Thread: Jnat finishing

Originally Posted by bill3152

Just so you know, 325 grit is something like 45 microns. An 8k hone particles is about 3 microns. I have no idea what size particles will flake off the stone with the dmt, but imo you set the edge back quite a bit doing it this way. The bigger particles can scratch the bevel and maybe even dent or chip it. Not saying not to do it but there are other ways that are less destructive imo. Nagura and tomo nagura slurries are much finer. And the more you set the edge back , the more work you have to do to get back to pre dmt slurry.

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.

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

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.

I will say the slurry from my Tomo and dmt are vastly different. My Tomo slurry seems to be all Tomo while dmt slurry is all base stone. Which is better? I haven't figured that out yet.

Only you can know for sure, though experimentation--there are a lot of factors that come into play. On my stone (which is a fast cutter for a finisher), I find using a diamond plate offers more control & less chance of overcooking the edge, while my tomo is actually even faster cutting but is easy to overdo it.

If I had to guess, I would say there is probably more variation in particle size when using the DMT, along w/ a controlled, slow release of fresh particles into the mix, which limits how small the average mix can get, whereas the tomo does not. That being said, finishing on DMT slurry is noticeably sharper & smoother than crox. Tomo slurry on mine is often too much of a good thing.

Here's some empirical, non scientific, maybe even pleonastic statements.

I shave off an Atoma 1200 diamond plate slurry on my Nakayama Asagi.
I can also shave off the same stone & a fine Tomo slurry but I won't shave off any Nagura stage.
So I say all Nagura, except a Tomo are coarser than a diamond plate slurry & how you get to end game does'nt much matter.

Originally Posted by onimaru55

Here's some empirical, non scientific, maybe even pleonastic statements.

I shave off an Atoma 1200 diamond plate slurry on my Nakayama Asagi.
I can also shave off the same stone & a fine Tomo slurry but I won't shave off any Nagura stage.
So I say all Nagura, except a Tomo are coarser than a diamond plate slurry & how you get to end game does'nt much matter.

Why have hones then, why not get all dmts to 8k and then use 1 dia slurry or tomo?