#1
I've read on previous posts that some razor blades exhibit greater sharpness and a better shave after the first shave. Can someone scientifically explain how that is even possible?

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#2
(03-17-2024, 08:46 PM)Zantetsuken Wrote: I've read on previous posts that some razor blades exhibit greater sharpness and a better shave after the first shave. Can someone scientifically explain how that is even possible?

In the case of blades presenting a higher degree of sharpness after the first shave, I believe a common explanation is the reduction/wear of coating material that occurs in the first shave or two. A number of razor blade analysis and studies often make note of this phenomenon. Of course this only applies to blades that have some form of coating to begin with, which many seem to have.

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#3

Mike Distress
New Jersey
(03-17-2024, 09:23 PM)rocket Wrote:
(03-17-2024, 08:46 PM)Zantetsuken Wrote: I've read on previous posts that some razor blades exhibit greater sharpness and a better shave after the first shave. Can someone scientifically explain how that is even possible?

In the case of blades presenting a higher degree of sharpness after the first shave, I believe a common explanation is the reduction/wear of coating material that occurs in the first shave or two. A number of razor blade analysis and studies often make note of this phenomenon. Of course this only applies to blades that have some form of coating to begin with, which many seem to have.

That has been what I have read or heard. Coated blades can become sharper once the coating is worn off. RayClem is more of an expert and has a full thread on blade comparisons for those interested.

https://damnfineshave.com/thread-rayclem...valuations

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integritas pietas fortitudinem
#4
I'm not sure they get sharper.  Instead, I think they get smoother.  I always wipe a new blade with an alcohol wipe before using, and that seems to give me better consistency.  I've read that wiping the blade removes the coating.  If that's true, doesn't a first use remove the coating too?  I just know it works for me and the alcohol wipe adds a measure of sterility to a new blade.

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#5

Member
Chicago Suburbs
Blades tend to fall into one of three categories.

1. Some blades are sharpest on their initial shave and then start to deteriorate as you use them. The Feather Hi Stainless blade is one such blade. It is super sharp out of the wrapper, but because the Japanese steel is so hard and the edge is sharpened to such a thin apex, the edge is fragile and begins to deteriorate as soon as it contacts your beard. For those with fine beards, this deterioration might take place over many shaves. For my tough, coarse beard, it happens quickly. While the 1st shave with a Feather blade is wonderful, the second one is not quite as good. If I try to make it through a 3rd shave, I find that the blade has become harsh on my sensitive skin due to tiny chips (microchips) in the edge. My experience with Feather blades is not unique. Others have reported a similar experience.

2. There are some blades that are fairly consistent (+/- 10%) from shave to shave until they are no longer sharp enough. Some prime examples of this type of blade are: Gillette Nacet Stainless, Personna Platinum, Derby Premium, Gillette branded Wilkinson Sword, 7 O'Clock SharpEdge (yellow), Astra Super Platinum, Treet Platinum, and Voskhod,

3, The third category consists of all other blades. This is the largest category overall. These are the blades that become sharper with use. Some blades are produced with a very thick coating. This coating acts as a sheath around the edge, but this sheath is only a few molecules thick, but it is still sufficient to round the apex of the blade slightly. This makes it less sharp. Polymer coatings (PTFE) are relatively soft and are easily removed. That is why some blades come with a warning "Do not wipe blade". Other blades have a metallic coating sputtered onto the edge in molecular thickness. These metals include: platinum, chromium, tungsten, titanium, iridium and ceramic. These materials are much harder than polymer and help extend blade life. Most metallic coated blades also have a top coat of polymer. As you shave with these blades, the coating will wear away due to contact with your beard and skin. As this occurs, the apex of the blade becomes less rounded as you approach the bare steel. This allows the edge of the blade to become sharper. The best examples of these blades are: 7 O'Clock Super Platinum (black), Wilkinson Sword Classic (Germany), Gillette PermaSharp Super, BIC Chrome Platinum, Personna Comfort Coated (lab blue). These blades ibecome 20-30% sharper over the 1st shave. If you are not expecting this change, you might get significant irritation or even draw blood on the ATG pass. Many other blades become 10-20% sharper during the 1st shave.

In my DE blade evaluation series, I have found a number of blades that started out mid-sharp (significant blade resistance) during the WTG pass, but by the time I reached the ATG and clean-up passes, they had become sharp enough for me to achieve a near-BBS shave, something that I cannot do with most mid-sharp blades.
#6
(This post was last modified: 03-25-2024, 03:01 AM by Zantetsuken. Edited 1 time in total.)
This has been my experience with the feathers as well. Based on your spreadsheet I will give the Bics a try. I basically only grow hair on my chin and upper lip and I don’t imagine my hair is coarser than average, they will probably last me a long time.


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