What actually causes razor cuts/nicks?

[rmac]

I need someone to explain this to me in a scientific way I.e. what actually happens to a blade edge (SE/DE) to make it suddenly start digging into the skin as opposed to just floating over it?

I get to 2-4 uses of most blades (6if I’m lucky) and then they just seem to “die” i.e go from cutting perfect one day to still cutting hair, but cutting skin as well.

I had heard that the blade edge is so thin that small “chips” just break off which eventually causes some degree of uneven cut, so to speak. I know guys here have done some blade microscopy so is there any truth in this?

Also I find it strange that some edges deteriorate quickly- is this just the coating wearing off or does both the edge and coating wear off at the same rate?

Any ideas guys?


Thanks,

R

 

[Mitzie]

In general:
Weepers can be caused by the blade riding/gliding too close to skin. Something that Gillette and Wilkinson Sword/Schick have sought to address with their SkinGuard and Protector series of razors by the use of guards (wires) to prevent scaping of skin. Technique also plays a part to some extent, especially razor angle. Also the danger of the extreme edges of the blade catching the skin. And yes the sharpness of the blade also plays a part -dull blades increase the tendency to apply more pressure which potentially can cause weepers, nicks, and cuts

 

[Halfblade]

I need someone to explain this to me in a scientific way I.e. what actually happens to a blade edge (SE/DE) to make it suddenly start digging into the skin as opposed to just floating over it?

I get to 2-4 uses of most blades (6if I’m lucky) and then they just seem to “die” i.e go from cutting perfect one day to still cutting hair, but cutting skin as well.

I had heard that the blade edge is so thin that small “chips” just break off which eventually causes some degree of uneven cut, so to speak. I know guys here have done some blade microscopy so is there any truth in this?

Also I find it strange that some edges deteriorate quickly- is this just the coating wearing off or does both the edge and coating wear off at the same rate?

Any ideas guys?


Thanks,

R

I would assume that it's more due to the coating wearing off than anything else. There are people who use blades for hundreds of shaves, so it cannot be the edge or the blade wouldn't cut at all.

 

[MostaccioMan]

I cannot answer the scientific reason for the blade cutting into skin, but you need to acknowledge another factor here: the razor itself. For example, Feathers are my usual source of nicks and cuts, but when I'm careful, I can pretty much get away with it when using an R41 or 3ONE6. Stick it into a slant though, and my chance of getting a nick-free BBS is about 50%. The amount of blade flex a razor puts into the blade also accounts for its performance.

 

[BigJ]

I doubt there is a ‘scientific’ explanation; too many factors are in play IMO.

The easy answer is to blame the equipment!

(Truth be told I always blame the operator.)

 

[santamariasteve]

There are many reasons, or combinations thereof, for nicks and cuts while shaving:

Improper angle, improper pressure, dull blade, friction instead of slide, poor lather, razor too aggressive. thin skin, and more. And let's not forget operator error, or being drunk.

 

[musicman1951]

I believe weepers are virtually always a brief moment of poor technique. I often had the same problem with blades that had lost their initial sharpness. My theory is that I unconsciously added pressure to compensate for the ever dulling edge.

I found that almost all of my weepers came on the 15th pass of my usual blade, so I change blades after 12. Voila, the almost total end to weepers (although I still occasionally have senior moments).