A question on historical sharpening.

[Janne]

Better to fix stones and run the edge on it.

You can run the stone along the edge, this was done by every farmer and farmer’s wife since the scythe and sickle were invented.
Soft bad steels, freqvent sharpenings. Running the stone at 90’ would maybe remove to much steel?

 

[Robson Valley]

A fixed stone and a running edge is fine for long straight edges.
Many other times, the reverse is the best. Ever sharpen a shovel?
A thousand tree planters can't be wrong. Green end up, kids!

No excess steel removal. Go gently! You watch. Every time, the sharpening stroke is at least a diagonal.
No. Here we hold the crooked knives stationary and run the stones across the carving edges. Same as with an adze or axe.

I will admit that it has taken me some time to hold a crooked knife over my knee and sharpen/hone in just a few strokes
at a constant, fixed and known bevel angle.
No complaining. If I can, anyone can. Just takes practice. And more practice.

 

[Hammock Hamster]

Another early fault of my sharpening technique:
I was running the stones along the edges. Parallel to the edge. Don't do that.
I learned that the scratches from the abrasive allowed the edge to fold up like the flap on a postal envelope.

Holding the needed bevel angle, the abrasives have to run out at right angles across the edge.
Means a lot of short strokes with a small stone and a bigger risk of getting cut. Gloves?

The jiggling about was more down to me trying to get the whole thing in shot before I lost the light but yes the knife will be secure normally.

I'm trying to get a mental image of what your suggesting with short strokes and right angles, would I be right in saying with the small stone you would sharpen the blade one stones width at a time and draw the stone towards the edge?


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[Janne]

Same technique as you use on Japanese stones you can check on Youtube.
Of course, even using a rotating sharpening wheel you too do the 90* angle.

I personally prefer to have a fixed or immobilized stone, and move the blade as it is less risk of cutting yourself

 

[Robson Valley]

Yes. One stone's width at a time, more or less. I find myself using diagonal strokes but crooked knife blades are never more than 3" long.
The real PacNW blades are sharpened on both edges for right and left hand use (like a Mora/Frost #188) so the cut risk is bigger.

I did fold quite a length of knife edge one time. I could see it with a 10X magnifier. Very fine.
I can only guess that it followed a deep abrasive scratch parallel to the edge.

 

[petrochemicals]

As promised I spent some time experimenting with different stones today in a sort of quasi experimental archeology.

No idea what they are except the slate though I think one may be granite and another hard sandstone - answers on a postcard please.

So I decided to try a bit of lapping with some sandpaper and diamond stones on lieu of having a flat rock to try and get a better sharpening surface.

I won’t lie, it was bl**dy hard graft but simplicity itself just working the stones back and forth.
I realised pretty early that the stones need to be wet which makes the lapping much easier and helps create a slurry (a bit like Japanese water stones) that I think helped the process.

All in all I’m pretty pleased with the results and trails on a few blades are encouraging, the flattened sides were pretty small due to my poor choice of stones but it’s a learning experience for me.

Next step is to find some flatter, wider and more even stones (long flat ovals feel like a winner).

Anyway hope you liked the pics.

Hamster


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You lunatic, that must have taken hours. Also now that you have done the flattening, may I be the first smunt to point out that they did not have diamond stones in the past.

I never have believed in slurry on stones other than for polishing.the slurry is loose and only gets in the way and wastes your energy grinding it into smaller and smaller pieces. I do not know why water works but I cannot stand dry grinding. Also years ago I read on british blades that there are places where a circular stone has been cut from the face of a cliff and the negative shape is still visible from years ago. Try and find a piece of sandstone or cut yourself one.

 

[Hammock Hamster]

You lunatic, that must have taken hours. Also now that you have done the flattening, may I be the first smunt to point out that they did not have diamond stones in the past.

Ha, right on both counts though I should mention that I didn’t have a suitable flat rock to hand and if I did it would have taken sooooo much longer!



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[Robson Valley]

The sole purpose of the water is to flush the swarf off the surface of the stone so that fresh grit of known particle size is always exposed.
The "slurry myth" is exactly that = smoke & mirrors. The same is true for oil, not a "lubricant" in the least.
ref: The Complete Guide To Sharpening. 1995. Leonard Lee. ISBN: 978-1-56158-125-2

I think that the greatest chase is for stones of suitably small and consistent grit grain particle sizes.
River stones are OK for one-off adventurers like us. Sooner or later, somebody finds the bedrock
that has economic value.

 

[demographic]

Some slates are worth a bash, as they are basically a metamorphic mudstone.
plus you can get them in 20" by 10" sizes, they have a natural cleavage plane so can be split to flatness.

As discussed HERE

 

[Tengu]

I found a few stones at the car boot today.

All sizes and grades. A few artificial and doublesided.

Many are small, orange and labeled `No 61 fine India`

recognise them?

 

[Robson Valley]

I've heard of "Fine India" sharpening stones but don't recall ever having seen one.
Are they quite "glassy-looking?"

I have most grit grades of sandpapers from 36 grit up to 1,500 grit and 2k and 4k water stones.
I know this is totally subjective = I shut my eyes and feel the unlabelled stones and sand papers with my finger tips.
I'm guessing grit size and I'm happy to admit it until something 10X better comes along.

So, one artificial 2 sided stone had to be about 80 and 120. Another one seemed to be 120 and 220. So be it.
They are for reshaping and repair. I don't start any wood carving edges with less than 600, usually 800 and up.

Just looked into Norton's updated abrasives catalog. Fine India is about 320 grit to them.
See if this link works:

https://www.nortonabrasives.com/sit...cument/Catalog-SharpeningStones-Norton200.pdf

 

[Tengu]

https://www.ebay.co.uk/itm/India-FS...652466&hash=item5d7ded39cd:g:rnEAAOSwPHxbDVqL

Something like this but mine is 8cm long

 

[Robson Valley]

Norton Stones, but you still need the catalog to find the actual grit size.
8 cm would be OK but I have dreams of stones in the 10-15 cm range.

There's an international code of numbers and letters to tell you about the grit, the binder, the maker, all sorts of details.
Translation in on page 38 in Lee's book (#48, above).
Descriptions such as "Fine" and "Medium" are hard to apply to carving gouge edges.

I'm still keen on using river stones if I can find tumbled and smoothed stones in our glacial rivers.
The water is still up in the bushes and running like Hello so I expect to wait until August, if that.

If I do find something but bigger, I won't hesitate to trim the rock with a diamond saw and an angle grinder.
Could save me several years of hand work?

 

[Billy-o]

I picked up an Arkansas stone years ago ... not big, about 4" and cheaper than cheap. It has been very handy for coarse touchups. Otherwise, I just use a big diamond stone now and abrasive cloth ... or a Sharpmaker

I have some Japanese stones which are great and I love to use them, but they are such a great big fuss. So, they only come out if I am planning to sharpen everything, including the dog

 

[Robson Valley]

This natural stone/historical sharpening thing appeals to me because I carve with Pacific Northwest style tools.
Just about everything, adzes and knives, have sweeps to them = they are all curved edges.
I don't use more than 1 or 2 knives with straight blades and they are no more than 1 inch edges.

http://kestreltool.com/index.htmlhttp://kestreltool.com/index.html

That should show you what I use. Maybe 2 dozen crooked knives plus several adzes.
I have a bunch of good water stones that I used for years. They are boxed, under the bench.

I have a draw knife and several spoke shaves as the rare straight edges that I use.
I can cope easily with all the carving gouges that I've been using.

I've switched to sharpening and honing everything with fine sand papers, both flat and wrapped on mandrels.

 

[Janne]

Interesting about them using curved edge tools. Must be a recent custom?
Using imported steel, so maybe a couple of hundred years?

I assume their artworked took a leap in designs with them aquiring steel tools?

( sorry, so many question marks, but I interested..)

 

[Robson Valley]

We know for a fact that people were living in BC coastal villages at least 14,500 years ago.
By the time of European contact, the Haida, for example, were familiar with iron for fish hooks and small blades.
It became apparent that as metallurgical skills developed in Asia, metals were delivered across the Pacific by the Japan Current.
There would not have been sheet metal but fixtures and fastenings of small sizes.
We still get crap from Fukushima (nothing very radioactive) and the concurrent tsunami wreckage.
It's considered also possible that untraceable (?) traders from China and Russia may have brought iron as well, pre-European.

Any or all of that was a driver for shaping and sharpening. That, of course, meant the search for abrasives.
Explorers noted that the proliferation of art and carvings expanded dramatically with the ready availability of large amounts of iron.

Even in this day and time, many First Nations children apprenticed to carvers make their own tools. A simple expectation.
Segments of truck leaf spring make ideal elbow adze and D adze blades. Small mill files are forged into carving blades.
Off the grid, without electricity, you can bet that all the hand finishing abrasives were particular found stones.

I have some such stones. I tried them and found them to be too coarse for carving but fine for kitchen work.

 

[Hammock Hamster]

Well a quick update, after some playing around I have found the factory edge of the Bowie to be woefully inadequate for my needs, to the point it won’t carve feather sticks which I believe every knife should be capable of.
To that end I have decided to use modern stones just once, in lieu of a somewhat traditional grindstone, to sort it out.

I decided to use the Lansky to give me better control over the reprofiling and decided on a 30 degree angle which should give me a good toss up between a cutting and chopping edge.

It’s a work in progress because boy is there a lot of steel to get through, I’m debating whether I leave the front half unchanged just for chopping and use the back half for all my cutting needs - anyone know if there’s any historical evidence of this type of thing (I’m sure I’ve seen references somewhere but I can’t for the life of me recall where.

Here’s a bit more of a close up showing the change between profiles.

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[Robson Valley]

What do you suppose was the factory bevel? 40 degrees?
Do the whole edge with one included bevel angle.
If duals had any true advantage, everybody would be doing it.

What a grunt! That's a loooooooong edge to revise. Good luck with it.
I'm so impatient that I'll hack down a 25 degree edge to approx 12 degrees with a chainsaw file.
Then do the finesse work.

Carpenter's & woodworking planes are usually 30 degrees, like many types of chisels.
Top quality, brand name wood carving gouges are all 20 degrees, like most good kitchen knives.
Dedicated wood carving knives are all in the 12 - 15 degree range.

If I had to pick one do-all total included bevel angle for a bush craft knife it would be maybe 25 degrees.
30 is a blunt angle to push wood open but there's enough steel behind it for the heavy bashing.
20 would make as many fine feather sticks as you might need but the edge will swear down more quickly.

 

[santaman2000]

......Holding the needed bevel angle, the abrasives have to run out at right angles across the edge.
Means a lot of short strokes with a small stone and a bigger risk of getting cut. Gloves?

I always move the blade as if I were trying to cut a thin slice from the stone. Just like they taught in the Boy Scouts way back when. (And what Daddy taught too)