Thread: Jnat finishing

I like to start with a slurry made with a DMT - there is no issue that I'm aware of using a DMT to make a slurry on a JNat? I do normal x-strokes or rolling x-strokes depending on the blade. I dilute incrementally with my fingers dipped in water a few times until almost clear then rinse throughly and do some strokes on just water. Then I rinse again and squeegee as much of the water off the stone as possible with a finger and do ultra-light strokes until the stone is just barely wet (damp really) but not bone dry. At this stage there is very little resistance from the stone and I get very good results. Microscopy of the bevel looks like fine sparkly dust rather than scratches. I do have some JNats that leave more of a mixture of the dust pattern and scratches. I use basically the same approach with all of my JNats and get very consistent results. YMMV...

-john

Dmt slurry works fine although i think a nagura progression can lead to better results, well at least thats what i get. Havent used a dmt for slurry in a while. One thing that you can also do is use a harder stone as a tomo to raise base stone slurry only. You need to round a corner carefully to avoid scratching the stone. The slurry you get is finer than the dmt though IMO. Or raise the slurry and use another blade or knife to break it down before using the one your finishing. This will make the dia plate slurry finer before it hits the blade. Just food for thought. No expert here, just sharing some observations with my stones.

Originally Posted by bill3152

Dmt slurry works fine although i think a nagura progression can lead to better results, well at least thats what i get. Havent used a dmt for slurry in a while. One thing that you can also do is use a harder stone as a tomo to raise base stone slurry only. You need to round a corner carefully to avoid scratching the stone. The slurry you get is finer than the dmt though IMO. Or raise the slurry and use another blade or knife to break it down before using the one your finishing. This will make the dia plate slurry finer before it hits the blade. Just food for thought. No expert here, just sharing some observations with my stones.

It all depends on how you make the slurry - I work it for a while until it feels silky smooth then dilute it to the density that I want. I use my JNats for maintenance so I actually want a bit of cutting power in the beginning to refresh the edge a bit. Plus all of my JNats are very fine vintage pre WWII stones that were very hard to come by - one is so fine and dense that even with a DMT it takes some effort to make a decent slurry. I'm a firm believer in the fact that it's only the last abrasive that touches the edge that really matters because if you're honing correctly all traces of a previously used lower grit abrasive should be removed as you progress. So if you're going to finish on the natural stone with no slurry you're exposing the edge to the variably-sized particles embedded in the surface of the stone not a broken down finer slurry. I go from a Shapton 8k (because Shaptons are really fast) to a JNat or other natural finisher when I dip further down into a progression. But whatever gives you the best results is what really matters - there are many ways to skin the JNat cat....

john

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

Originally Posted by aa1192

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

It will probably stick to the stone very quickly . Suggest the coarse that eveyone uses.

Originally Posted by aa1192

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

I like this one - cheap, easy to grip and works very well....

Amazon.com: DMT W6EP 6-Inch Diamond Whetstone Sharpener - Extra-Fine With Plastic Box: Home Improvement

John

Many people are against using a coarse diamond stone on a fine J nat for slurry buildup because it will make the surface of the stone rougher and may gouge out larger particles that will be harder to break down. I have used a 1200 grit DMT stone as a slurry stone before and it worked well. I also have a DMT 8K plate around here I need to find!

I tried the 1k but it was too slow so I moved to the 325. The edge seems pretty good but I need more time to perfect it.

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.

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.