DMT D8C 8x3

[cityjim]

Finally decided to pick one up . Had to see what all the hype was about .

Out of the box I felt the synthetic diamonds or diamels as I call them . Wasn't as coarse as I thought it would be . This thing is called coarse but is more of a medium IMO .

Did about 20 light passes under water to true up my soft Arkansas stone . Only used the weight of the heavy DMT block . Afterwards cleaned the abrasive surface with dish soap then Comet clenser per the DMT instructions . Felt the abrasive surface . Noticed it went from a so called coarse to a fine in one minute .

How the heck does an Arkansas "soft" wear out a DMT diamel stone so fast ? I thought the DMT might be clogged or something . Took pure acetone , liquid freon which obviously you can't buy anymore , MKT , kerosene and finally wd-40 . Should've been perfectly clean . Used the liquid freon as the final cleaner as it leaves zero residue . I was like *** .

Then I rethought what I stated at first . DMT uses synthetic diamonds . Which are not true diamonds at all and not even close to being as hard .

I must give it up though for this one point . The D8C was very flat . They get an A+ for that . But ultimately let down as the abrasive surface just doesn't last . Sure you can send it back in . But what kind of product openly states sending them in like they do on their web site ? Must have a lot of returns .

I looked on the DMT web site for any stated warranty . All I read was a lot of vague adjectives . Nothing like lifetime or one year anything . I see why now ........

Back to the tried and true Arkansas line .

cityjim

 

[Seraphim]

OK, so it no longer felt "coarse" to your hand, but how well did it lap your hone?

I have a DMT 1200, that is well worn. It still cuts fast, but now leaves a finer finish.

 

[Chimensch]

I think I read that the DMT needs to broken in first. Like with a chisel or something ... or am I wrong?

 

[treydampier]

I am with Seraphim on this. MIne feels used and it was I believe a 325 grit stone. I actually like the way it laps my Nani's especially the 5,8,and 12K because it does leave a smoother finish. I say keep it a while and if it stops lapping your hones, then send it back.

 

[Slartibartfast]

Yup. I usually just rub an old nasty razor across it a few hundred times(does not take that much time).

I think I read that the DMT needs to broken in first. Like with a chisel or something ... or am I wrong?

 

[jkh]

Bummer it didn't work out for you.

 

[Shaman]

Back to the tried and true Arkansas line

I just bought a set of arkansas benchstones from Halls (wonderful folks to deal with BTW). Got the 8x2x1 soft, hard, and surgical blacks. So far I've only used the soft and have managed to restore the bevel but have not quite got it to the point that it will shave arm hair. At what point are you moving up from soft to hard to finish? Sorry if it looks like I'm trying to hijack the thread, I'm not. Just had that one question and novaculite users seem to be hard to find here.

 

[holli4pirating]

I don't know about with Arkies, but I don't move off my Norton 1k until I can shave arm hair. IMO, if you cannot shave arm hair, the bevel is not set.

 

[Sticky]

The red 4 1/3" 600 DMT in my current avatar has been used almost daily for over 22 years. The first 12 years was heavy use. It still works fine. They tend to "wear-in" quickly and then cut well for years; barring defects or too much pressure, undercutting, etc.

If your 325 isn't still cutting, I'd send it back.

 

[cityjim]

OK, so it no longer felt "coarse" to your hand, but how well did it lap your hone?

I have a DMT 1200, that is well worn. It still cuts fast, but now leaves a finer finish.

Like butta . Did a really nice job . Again an A+ for being super flat . Just felt like it wore down too much .

Later I took off the last 1% of imperfections (machining marks) on my Spyderco UF ceramic . Now the DMT feels really smooth in a bad way . Seems to be cutting slower now also .

I was told to buy the extra coarse for lapping stones . Didn't want to leave a rough finish on them so I picked the coarse . Was a DMT noob and might of made a poor grade choice ??

I see several guys say keep using it . Guess I will till it turns glass smooth then send it back . One more trip on the Spyderco ceramic though and I think this would be there .


cityjim

 

[cityjim]

I just bought a set of arkansas benchstones from Halls (wonderful folks to deal with BTW). Got the 8x2x1 soft, hard, and surgical blacks. So far I've only used the soft and have managed to restore the bevel but have not quite got it to the point that it will shave arm hair. At what point are you moving up from soft to hard to finish? Sorry if it looks like I'm trying to hijack the thread, I'm not. Just had that one question and novaculite users seem to be hard to find here.

Exactly as holli4pirating states .

Use the Arkansas soft (medium grit) till the bevel is cut . Do not leave the Ark soft till it shaves arm hair rather easily . You will feel it bite into the hairs and will cut them cleanly . This bite as I call it needs to be rather impressive on initial hair contact . Only then you progress to the Ark white (hard) then Ark black (hard) . If it does not shave arm hair and you progress , you will be wasting your time and the edge will be mediocre . If you get here you did not do your part .

What I do is when you progress to the next finer stone , your first initial strokes will "feel" a little rough . Then will smooth out say 3-6'ish strokes into it . My opinion is there is no set amount of strokes to hone by . I go by feel . When the blade starts to glide smoothly over the stone , progress up in grit number . And check along the way that you still have an impressive bite into some arm hair . This bite will tell you the edge is sharp . If the hairs don't pop away from the blade then again you are not ready to move up . Several times I get a good nasty bite and do the old American more is better thing . Hone a couple more strokes and the hair bite is lost . Went into over hone mode . Have to back up a bit till my bite returns .

I hear a lot about guys doing 60 strokes then 100 on that stone or strop . That never worked for me . I feel the blade and listen to what the stone is doing to the edge . It either cuts hair or it doesn't . Good luck .


cityjim

 

[cityjim]

i don't know about with arkies, but i don't move off my norton 1k until i can shave arm hair. Imo, if you cannot shave arm hair, the bevel is not set.

+1

 

[kwigibocity]

Don't worry about the appearance of the layer, it takes a lot longer than you think to wear away. I used to lap with a d8c VERY heavily, exclusively for hard stones and hard man-made ceramics, and though that surface eventually looked like nothing was there it still continued to frost glass again and again when I'd test it. Eventually I got about a decade of near-daily use out of that one plate.

They're vague w/ their warranty because they want to exceed any practical expectations. I'm sure if you wanted you can send it back to them with a note of your concerns and they'll send you a new one.

I do hear ya, though; I'd rather buy a product with practically no concern for failure than one with a warranty tripping over themselves to make me happy.

 

[Utopian]

Keep in mind that DMT only recommends the D8C for lapping waterstones. For lapping any other hones, they only recommend the D8XX. If a coarser grit hone is lapped with a D8C or finer diamond plate, the nickel substrate can be undercut and lead to the release of the diamonds.

However, if you only did something like 20 laps with light pressure under water, I cannot imagine that to be sufficient to damage your plate. Honestly, I have no idea what is the problem with your plate. I will say that the breaking in of the plate is not the issue. That is only to remove/wear down a few aberrant higher diamonds that will lead to stray scratches in your hone.

I would suggest that you call DMT to sort it out with them. I have no personal experience in dealing with them but I have read others' accounts of them being very cooperative.

 

[danjared]

I've done the same sort of thing with my D8C without problems. (Actually, I've used it on a Spyderco UF and medium, a translucent Arkansas, and several waterstones.) It's really worn in now. However, even my D8XX feels slow on the Spyderco UF, and I did a progression on the Spydies and Arkansas lappings, i.e. from the D8XX to D8X before using the D8C. I recommend testing the D8C on a waterstone or steel. Is it slow on steel? If so, then definitely send it to DMT.

 

[ferroburak]

Yup. I usually just rub an old nasty razor across it a few hundred times(does not take that much time).

What's the logic behind this?

 

[SliceOfLife]

...synthetic diamonds . Which are not true diamonds at all and not even close to being as hard .

wat? You may want to do some research. Synthetic diamonds made for abrasive use (at least excluding very cheap manufacturers) are harder than natural diamonds.

edit: Oh threadomancy.


The logic is I believe that there may be diamonds that aren't fully adhered, and the break in lets you remove them. DMT plates made recently come with little note cards alerting you that they do a break in at the factory now.

 

[LessLemming]

I don´t really get what this is all about. I mean, come on. Almost any thread concerning DMTs for lapping says:
let them brake in, they will lose agressiveness quickly when used for lapping (what they are NOT designed for), but will do the job for a long time,
and never, ever use the DMT C on Arkansas, Spyderco or Barber Hones.

If you want to lap these delicate stones use a flat granite plate with loose abrasive like SiC

 

[Will P.C.]

I don´t really get what this is all about. I mean, come on. Almost any thread concerning DMTs for lapping says:
let them brake in, they will lose agressiveness quickly when used for lapping (what they are NOT designed for), but will do the job for a long time,
and never, ever use the DMT C on Arkansas, Spyderco or Barber Hones.

If you want to lap these delicate stones use a flat granite plate with loose abrasive like SiC

You can use them for lapping right out of the box