Thread: Brand new DMT 325 vs Brand New Naniwa 12k. Not a good combination?

For my 12k, i just flip the dmt over and wet-stick my 600 grit sand paper to it. Works great for me. Or you can do the same with the norton lapping stone.

USUALLY the plate itself is fairly flat. Onimaru is suggesting that it is not. Use a straight edge by holding it against the plate and looking for a gap when looking toward a light. If it is not flat, I'd send it back.

IF the plate is flat, then the breaking in is the issue. The diamonds are coated onto the flat surface but the highest point for some of them can be higher than the majority of them. These cause the apparent scratching until they are worn down to the level of most of the other diamonds. Rubbing steel on the plate speeds this up.

Given that no harm was done to your Nortons, I have no clue but here is a speculation:

When you lap, it is a good idea to occasionally rotate the stone or the hone (not both!) 180 degrees during the lapping. I'm assuming that you did not do this. If you repeat the lapping and rotate the hone, then if the other end of the hone is scratched, then I would assume the plate is at fault. If the other end is not scratched, then the hone may have a high end that looks worse because the plate was not broken in.

Originally Posted by Xyphota

Im not sure id be willing to 'tap' my DMT as to make it straighter. Firstly, if it is out, there will be no way to accurately guage if i get it perfectly straight, completely defeating the purpose of having the stone IMO :P, and with the plate being as thick as it is, I know I would need to hit it pretty hard. Should I email DMT about it? (assuming its not a break in issue).

Sorry , did not make it clear. You possibly have a small high spot of diamonds near the end of the plate. If you can locate it & give it a tap you will break the dianmonds off as they will fracture. I use the corner of a spyderco ceramic hone to rub uspecific areas. Makes short work of it & can be used to break in the whole plate but in small doses only. The diamonds are quickly levelled.
If the plate itself has a high edge it needs to be returned for replacement.

If one of the corners is raised a few taps will do it,
they do however have solid customer service, if you call they will direct you.
that does look like more than a few high stones unless they all were bunched up in one spot?
which I guess could happen.....

Originally Posted by pfries

If one of the corners is raised a few taps will do it,
they do however have solid customer service, if you call they will direct you.
that does look like more than a few high stones unless they all were bunched up in one spot?
which I guess could happen.....

Yes that can happen. A 2mm high spot will create such damage.

Originally Posted by onimaru55

Yes that can happen. A 2mm high spot will create such damage.

I have not seen that personally yet, but it is great to know. Sometimes we approach thins like a rocket surgeon and miss the obvious.
Thanks OZ

Happened to me with a 400 grit Atoma.
Take a pencil & try to draw small figure 8's on paper & also rub it back & forward the same distance as when you lap. See the size of the pattern ?

Originally Posted by pfries

If one of the corners is raised a few taps will do it,
they do however have solid customer service, if you call they will direct you.
that does look like more than a few high stones unless they all were bunched up in one spot?
which I guess could happen.....

+1 on this...
A clump of diamonds or a list of other problems could be the root cause.

I would note that if you are lapping a hone and you only see the problem
in one corner you are not lapping with figure 8s and not rotating the
lap over the hone.

Also note that you want to lap a minimum amount of water stone
away. Think one or two sheets of paper.

The occasional trenches you see do have value. I use them to keep
track of when I have used enough hone to need to lap it again. When
they are gone it is time to lap the hone again.

Also use a lot of running water as water stones are soft enough
that you can collect a layer that keeps the lap from giving the
entire water stone surface attention. One of the things I have seen
is scratches on corners with a smooth central region. i.e. I have
seen what you see and it was thick slurry mud getting in the way.

Always contact customer service ... your picture is all the evidence most
folk will need to understand.

What a dissapointment. Its things like this that drive me nuts. Your feeling good about your new gear and then this happens. Sorry man. I'd try to steel scrub the offending corner once more and see what happens. Then tap the high diamond area as onimaru55 recommends. If it failed, I'd call and ask for a replacement TODAY or I wouldn't be able to sleep. This makes me feel lucky my plate was in good order when I got it. Things like this happen to me when theres a 7 day weekend and the vendor is closed for a month.

Lapping is done faster, cheaper and better using wet/dry. I have the atomas and dmts also. The finished product is better as you have lots of choices for grits. I know you can get grit on your stones, but you can get diamonds on them from the diamond plates as well.