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On the Measurement of Croap Durometer: A New Methodology

I would think both would need to be securely clamped but how to measure the force required with that tool?

Something like this more what I envisioned.

https://www.amazon.ca/Tensiometer-Professional-Measurement-Workshop-Supplies/dp/B08J8K142X/ref=sr_1_21?_encoding=UTF8&c=ts&dchild=1&keywords=Force+Gauges&qid=1603978296&s=industrial&sr=1-21&ts_id=11853271011&th=1
Interesting. I've never seen one of those. Do you pull on that needle? It looks kind of like a very sensitive version of a fishing scale, where you hang the fish off of it and it gives you the weight. How would you affix it to the blade?
 

Esox

I didnt know
Ambassador
Do you pull on that needle?
Thats the question. I looked in the description but didnt see any mention. I didnt look very hard though.

Peak compression on this one.


So that would measure force applied, but not distance of travel. That should be easy enough though.
 
Thats the question. I looked in the description but didnt see any mention. I didn't look very hard though.

Peak compression on this one.


So that would measure force applied, but not distance of travel. That should be easy enough though.
That thing is awesome! Looks expensive, but it could multi-task as a dovometer, so it'd still be a bargain. 😋

Here is cool idea on how to measure the distance travelled. A handy, dandy dial indicator gauge. This would work with a type D durometer as well. Make the dial indicator push the force gauge down, and it'll measure distance travelled in 100ths of a mm.

Alternatively, you could just remove the dial indicator, replace it with a type D durometer, and lower it until you saw light between the blade and top cap.

I've got one kicking around in my basement somewhere that I used for setting up my woodworking woodworking tools.



 

Esox

I didnt know
Ambassador
That thing is awesome! Looks expensive, but it could multi-task as a dovometer, so it'd still be a bargain. 😋

Here is cool idea on how to measure the distance travelled. A handy, dandy dial indicator gauge. This would work with a type D durometer as well. Make the dial indicator push the force gauge down, and it'll measure distance travelled in 100ths of a mm.

Alternatively, you could just remove the dial indicator, replace it with a type D durometer, and lower it until you saw light between the blade and top cap.

I've got one kicking around in my basement somewhere that I used for setting up my woodworking woodworking tools.



That was my thinking yeah, something along those lines. Theres also these but dont ask the price! lol

Dillon Force Measurement - U-Force - https://www.dillon-force.com/products/force-gauge-mechanical/u-force.html
 
If I was to buy a type D durometer to measure rigidity in razors, what do you think a testing setup would be. It seems like just holding a razor in one hand and a durometer in the other would lead to measurement errors. Razor in a vice, and durometer in hand? Some kind lowering device?

@ShavingByTheNumbers
Hey, Nick. It seems that what I wrote here earlier got overlooked...

Instead of a durometer, what one would really want to try is a force gauge/meter. You might be able to get an appropriate one for the task at a good price. However, my thinking is that a force gauge/meter would not be sufficient for getting the job done properly in all cases, possibly even most cases.
Measuring the force it takes to cause separation between the blade and cap is not so easy, but you might have success. First of all, the blade itself makes a difference because blades vary in thickness and width, so using units of the same blade or just one blade, if possible, would be good. Next, the application of the force matters. Is it going to be applied at a "point" (small zone) along the blade cutting edge? If so, you'd get different results for different locations, and part of the blade would probably still be in contact with the cap as you notice the "point" being pushed off from the cap. Trying to distribute the force along the blade cutting edge might be best. That would be done with a stiff straight edge (flat or rounded) pushed against the blade cutting edge. Maybe the stiff straight edge could be fixed to the force gauge to replace the "point" contact. Your question about the razor in a vice makes sense. You would want the razor safely fixed in place as you safely push on the blade cutting edge. For safety purposes, maybe there should be a thin wide guard area between the stiff straight edge and the force gauge so that if the stiff straight edge slips off of the blade cutting edge, the guard, instead of your hand or body, would make contact with the razor and/or blade. I hope that eyeballing the loss of contact between the razor and blade would be sufficient. A backlight might prove useful so that you see the backlight as the space between the razor and blade grows from nothing. That would be your visual cue to stop pushing. The force gauge would hopefully keep track of the maximum force reached to accomplish your goal, but even if it did that, you might find it best to video the process and check the record. You could vocally indicate when you see the separation and get the force at the moment from the video.

Those are my thoughts on how you might do this. I hope that they are helpful. You can check Amazon like I did for force gauges, and there are other places that sell them, too, like McMaster-Carr.
 
Behold!!!

I give you the dovometer! Here is a picture of it in the relaxed position with no pressure:



It's a ball point pen, with the spring removed from the bottom half of the pen, and then the spring is inserted into the top half of the pen. The ink tube is then inserted on top of the spring. A millimeter ruler is printed to scale on paper, cut out, and taped on. The firmer the soap, the more mm of spring depression you get.

It actually works!!!

Arko was the first one measured by this miraculous new device (naturally) Here are the first 4 measurements:

Arko: 11 mm
Haverford: 4 mm
AGAR: 2mm
Arcadia: 1 mm

Here is it taking a reading of Arko.

Part time Genius, quite the imagination!
 

Chan Eil Whiskers

Fumbling about.
To meet the annual continuing education requirements of my BOSC membership, it is necessary for me to either:

1. Advance the science of shaving in some extraordinary or dubious way
2. Provide evidence of unrepentant indulgence in one or more acquisition disorders.

Unfortunately, my spouse has recently discovered the 10'x10' storage unit I've been renting for my shaving necessities, so the latter is not an option at present. Therefore, it must be science.

One problem that I think worthy of study is the firmness of various cremes, croaps, and soaps. Some cremes are firmer than croaps, and some croaps are harder than soaps. Mitchells Wool Fat soap is the only known material harder than diamond. It's gets downright confusing. This would not be an issue if no one cared, but studies show that 0.03% of shavers have a strong preference for a specific degree of firmness in their soaps. Shamefully, manufacturers offer little to no information on this key parameter. It would be helpful therefore to have an easy, repeatable way to measure the firmness of soaps, such that any hobbyist soap hoarder can measure the firmness of soap/croap for the purposes of posting more edifying reviews to this message board.

It's a vexing problem, but fortunately we may stand on the shoulders of giants; the rubber and plastics industry has devised such a tool, which is called a durometer. I have used these devices myself, and find them indispensable. It is a simple tool, that consists of a "needle" affixed to a spring. The tool is pressed down on the material to be measured, and the shore durometer is displayed on a dial indicator. The OOO Scale Durometer would be perfect for this purpose, but sadly many wet shavers do not have this tool in their shaving den.



Thus a new methodology must be devised. I believe that this new methodology should have the following characteristics:
  1. Measurement should be on an interval scale (not ordinal or nominal)
  2. It must use only household materials costing in total no more than $1.00
  3. It should be possible to make the measurement apparatus in less than 5 minutes
  4. Individual measurement should take no more than 10 seconds
  5. Accuracy must be +/- 13.7%
Sadly, I have no such methodology, nor do I have any good ideas on how it might possibly be done. Please help.
This is obviously the most important thread in a very long time. Congratulations to the OP.


1604158923757.png

Big Nurse - you may not be aware she reads all B&B posts, and I do mean all - pulled me aside today. For once she had something useful to tell me.

No, it wasn't that I needed my medicine and was scheduled for another round of ECT.

Her suggestion was a tutorial on how to correctly purchase and use a durometer. Apparently she once used a tire durometer, back when her hobby was weekend drag racing. Or maybe it was when she was into going out in drag on the weekends. I got kinda confused. I think she said a tire durometer would or wouldn't work for croaps but maybe she said it might work. Sorry. It got a bit fuzzy, but you know how the voices can be.

Anyway, they sell these things on eBay but I don't know which one to buy or how to use the tool. Obviously I have to have one not that I use croaps or creams unless Vitos Red counts which I say it doesn't but anybody's better off with the tool which they don't know they need until they have one.


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Now that we know about them we can think of all sorts of uses for a durometer. Everyone needs one, at least one. Ebay has 'em.

This is crazy good.

Happy shaves,

Jim
 
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