Flattening stone for Nubitama Bamboo 150?

D

Danketch

Joined
Apr 27, 2007
Messages
583
Hello all,

Currently I use a DMT XXC for flattening my Naniwa Choseras (400 is lowest). I'm contemplating getting a Nubitama Bamboo 150, and wondering if my DMT will be enough.

I think it should, as a 120 grit, but would the Atoms 140 still do the job, and or last longer/be better or is there some other more better alternative?

Thanks
 
Danketch said:
Hello all,

Currently I use a DMT XXC for flattening my Naniwa Choseras (400 is lowest). I'm contemplating getting a Nubitama Bamboo 150, and wondering if my DMT will be enough.

I think it should, as a 120 grit, but would the Atoms 140 still do the job, and or last longer/be better or is there some other more better alternative?

Thanks
Click to expand...

Hi,
just curious,
why not flatten on a cinder block or concrete block?
or maybe one of those silicon carbide flattening stones like a tile rubbing stone/concrete rubbing brick?
 
The Nubatama Bamboo 150 is a rather tough stone with a very hard abrasive, you would turn a cinder block into a pile of mud trying to lap one. Also, you just don't flatten waterstones on concrete, that's a big no-no.

The DMT can work but you will likely damage the plate because the waterstone is so coarse and aggressive. Once the mud starts forming on the diamond plate it's able to grind deep into the plate attacking the nickle plating holding the diamonds. This leads to excessive plate wear and is not much better for the waterstone. When you use a diamond plate the diamond abrasive is so hard that it is cutting the grit on the waterstone. This is not really an issue at finer grits but at very coarse levels you basically smooth and glaze the surface of something like the Nubatama 150 when lapping with a diamond plate of similar grit.

For this reason I've found that using other very coarse stones or Silicon Carbide powder in the 60-80 grit range to provide much better surface texture. This surface texture is much more important than you may realize and can change the stones performance dramatically.
 
Okay, that makes sense. I kinda thought 2 similar grit ranges would have a weird effect on stone. At least SiC powder should be cheaper than another diamond plate.
 
I initially lapped my Nubatama 150 with a tile rubbing stone. This stone was much smaller than the Nubatama, and due to my lack of skill and experience, I made the Nubatama much LESS level than it started! I lowered the end on one side quite noticeably. I was embarrassed by my terrible job.

Ken Schwartz advised me to use my DMT XXC to flatten it and to do it a little at a time. I was careful and did it a bit at a time with some running water near by. When the plate would stick to the stone, I'd carefully slide it off (not twist or "pop" it off) and rinse stone and plate. I was able to make the stone much flatter this way. I have no doubt that doing this aggressively or often would lessen the life of the DMT plate significantly. I've only done it a couple of times.

As Jason reports, this *did* smooth out the surface of the stone. Using it to sharpen seems to have refreshed the surface to closer to it's original state, but I'm really not sure. Plus I haven't touched that stone in over a year, so my memory isn't very sharp on this point.

I certainly wish I had something like loose grit and a glass or other VERY flat lapping plate instead.

Brian.
 
Jason B. said:
The Nubatama Bamboo 150 is a rather tough stone with a very hard abrasive, you would turn a cinder block into a pile of mud trying to lap one. Also, you just don't flatten waterstones on concrete, that's a big no-no.

The DMT can work but you will likely damage the plate because the waterstone is so coarse and aggressive. Once the mud starts forming on the diamond plate it's able to grind deep into the plate attacking the nickle plating holding the diamonds. This leads to excessive plate wear and is not much better for the waterstone. When you use a diamond plate the diamond abrasive is so hard that it is cutting the grit on the waterstone. This is not really an issue at finer grits but at very coarse levels you basically smooth and glaze the surface of something like the Nubatama 150 when lapping with a diamond plate of similar grit.

For this reason I've found that using other very coarse stones or Silicon Carbide powder in the 60-80 grit range to provide much better surface texture. This surface texture is much more important than you may realize and can change the stones performance dramatically.
Click to expand...

I'm asking out of ignorance, why is it a big no no to use the sidewalk?
 
For a hard India stone or Arkansas it's ok but for a waterstone you can contaminate the surface and generally it's just way too rough and wearing on the waterstone. They are a high quality tool and should be treated as such, IMO.
 
Jason B. said:
For a hard India stone or Arkansas it's ok but for a waterstone you can contaminate the surface and generally it's just way too rough and wearing on the waterstone.
Click to expand...
Hi,
What kind of contamination?

If concrete block is too rough you can always prepare it :D
But its hard to imagine it being too rough, its about the same smoothness as flattening stones.
 
bucketstove said:
Hi,
What kind of contamination?

If concrete block is too rough you can always prepare it :D
But its hard to imagine it being too rough, its about the same smoothness as flattening stones.
Click to expand...

The stone will pick up bits on concrete.

Use whatever you wish but it is not recommended to use the sidewalk or concrete blocks.
 
Jason B. said:
The stone will pick up bits on concrete.

Use whatever you wish but it is not recommended to use the sidewalk or concrete blocks.
Click to expand...

Hmm, bits of concrete, how many bits? 1 bits per inch? 10 bits per stone?

Speaking of recommendations :) Tojiro says or you can even flatten it by rubbing it on something hard, e.g. wall or pavement.
 
The Atoma 140 works fine to flatten the Nubatama 150. No need improvise.
 
Okay, so I just got the Bamboo 150. Haven't used it yet. Reading diff reviews, I see some give a 5 min soak, and others do a permanent soak. What is best for this?

I am going with the 60-80 SiC powder for lapping, on granite or glass.

Thanks again for all the help.
 
I usually soak that stone until water comes back up through the top of the stone when you remove it from your soaking container. 30 minutes I expect. No need for a permanent soak. Its pretty porous. That stone needs to be lapped a bit before use to get through the chalky top portion of the stone when new. The Atoma is still your best bet.
 
I usually run mine under the tap for about 1 minute then go to work.
 
Jason B. said:
The stone will pick up bits on concrete.

Use whatever you wish but it is not recommended to use the sidewalk or concrete blocks.
Click to expand...

I flattened a coarse stone on side walk before . 3 things happened and probably what Jason was referring to . First I got deep scratches in my stone it was flat but the surface was not smooth edge got caught in the scratches I had to lap the stone after concrete .

Second thing was pieces of concrete/dirt//grit whatever embedded in the face of my stone .

As far as a new stone and soak times here's what I do . I sharpen close to a tap I'll take my stone and my little gun thing in the sink and turn it on . Let water flow and watch it absorb when it slows down I keep the gun on the smallest setting on to keep the stone wet but not wash away all the slurry . Works great if you have stones that need a long soak and nowhere to soak them , try a cutting board in you kitchen sink for a sharpening bench .
 
Spartan00 said:
I flattened a coarse stone on side walk before . 3 things happened and probably what Jason was referring to . First I got deep scratches in my stone it was flat but the surface was not smooth edge got caught in the scratches I had to lap the stone after concrete .

Second thing was pieces of concrete/dirt//grit whatever embedded in the face of my stone .
Click to expand...
Hi, what kind of sharpening stone did you flatten,
and how many pieces of concrete/dirt/grit whatever
were embedded in the face of your stone?

:) yeah, I've seen that kinda,
actual sidewalk can be really rough,
I used a reddish pink concrete brick , a paver from my backyard,
it was rough, and covered in dirt (i use the dirt side),
I lapped it for a minute with lots of water and another paver,
this cleaned the dirt, and released lots of pink dust/mud
the paver smoothed out and got lighter/whiter in color
then I flattened a dollar tree stone on it,
just kept flushing with water
and there was less and less "pink" in the mud until there was none,
just grey/blue aluminum oxide dust from the stone
next three times I flattened stones, no pink returned
yes, initially, some of the pink mud stuck to the grey/blue stone , in the hollow section, but it didn't last long
 
Thanks for the soaking advice guys. Definitely not gonna use concrete to flatten an almost $80 stone, but best of luck to those who do.
 
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