticed a degradation as the phosphoric acid deposited out along the blade.