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Extending blade life

The title of this thread may well have been the exact search string I put into Google the day I learned about DE shaving. I wanted to extend the life of my cartridges and ended up ditching them altogether.
 
The ultimate tensile strength of Copper is 210-220 MPa. The ultimate tensile strength of human hair is 380 MPa. Beard hair is tougher than Copper at the same thickness. There is no doubt that DE blade edges degrade from use. Teflon, Platinum and even Titanium DE blade edges degrade with use.

It's common practice to rub straight razors with oil. This keeps the air and water away from the metal preventing corrosion. Maybe they stored blades in Oil?

(Edit: Some people strop their blades to extend the life. I've heard hand stropping, leather stropping, jeans stropping and corking but results always vary)

I am not sure I understand. Tensile strength has to do with breaking points. Don't we want hardness numbers.
 

musicman1951

three-tu-tu, three-tu-tu
One of my hobbies is cabinetmaking. When cutting dovetails I frequently resharpen the tips of the chisels. I'm not saying your beard offers as much resistance as a walnut board, but I don't understand how anyone could think the working edge does not dull with use.
 
I understand your logic.

But...I don't get the reference to copper. Aren't our blades made of steel?
You have to remember that when you are talking about the blade, you really mean the blade edge which can be measured in microns. This vastly reduces the material's ability to withstand damage. The Copper is a metaphorical aid to help visualise the surprising strength hair has. Some people like blades after the smooth coating has come off which is ironic or steelronic? :lol:
 
Here is a 1970 article from Popular Science that explains how chromium hardness coatings were expected to improve blade life. Corrosion is a large part of the story: but this innovation came from Schick. Naturally Gillette followed.

https://books.google.com/books?id=V...AWHnqmYDA&ved=0CCYQ6AEwAA#v=onepage&q&f=false

Also a 1931 Popular Science article airs the "corrosion wears more than shaving" theory, long before modern stainless blades.

https://books.google.com/books?id=C...ASe9baoDA&ved=0CDMQ6AEwAg#v=onepage&q&f=false

It has long been known that corrosion... does more damage to a razor blade than does shaving...
 
This is a worthwhile discussion, but it's not entirely meaningful unless we have a way to measure the variables.

Ideally, we'd have to make microscopic pics, and compare four blades: (1) used blades that are dried immediately after shaving, (2) used blades that are left in the razor, undried, (3) used blades that are left in a preservative solution (like mineral oil), and (4) a control blade. We could compare the pics daily to document the corrosion (or lack thereof). Keep the experiment going for at least a week.

I think the experiment could be interesting. Anybody here have a scanning electronic microscope?
 
Anybody here have a scanning electronic microscope?

No need for an SEM. Folks in the SR forum use regular hobby microscopes and USB microscopes to check their edges. That should be good enough, unless we are only talking about a couple atoms of difference.
 
Well, everyone covered everything about older days meant different metal, coatings, etc.

So instead, I'll reminisce about my father telling me about the time a friend of a friend once told him that he was able to get 5,000 per gallon with his car. Not knowing what was going on, he called the dealership, which told him to come in right away. He saw them take something out from the engine and now his car was now getting normal mileage per gallon... something about a conspiracy with the government to keep gas prices high at 50 cents per gallons or something.

I'd hear that story at least once a year.... good times.
 
I remember hearing about the research, but I have no concrete evidence of it.

No SEM and no scientific measurements. But I did experiment a few years ago.

I got a small bowl and used a single serve yogurt cup as an insert. Took a bit of trying to find a pair that fit together well. But I managed.

My theory was that by slicing a few small slits in the yogurt cup any water on the blade would drain away to the bottom of the mineral oil filled bowl.

Occasional dumping of the contents to add fresh oil was about every 10-12 weeks.

My final conclusion after about 10 months of pretty faithful use was that it might have made a difference, but it really wasn't worth the effort.

I cannot say for sure that any "extra shaves" I got wasn't because I was paying closer attention to my shaving. After all, I just took an Astra SP to 18 shaves just leaving it hanging in my shower stall after every shower. No special efforts other than paying attention to technique and prep.

So, does it extend the life? - Probably a little. Certainly in the days of carbon steel it would have been astonishing.

Is it worth it? - Not to me. But YMMV.

It isn't hard or expensive to try. Just eat a few plastic cups of yogurt and fruit to get a couple of bowls that fit together well. Slice a few slits in the inside chamber. And pour in some baby oil.

MB
 
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... a friend of a friend once told him that he was able to get 5,000 per gallon with his car. Not knowing what was going on, he called the dealership, which told him to come in right away. He saw them take something out from the engine and now his car was now getting normal mileage per gallon....

Gotta love the stories about that secret carburetor the oil companies squashed as well. Make the car get 3000% of the available chemical energy out of every gallon of gas. The drawings probably got burned up in a fire.
 
Gotta love the stories about that secret carburetor the oil companies squashed as well. Make the car get 3000% of the available chemical energy out of every gallon of gas. The drawings probably got burned up in a fire.

Unfortunately this obvious (highlighted) point is lost on many folks, as they failed to pay attention in science class. This unfortunately bleeds over into other ideas in which getting something for nothing is a key element :).
 
Gotta love the stories about that secret carburetor the oil companies squashed as well. Make the car get 3000% of the available chemical energy out of every gallon of gas. The drawings probably got burned up in a fire.

Well, what amazed me the most is that 40 + years later and I still hear this story from various people every so often.. not including online (which you can look up this urban legend).

But what if this "carburator" wasn't what we'd imagine.. it would implode the fuel and create a cold nuclear fission reaction? It becomes no longer a question of chemical energy but molecular/atomic released energy instead, which this unit would also control the intakes to stay open and synchronize the pistons' movements? A single drop of fuel would then be able to release a ten-fold increase in energy potential...

hmmm...

:p
 
Unfortunately this obvious (highlighted) point is lost on many folks, as they failed to pay attention in science class. This unfortunately bleeds over into other ideas in which getting something for nothing is a key element :).
It shouldn't take too much gas to get your perpetual motion engine running. Your Carnot go?
 
I'm happy to accept removing all water from an edge might help it retain it's sharpness somewhat but the notion that shaving doesn't dull an edge is crazy.
 
But what if this "carburator" wasn't what we'd imagine.. it would implode the fuel and create a cold nuclear fission reaction? It becomes no longer a question of chemical energy but molecular/atomic released energy instead


Bzzt! All the atoms in petroleum products - except the old lead additives - are lighter than iron. Iron is the meniscus of the nuclear binding energy curve. So you'll need a cold fusion reaction to release any energy. If you are fissioning the lead then it will not work on unleaded gas.

OK! EUREKA!!! That's why the government forced us to use unleaded gasoline. To foil the high mileage cars so the oil companies could continue to make huge donations to politicians.

Man, just wait until I tell Batboy.
 
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