Honing pressure on a JNat

[rockviper]

According to Iwasaki's booklet on honing, I read on page-16...

However, if you gradually reduce pressure as you hone, a Kamisori can take an excellent edge. So hone Kamisori in the following way, reducing pressure as you go: (1) Coarse honing - Botan Nagura - 4 Kanme 500 Monme (16.5kg) (2) Middle honing - Tenjou Nagura - 450 Monme (1.65kg) (3) Finishing - Tomonagura - 45 Monme (165g) (4) False Edge removal - Raxa hone - 45 Monme (165g) (5) Edge Finishing - Honyama Hone - Weight of the razor

I follow only the first three progressions (Botan, Mejiro, and Tomo), but don't use anywhere near the pressure for the Botan and Mejiro/Tenjou that they indicate here. I've been using very light to no pressure during all my stages. Am I out to lunch?

 

[buca3152]

No. Pressure magnifies the grit. So I think if you spent more time on those naguras, it would equate to something similar. Over 30 lbs sounds like a lot. Iv never tried what I think would be even close to that. I would imagine an extra hollow(he was talking kamisories though) would flex with that amount of pressure.

 

[Steve56]

There was a discussion about this in the thread on the "Iwasaki honing guide revisited" thread IIRC, and the conclusion is the pressure is too much for a lot of razors. If you put 30 pounds of pressure on a full hollow, the blade will flex and you'll be honing halfway up the blade.

Cheers, Steve

 

[rockviper]

Indeed, I re-found that thread after posting and am now working my way through it. Great vids there as well.

 

[jpcwon]

^^^what they said....I have found that I use firm pressure on Botan, moderate pressure on Tenjou, and progressively lighter pressure on Mejiro and Koma. Beu even my firm pressure is nothing crazy. Nowhere close to 30 lbs....

 

[french connection]

All I can say is that my former father in law was honing razors , especially japanese for more than 50 years..... he used to say "enough presure to guide & hold the blade, never add extra pressure.... I think he was right as I have been using one of these 1880 1900 razors for more than a year (100 110 shaves)....and no need to hone.... just 10 passes on the strop after each shave ....and the razor is still perfect even if I can't use it safely now and I'm forded to store it ....

 

[Gamma]

I believe there are a few things at play here.

First - the translation of archaic measurements - and the translation of the booklet overall.
Also - we're talking about a different time/space continuum here - lol.
Different stones, different techniques, etc. For example - we don't know what base stone the Botan, or any other, Nagura was used on.
So - it's probably best to not take things literally. Iwasaki spoke of this pressure being able to rock a house.
I don't doubt that there was a technique that incorporated that style. I serously doubt he just made that up out of thin air.

Coming out of the gate with good pressure on Botan achieves excellent cutting properties.
This level of cutting will slake off more quickly than expected. But that level of cutting may be desireable.
Remember - honing Kamisori is different, we don't want to wear away too much soft iron on the Omote.
So - it might be advantageous to used higher cutting capability inititially and get past that quickly.

Simply looking at Nagura as 'it breaks down' - leaves you short on understanding and the ability to develop a well rounded technique.
How to use that breakdown is part of understanding the stone/s.

I wouldn't be so quick to dismiss the original numbers; but more than just following what appears to be a recipe I tend to see the approach more a 'concept' and take it from there.

Leaning on a Jnat with 30 lb seems ridiculous - and scary. But it's really not.
There was a thread on this here on B&B not too long ago actually.

I've put what I judge to be around 25-30 lb of pressure (espresso tamp reference point) and the 'cut' was outstanding.
So was the 'break' - this is what it's all about.

A stupid hard stone is, IMO, a requirement. And not worrying about breaking something is also required.
I would not be doing this on a FH western blade anytime soon.

 

[rockviper]

Sounds good to me, folks. Sometimes confirmation of what one is doing can be just as valuable as learning something new. Appreciate the feedback.

 

[Steve56]

I have to question the numbers or the translation of the numbers. Here's why. Attached is an image of not the latest hone, but a lead brick. Yes, a leftover from the old days when I used to use a pair as bookends until the IH people told me that probably wasn't the best idea in the world.

It weighs 26 pounds, less than the 30 pound number. Imagine sitting more than that on your razor. If it didn't break it outright, you'd never be able to move the razor on the hone. If for sake of argument, a razor bevel and the honewear on the spine are both 1/16" wide and 3" long, I end up with 3/4 square inches contacting the hone. If I put 30 pounds of pressure on 3/4 square inches, that's 40 pounds per square inch, almost a large sack of Quick-crete.

Doesn't make sense.

Cheers, Steve

 

[inspiringK]

I don't really hone on naturals, but I don't think that distinction is overly critical here - or maybe it is, I mention the fact so you can decide.

I feel like I press hard onto the stone when sharpening knives, especially at the lower grits. When I used a scale to measure the force I am using on knives, it measured in at 6 pounds. I can't imagine using that much force on a razor, much less using 30 pounds of force, the blade would snap.

The idea of slowly decreasing pressure as you get closer to finishing is good theory though and I think it is something that most of us use.

 

[Gamma]

That passage is about honing Kamisori - not western razors or knives.

I've put a good 30lb on the stone with a very heavy grind blade - the world didn't stop spinning.
Even though the translation of the numbers may possibly be off - the reference about 'shaking the house' in the booklet speaks to very heavy pressure regardless of the actual numbers.
Or maybe the houses were flimsy? Lol. I don't think that's it.

Granted - the quoted pressure is way more than I think I'll be using regularly on any blade anytime soon but in practice it can be done.
At least - I'm using an internal gauge that I also use to tamp espresso and comparing it to that.
I wouldn't do it with a full hollow or on a very soft stone though.

 

[duderdo]

On the one hand I'm inclined to trust a guy who, from what I understand, lived and breathed this stuff.

On the other hand I just honed a Kamisori for the first time recently and didn't use anywhere near that amount of pressure? My guess is I used 2-3 pounds of pressure on botan..

 

[Gamma]

I've not felt a need to take much material off any of the Kami's I've honed actually.
But - the theory is interesting and, I think, it speaks to a critical part of the process.
It's easy to dismiss the numbers - I did inititially, still do to some extent.
My feeling is that there's more to all of it than what meets the eye.

 

[rockviper]

Okay, here's a dumb follow-up question pertaining to the Omote:Ura ratio. Let's say I am executing a 10:3 set. Is this 10 with the Omote "up" or 10 with the Omote "down" (i.e. on the stone)?

I've been following the concept that 10 Omote is executed with the Omote on the stone (i.e. stamps "up"), but I'm watching a YouTube video by a honer from another site (Google brought it up, I'm only a member here at B&B ) who executes it the other way around.

Once again, do I everything backwards?

 

[Gamma]

I think you'll find that most, not all, people hone more on the Omote.
There are a lot of theories out there. i kinda came up with my own.
Jim R had a decent blog post on them about 2 yr ago.

 

[rockviper]

Thanks, Gamma. I think I read this a year or so ago, but now I have daily brain farts and need a kick every now and then to perform a reset.
It seems like I am doing it "right."

 

[Gamma]

It gets confusing because new jacks keep showing up with new methods that they claim to be the new answer.
There's nothing wrong with new techniques - but when you're learning, it's hard to figure out what to do if everyone says something different. Mixing techniques can be a disaster. Better to have a solid ground game I think - then go for it.

 

[Bayamontate]

There's a lot of Omote assassination going on because of excessive pressure. I prefer to go one grit level lower over pressure. Ask anyone I've honed Kamisori for, they'll tell you their Omotes look beautiful.

 

[Gamma]

Omote assasination - term of the day!

 

[Steve56]

I think it's best to think about what's going on. I love Masahiro knives, which are sharpened 90/10 and I reset them a little better than that. I sharpen on the "beveled" side for most of the regime, then just 6 strokes or so on the "flat" side at a steeper angle, just enough to take off any wire edge and make the bevel more robust. Fantastic cutters.

Cheers, Steve