stropping compound question

[forrestdweller]

He lives in the jungle?

For outdoor use, you can get one of those polishing ceramic stones.

Some, if not most, Dental hygienists use them to finish their instruments.
One type is flat, about 2 cm x 4 cm or thereabouts.

i prefer the jungle (or at least the deep countryside) but right now i'm for a few weeks in town which gives me the opportunity to use WiFi and catch up a bit... this part of the country is a bit of a backwater, though

interesting idea with the ceramic stones, see if i can find one somewhere (makes me wonder if a ceramic tile could work, too....)

no idea of straight razors still exist -- haven't seen one around here for sure. but thanks for reminding me as i'm slowly begin to look like a Congo (== howling monkey)

 

[demographic]

I bought some fancy green Veritas stropping coumpound for about a tenner a little block a while ago, charged a bit of MDF with it and its spot on.
Then I looked on Ebay and got five or six blocks of polishing compounds for about the same money.
Different colours are reckoned to be better for different metals and finishes but just give em a go and see how you get on.

Mine was mostly for plane blades and so on but the principle is the same.

 

[Janne]

i prefer the jungle (or at least the deep countryside) but right now i'm for a few weeks in town which gives me the opportunity to use WiFi and catch up a bit... this part of the country is a bit of a backwater, though

interesting idea with the ceramic stones, see if i can find one somewhere (makes me wonder if a ceramic tile could work, too....)

no idea of straight razors still exist -- haven't seen one around here for sure. but thanks for reminding me as i'm slowly begin to look like a Congo (== howling monkey)

Nice, plenty of nature around then!

Grazed tiles do not work well, unglazed work, but give a course surface.
The redge on the underside of some porcelain/ceramic cups work too, so does the edge of your car's side window.
But none will give a 'perfect' surface. Sharp yes.

Yes, Straight razors are still made, the best ones in Solingen in Germany. Best shave ever, if you have the ime in the morning!

The Dental/Hygienist ceramic stones give a very nice edge, but not polished. If you see a local dentist, ask him what his hygienist uses.
The smoothest ones are semi translucent white.

 

[Janne]

https://www.hu-friedy.com/instrument-sharpening/sharpening-stones/arkansas-stone-super-fine-grit
That is the stone which I have been using to fine finish my edges is the SSAS 22.

It has lasted me for around 30 years, gentle use. Outdoor knives, kitchen knives until 3 years ago.
I never used oil, but my body’s best lubricant, spit.

I am no ‘mirror shine nerd’ though. It gives a shiny/satin finish, maybe around 2000 or above look?

But my big question would be: why do you need a such ultra sharp edge? Cut wood a couple of strokes and it is gone. The optimal angle for a long lasting useable sharpness ( outdoors) is to large for you to achieve a ‘shaving sharp’ edge.

Do you know how a scalpel blade edge and sides are?

 

[demographic]

Although I have used spit on sharpening stones, I much prefer to use plain water. Its just nicer all round. Especially when I lend a sharpening stone to someone else, I don't want some minger groching all over it then handing it back. It has happened and I'll be honest, I had a bit of a sense of humour failure with the person who did it.

There's some pretty exhaustive research about how many strokes you can get out of plane blades made from various steels and another one thats been researched is blades used for bookbinding.

Ive never seen any research into bushcraft knives thats come even close to the two studies Ive seen for plane blades and bookbinding knives as far as being scientific and most of all, repeatable.

If I remember right M4 high speed steel came out at or close to the best for longevity in both tests.

 

[Robson Valley]

In theory and in practice, you must have enough steel to support the edge in application. No mumbo-jumbo.
Don't expect to baton wood with a scalpel. Scalpels are for meat cutting. The bevel angle is too fine and the steel is too thin.

I have measured the total included bevel angle on every wood carving tool that I have bought in the last 25 years.
Those angles range from 30 degrees to 12 degrees. They all must be made "carving sharp."
That's not something needed for splitting firewood. A splitting edge is not a cutting edge.

 

[Janne]

I think that today the young Gen expect the one knife to be a tool for all uses. From carving spoons and feather sticks to batoning.

The steel manufacturers today have invented some cool stuff, powder steel alloys and such, with immense hardening abilities, toughness, you name it.
But, as you rightly write, the edge angle is what matters most.

Many modern knives are incredibly thick, to give them strength so they can be used to baton. This gives an edge that has a much to big angle.
Those owning blades thick 4mm or above, try slicing bread.

Some years ago, I bought a Fällkniven A1, went out on a weeks trek in the Scandi mountains.
I struggled. Have not used it since. POS, total waste of money.

 

[demographic]

Fair comment on the included angles, have a look at the difference between the included angles of something like a mortice chisel to a paring chisel.
The mortice chisel is hit with a hammer or mallet and chops across the grain and sharpened to maybe 35 degrees or so, but a paring chisel never gets hit with a mallet and it slices a small sliver off something like 15-20 degrees.

Expecting something that battons well (kind of mortice chisel usage) to be a good slicer (like a Paring chisel) is a big ask, the metal can manage it if theres big enough included angle but at very acute angles theres not enough edge support for battoning.

Sometimes the lesson is, if youre experiencing edge failure on a particular task, sharpen it to a bigger angle till you don't.
Or use an axe.

 

[Robson Valley]

I have been carving western red cedar for many many years. Very soft wood you can dent with a fingernail.
I can only describe it as like thin slicing a very over-ripe tomato = my edges must be thin and beyond shaving sharp.
Straight and crooked knives are 12-15 degrees. The D and elbow adzes are all 25 degrees.

Edges always fail. I can see that with a 10X magnifier and a bright light.
In practice, I can feel the edge going away after 20-30 minutes steady carving in WRC.
4 swipes on the strop with honing compound is usually all the restoration required.
I've been using a mixed stick of AlOx/CrOx for many years. It is adequate, I need look no further.

In my family's west coast logging business, axes for cutting were always 30 degrees (softwoods).
Splitting axes was usually 40 degrees AND the sharp edge was filed back maybe 1/4 mm.
This allows the wood to split apart ahead of the steel which then acts as a wedge.
"Carving axe" seems such a contradiction in terms to me.
So what's your axe used for?

 

[Nativewood]

I remember a 'one-knife-for-all' style challenge on here a looong time ago. It involved @British Red and another fella whose name I think was Jonny. BR had his utterly gorgeous Precision Field Knife and Jonny a Fallkniven F1. Both chaps are clearly very skilled knife users and all was pretty even between the two blades till it got down to the carrots. Naturally the F1 was expected to crash and burn but you should have seen the rice paper thin slices Jonny managed with that F1. Man, I still lust after that knife of Red's...

 

[Janne]

I have an F1 too. Much, much better knife. If I was allowed only ONE knife for the rest of my life, that would be the one.
Only negative ( for me) is the wide/high blade, but that I could get used to.
I bought the model with the black blade.
If I ever bought another one I would choose the non blackened blade.
The coating scratches and looks really horrible!

But, as this thread is about stropping, the VG10 edge material is a pig to sharpen.

 

[Janne]

I checked a scalpel blade under mild magnification, and the edge has striations at an 90 degree angle to the edge. No doubt the edge is vast/ saw like. Maybe that is the secret to the smooth meat cutting .

I also checked a couple of suture needles, those seem to be chemically sharpened? Kind of smooth but not polished surfaces.

First time ever I check these items under magnification, despite a daily use!

I wonder if a normal knife would cut better if it is honed ( say - 2000 grit) to achieve these 90 degree ‘scratches’ compared to a high gloss polishing?

 

[Robson Valley]

Again, what do you propose to cut?
Sharpening to 1,500 grit then honing on a strop with AlOx/CrOx compound is about as good as it gets.
Study the scanning electron microscope pictures in Leonard Lee's book for objective evidence of that.
Has saved me no end of effort doing what I used to think was useful "sharpening."

Is the edge coarsely shredded or finely shredded? Which is useful in the application?

Scalpel blades get machine sharpened then laser inspected. Hypodermics too.
I can see chemical corrosion for suturing needles.

 

[Janne]

RV, any idea why clean leather works? You might be grown up enough to remember when hairdressers used to shave customer's faces with a straight razor? And honed the edge on a leather flap or paddle?

 

[Robson Valley]

Years ago, I tried to find out the truth to using plain leather as a strop.
I've seen it done, I know it works very well.

Daily dust and grime on the leather was one answer. I know that works as I wipe my gouges on my gloves!
Another answer(?) was that the tanning process introduces chemicals which precipitate as crystals hard enough to scratch steel.
Nice idea but not all tanning processes are the same.

Gradually, I began to re-read the same opinions day after day so I quit.
If it has been investigated with any measure of science since then,
I have not looked for it.