Thread: Jnat finishing

Originally Posted by onimaru55

A well worn DMT will leave a Jnat like glass. An Atoma 1200 not quite that smooth. Have used both for years. Never seen a chipped or dented edge.

One thing to watch out for, wait for it, is pressure. Both with Nagura & diamond plates. Many of the problems people may experience can be alleviated with lighter pressure.

At the other extreme Nagura can release sandy or gritty particles also, which will damage an edge. Here a quality Nagura may be in order but again pressure can fracture large pieces off & cause problems.

This whole debate can be likened to the fishing fraternity where some believe high tide will result in more catches & some believe low tide is best.
The skill of the individual in a particular scenario plays a bigger role.

+100%

Add in the fact that the stones themselves complicate the results because they are variable and you get our wonderful SRP saying of YMMV

Too many variables to call it other then on an individual basis..

To close, My very well worn DMT 325 which I have proved at the meets to leave a near glass finish on hones works absolute wonders when I use it on my Nakayama then work the slurry until near dry and finish with super light laps to take only the fin to a mirror like finish leaving a beautiful haze on the rest of the bevel

I would just keep messing with it until you find what works best for you and your techniques..

+++1 too

If you work the slurry long enough with an "extra fine" DMT - what ever that is... You get a very fine and smooth slurry - and I also have never seen any scratches on my JNats nor do I get even nanochips in the finished edge.

John

I always use slurry on my asagi (mined ca. 1880 according to Alex) & get my best edges doing this, working the slurry until almost dry. I never dilute (found no benefit) & find the edges on water not as nice. For slurry, I use my well worn DMT 325 & find this gives the best, most consistent results. I do have a matched tomo as well but rarely use it.

+1 on watching pressure. I did an experiment using pressure followed by no pressure on both the tomo & DMT. In both cases when pressure was applied, the edge was no good. When no pressure was used, the edges were excellent. In fact, I liked the edge off the DMT slurry the best.

Originally Posted by aa1192

I may try the dmt slurry. Hopefully a 1k dmt card won't be too rough

Just saw this. When I got my 1st Jnat I picked up one in 325. Found that the edge of the card scratched the stone something fierce & have been using the regular 8x3 plate ever since. No issues there & the stone is like a mirror when dry if rinsed off.

Be careful of a DMT1K stone on a Japanese stone. The stones are porous enough that they absorb a bit of water. If you're rubbing up a slurry, you just might get it stuck really bad to the plate, and unlodging it carries the risk of actually breaking the stone.

I see that Im vastly outnumbered here with the slurry vs nagura methods. Well I will not argue that a diamond plate isnt capable of putting a great edge on. BUT the AHA! edges Ive gotten were off a full nagura setup, including yae, chu, tbn and koma. This system is an old one and I think that it makes the most sense. Just food for thought for anyone looking to see what they can get. I think if you have the time and apply yourself with it, you may be surprised at what they can do for you.

Originally Posted by Bruno

Be careful of a DMT1K stone on a Japanese stone. The stones are porous enough that they absorb a bit of water. If you're rubbing up a slurry, you just might get it stuck really bad to the plate, and unlodging it carries the risk of actually breaking the stone.

The first day I had it I got my tomo stuck. It was an insane amount of suction and I was lucky to get it off! I grooved the tomo after that and keep any eye out for any suction building.

Yeah, the Atoma 1200 works fine because of the pimpled surface, but I wouldn't even think of using a DMT 1200 on a hard natural. The one time I tried years ago, it scratched the stone & also pulled a lot of zinc off the plate. Never again.

Originally Posted by PA23-250

Yeah, the Atoma 1200 works fine because of the pimpled surface, but I wouldn't even think of using a DMT 1200 on a hard natural. The one time I tried years ago, it scratched the stone & also pulled a lot of zinc off the plate. Never again.

There was a thread about this in the past & DMT themselves say nothing finer than the 325 for lapping.
Of course slurry generating may be less of an issue.

Originally Posted by bill3152

I see that Im vastly outnumbered here with the slurry vs nagura methods. Well I will not argue that a diamond plate isnt capable of putting a great edge on. BUT the AHA! edges Ive gotten were off a full nagura setup, including yae, chu, tbn and koma. This system is an old one and I think that it makes the most sense. Just food for thought for anyone looking to see what they can get. I think if you have the time and apply yourself with it, you may be surprised at what they can do for you.

Scientifically speaking, it's still really only the last abrasive that shapes the edge that matters - everything preceding it is erased by the finishing process if done correctly. While I appreciate the "romance" of using your setup, going from a synthetic 8K (for example) to a high quality JNat will essentially leave the same exact edge as your progression if the final abrasive is identical. I've been studying edges with microscopy since I started honing and the final bevel scratch patterns obviously vary widely from abrasive to abrasive - JNats being the most fascinating IMO. Some of mine don't leave a scratch pattern at all - just sparkly metal - how this is I don't know - that's the limit of light microscopy. JNats are the most unique hones out there and I'm happy they exist!

Just my $0.02

-john