Hesitate to ask a sharpening question

[Patrick Chase]

For the mother god , what's happened to the simple approach within woodworking.

It was killed off by people who do things like obsessively searching for a "true" 0.5 um Chromium-Oxide paste as opposed to the adulterated stuff LV sells.

Face it, we're all too clever by half, with the possible exceptions of Warren and George. Even you.

[Malcolm Schweizer]

Not many people know this, but in the atom bomb is a PMV-11 iron so well-sharpened that when the bomb hits the ground it splits an atom. Einstein used waterstones at 1,000,000 grit to achieve this. This photo shows Einstein calculating the bevel angle with and without the ruler trick. The bottom right calculation is believed to be the true grit of Lee Valley's green chromium oxide. Sadly, he died before finishing that part of the equation, and it seems we will never really know.

image.jpeg

[Jim Koepke]

Do you sharpen her kitchen knives? It may be difficult to convince her to sign off on a $500 stone, but $150 might be seen as a reward to a good and faithful servant, especially if the money was used to make her job easier.

And then there is the sneaky approach. Save pennies away from her eagle eye. Buy the stone in time. Lose the receipt. Lose the new box. Treat it like you have owned it for years. Unless she is sharper than most non-woodworkers, she will not notice. Kinda like leaving the house to go to the gun range with an empty gun case, and returning home with it not so empty.

Stan

She complained one time after sharpening our knive that they were too sharp. She has since changed to requesting a warning when they are sharpened. I tend to use knives more than she does. She used to use a serrated knife to make a mess out of tomatoes. Now it is usually my job to do the chopping of vegetables or slicing meat.

In a way my pennies have been stashed away saving for something. Just haven't quite figured out as of yet on what it is they will be spent. Shame on me, a bandsaw with 12"+ resaw ability would get my attention.

jtk

[Patrick Chase]

Sorry, I didn't notice this until now...

This is interesting and agrees with the specifications in the (current) Norton 2015 catalog:

http://www.nortonabrasives.com/sites...ed.pdf#page=52

What is strange is a chart from 2007 puts the Norton 8000 water stone at 1.2µ particle size.

The question is was the 2007 chart in error or has Norton changed their stone? (error more likely?)

Every source I've seen (including pre-2007 ones) has that stone at 3 um.

Plenty of people get good results for woodworking with the Norton, so if it's working for you then I wouldn't worry about it. If you want to try a higher grit on a budget then one option might be the MetalMaster 10K resinoid mystery stone, which leaves very nice edges and looks and feels suspiciously like the "Ohishi" 10K stone that L-N sells. The only caveat is that both the MetalMaster and Ohishi/L-N 10Ks are soft even by polisher standards, so you have to be a little careful if you use freehand "push" strokes.

One thing I didn't go into in my previous post was variability: The roughness of the edge is determined at least as much by the maximum abrasive particle size as by the average. It's possible that Norton has particularly good control over size distribution (they certainly meet tight distribution specs in their diamond pastes) in which case the nominal may look worse than the reality. Then again I suspect that Sigma, Shapton, Imanishi, and Naniwa also know a thing or two about distribution control, so I doubt Norton could be all *that* much better.

[paul cottingham]

Not many people know this, but in the atom bomb is a PMV-11 iron so well-sharpened that when the bomb hits the ground it splits an atom. Einstein used waterstones at 1,000,000 grit to achieve this. This photo shows Einstein calculating the bevel angle with and without the ruler trick. The bottom right calculation is believed to be the true grit of Lee Valley's green chromium oxide. Sadly, he died before finishing that part of the equation, and it seems we will never really know.

image.jpeg

:-)

Funny, cause I often say that you know a blade is sharp when you can hear the air popping from the atoms being split when you move it.

I'm the funniest guy I know. Try to hold your applause.

[Patrick Chase]

Not many people know this, but in the atom bomb is a PMV-11 iron so well-sharpened that when the bomb hits the ground it splits an atom. Einstein used waterstones at 1,000,000 grit to achieve this.

Funny, I heard he used a very early prototype Cho10K. That's why some crazy people are willing to spend almost $300 for a ~2 um stone.

(yes, I remember exactly what you had in your $10 high-end K-Mart water stone storage solution. I have a Snow White and think that the Naniwas perform a bit better than their nominal abrasive size suggests, so this is purely a cheap snarky shot on my part)

[Patrick Chase]

:-)

Funny, cause I often say that you know a blade is sharp when you can hear the air popping from the atoms being split when you move it.

I'm the funniest guy I know. Try to hold your applause.

Groan. It took me like 5 minutes to get from "air popping" to "hair popping". Must be getting old...

[Malcolm Schweizer]

Funny, I heard he used a very early prototype Cho10K. That's why some crazy people are willing to spend almost $300 for a ~2 um stone.

(yes, I remember exactly what you had in your $10 high-end K-Mart water stone storage solution. I have a Snow White and think that the Naniwas perform a bit better than their nominal abrasive size suggests, so this is purely a cheap snarky shot on my part)

In my defense, it was a "curiosity killed the cat" moment for me, and I only paid $200 on eBay. :-)

[Brian Holcombe]

I would enjoy seeing every sharpening thread strung together.

I fully admit that I am part of the problem!

[Stewie Simpson]

I would enjoy seeing every sharpening thread strung together.

I fully admit that I am part of the problem!

Not so Brian; a lot of what you mention can be best described as part of the solution within developing a consistent sharpening technique.

regards Stewie;

[William Fretwell]

Going back to the OP's question, which is a good one; deciding where to spend your money to reach the point of no return!
It would seem that when you can strop on leather or MDF or paper or the leg of your jeans rubbed with some green stuff at almost zero cost going over 8k is not an investment.
We poor simple folk may have to sharpen every 5 minutes instead of every 7. We need to decide if charging our strops should be done with flat side or edge in simple zig zags or figure 8. Do we use a hair dryer for added bonding?

I for one am relieved to have reached my point of no return. The money 'saved' on the 15k stone can be put to good use buying wood.

[Brian Holcombe]

Haha, part of the solution! I like that thought.

WRT stropping, during Kezuroukai it became apparent that stropping my blade was causing me a disservice and I ditched the approach. I like stropping for knives, and double bevel tools, or gouges.

Stropping is a double edged sword, on blades where you cannot quite get the wire edge off, or if you aren't quite removing the wire edge for some reason, it will be a dramatic improvement as the strop will no doubt remove the wire edge. If you are already removing the wire edge, then there is no improvement to be made and in my experience the quality of the cut slightly declined when stropping.

The best thing (IMO) you can do is learn to see an edge that continues to show wear, and learn to feel for a wire edge, or burr and to know when it is removed. You can use magnification for this, but the most practical approach is to train your hands to feel for the edge.

The number one culprit for retaining a wire edge is likely not grinding back far enough when refreshing the edge, remove the wear completely with your rough stones before progressing through the grit. I like to work the back very lightly after each grit on the bevel to ensure that I've removed edge, with each new grit it is reformed and removed again.

The result is a very long lasting edge, partially because it is without marks from the previous grit (coarseness) and partially because it is completely repaired of previous wear. A true fresh start, so to speak.

Once you have a basic regimen of sharpening stones, improvement of process or chasing ideal in process are going to create better and longer lasting edges than continuously purchasing additional stones.

[Tony Wilkins]

I have finished out on an 8k stone since I started - first King and now Suehiro dual-stone. I had a thought and just got a sheet of PSA backed diamond film at .5 micron for the few tools I want a sharper edge on. Haven't used it yet so can't say how long it might last.

[Patrick Chase]

I have finished out on an 8k stone since I started - first King and now Suehiro dual-stone. I had a thought and just got a sheet of PSA backed diamond film at .5 micron for the few tools I want a sharper edge on. Haven't used it yet so can't say how long it might last.

Assuming it's 3M 668X (which is very likely) it'll last quite some time if you take care of it. It's easy to gouge, though, so be careful with "push" strokes. Also make sure to remove any really big notches/burrs/etc on coarse/medium grits, as they can rip the coating on 0.5 um film. The coarser-grit films are more resilient, but I prefer a coarse cheap-ish waterstone [*] or diamond paste on 1018 steel plates for dealing with truly nasty burrs/gouges/etc.

[*] Something that costs less than $1 per mm thickness, like a Bester 220 or Cerax 325. Nastily dinged-up tool steel will leave gouges in almost any sharpening medium, so you'd might as well use something cheap.

[paul cottingham]

Groan. It took me like 5 minutes to get from "air popping" to "hair popping". Must be getting old...

Funniest. Guy. I. Know.

At at least my mom always said so. :-)