Diamonds are man best friends

nozh2002

nozh2002

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I did some sharpening on Medium Density Fiberboard - MDF sprayed by diamond powder and results are just amaizing with Buck110 BG42 (custom) I achived results I never have or even never seen before.

It is 40gramm on thread test:

30 ++++
40 ++++++X+
50 +++++
60 ++++

the best result I saw so far was Currahee and Military BG42, which was 60 - sharpness out of the box.

Here after 1200 EzeLap diamond benchstone (9 microns) and diamond powders on MDF 6 micron, 3 micron, 1 micron and 0.3 microns I have this amaizing result.

I hope I'll be able to repeate it next time.

I am doing some experiments with sharpening. I used diamond powder on leather, but it seems too soft and affects sharpness at this level - I was not able to get more then 70. Now on MDF which is cheap as dirt and widely awailable in big blocks on OSH or HomeDepot is works much better.

Today I will continue with 0.15 micron powder and hope I will be able at least not to make it worse.

I tryed it initially with Buck 110 420HC and results was less impressive - same 60 as Military and Currahee. I am not sure is it because on steel - 420HC is cheap entry level steel (which named as "easy to sharpen"), or my skills is gettiing better, I will continue my experiments and report results here.

Thanks, Vassili.

P.S. Just ried hanging-hair test from the other thread - it works. I tried several times. However it also works with Buck 110 420HC wich shows 60 result, not 40 as BG42.
 
Congrats on your "personal best"!
I assume you use a trailing stroke? Where did you buy the diamond powder?
 
It is not strokes - more like polishing, I try to make it stable, achivable for sure. This light strokes sometimes works sometimes does not (according to my testing) - I am looking for something which is not art or magic and can be done for sure.

Diamond powder is available in stores for jewelers. I got it in a spray form which is most convenient to apply.

Thanks, Vassili.
 
I meant in which direction are you moving the knife. Are you pushing with the edge first or with the edge trailing or do you move it in circles or do you move it along the edge....?
 
HoB said:
I meant in which direction are you moving the knife. Are you pushing with the edge first or with the edge trailing or do you move it in circles or do you move it along the edge....?
Click to expand...

Oh, sorry, yes I am moving it in opposite to the edge direction. First on diamond bench-stone it is in same direction - like cutting and on MDF is same as on leather with edge trailing. Otherwise it may just cut surface - MDF or leather.

I think leather is used because it hold abrasive particles in the pores, but it is bend under edge and so affect the final angle, MDF has similar surface to hold finest abrasive, but less soft and so affect edge angle much less. I guess it is possible to make same thing with leather with very slight strokes, but MDF makes it much easy so result are better with less effort and more stable.

Thanks, Vassili.

Here this MDF blocks I made:

sharpening-05.jpg
 
Interesting that BG-42 worked better than 420HC, it certainly would not be expected given the chemistry and optimal heat treatments for both.

-Ciff
 
Nozh2002,
I spoke to a colleague about this concept and while he was very positive about the diamond aspect of the project he just doesn't think that it is possible to get an optimal result with MDF--too soft. He suggests a soft steel instead. He custom hand engraves precious metals and said that he just couldn't imagine using anything as soft as MDF. I got the impression that he uses a lapping machine from USP but haven't gotten the details yet.

Has anyone tried these diamond lapping compounds or slurries on soft metal?, not mechanized?

Does anyone use the USP lapping machine?
 
As far as I know, yuzuha has played around with that for a little bit. Steel lapping plates are not uncommon. They are not that expensive, but you need one for each grid, because once the grit embeds you won't get it out, and it get a bit more expensive. Still fairly cheap in comparison to a waterstone.
http://www.hidatool.com/woodpage/stone/flatting.html

However I would think that MDF is a lot more forgiving.
 
I think that this is precisely his point, you don't want forgiving when you are doing precision sharpening and embedding is a good thing by his way of thinking. His tolerances may be completely different than with most of us, I wouldn't want to touch part of anything worth, 20-60K with a knife! unless I knew exactly what was going to happen.

He did say that he uses, probably( his probably), .5 micron diamond to strop; so there is room for flexiblility it appeared, just not when sharpening.

Seriously he looked at me like I had three heads and just about said I was in the dark ages without a precise machine ----and forget about something as relaxed as MDF, even if it is seductively inexpensive.

He also mentioned crocus paper to touch things up a bit, not sure exactly when in his sharpening process.

Any users or takers on crocus paper?

I'm going to have to watch him to see what this is all about.
 
Those kanaban need to be smoothed. They have grooves in them to help hold coarser SiC grit. Grind it down smooth and it would make a good iron strop. An alternative would be xerox paper or a big post-it note on a granite surface plate (paper is very thin so there wouldn't be much give).
 
yuzuha,
Would glass be a good alternative to granite or steel?
 
MDF is not my idea. I stole it from diamond sharpening set I saw in local WoodCraft store. It has diamonds 5 MDF plates and glass as an other option. I heart about sharpening on the oak from DmitryM before, but without details.

For me MDF is harder then leather I used before for polishing and it works better then leather.

I got that exceptional result and to me this is prove that it is possible.

However I have to admit that I was not able to reproduce it yet.

After I went from 0.3(50000mesh) to 0.15 (100000mesh) result was much worse:

50 ++
60 +++++++
70 +X++++
80 ++++
100 +
110 +

I try more delicate strokes and have improvement to 60 then to 50, but to my frustration then again back to 70. And resharpening it with 0.3 microns again turns it even to 80.

Now I went back to 400 and 1200 EzeLap to freshli resharpen, and found out that I increase angle too much so I have to spend some time reprofiling it a bit.

I use lightest sharpening wit 1200 and have same result as when I use it with some pressure:

80 +
90 +++
100 +++
110 +++X++
120 +++
130 +++
140 +
150
160 +

I want to investigate this completely and sharpens little by little with lightest possible strokes after ten strokes I measure sharpness:

70 ++
80
90 +++++
100 +++
110 X++++
120 ++++
130 ++

Some improvement I can see - median moves to the boder between 100 and 110. Next 10 lightest strokes shows:

80 ++
90 ++++++++
100 X++++
110 +
120 ++++
130 +

I consider this as noticible improvement. So after only 20 lighest possible strokes. And I guess this mean I should not apply any pressure - diamonds just works this way. And pressure was cause of the problem I guess. Next ten shows:

50 +
60 +
70 ++
80 ++++++
90 X+++++
100 +
110 ++
120 ++

Another step forward. And each time it is only ten strokes. It is kind of time consuming exersise, so I will continue this evening. I hope that at some point it will start showing no improvement and I turn to next grip etc. I hope that I finally learn how can I for sure achive what I got initially by accident.

Thanks, Vassili.
 
annr said:
yuzuha,
Would glass be a good alternative to granite or steel?
Click to expand...

The rule for laps is that the diamonds (or any abrasive grains) embed themselves in the softer material and abrade the harder material. So, if you steel is harder than glass, go for it! Though glass is terribly brittle and non-malleable so wouldn't make the best lap anyway. Copper would be good, except that it could be a health hazard. Lapidary work is often done on tin laps. Soft, high-graphite cast iron is often used for lapping plates/tables in tool and die shops. You could probably get away with a hunk of soft sheet metal or aluminum slab or strip of wrought iron if you could make it flat. Masonite would work, so would sheets of acetate film on a surface plate. I just mentioned paper because it is too thin to have much give, yet has enough porosity that it would be easier to spread diamond pastes on it, while smoother surfaces would probably work better with sprays to get an even distribution... MDF works fine with coarser grits and is pretty easy to spread a gob of diamond paste on, though I'd think it is a bit too rough and uneven for sub-micron grits.
 
In same jewelry shop they show me high density fiberboard circle, but surface was not too flat. How is it possible to make flat surface? I can use hardwood - ebony or something, but how to make sure that surface is not too rough?

What about plastic glass - plex?

Thanks, Vassili.
 
Yes, I was just thinking about that. Plexi or lexan might be a good idea. It won't be as flat as a steel lapping plate, but its not bad. I will try that, we have a lot in the lab. Also, leevalley sells a glass lapping plate and some plastic adhesive sheets that you glue on the glass, which helps protect the glass and allows the abrasive to embed. That might work as well.
 
Thin plexiglass should work but you'd need to put it on something to make it stiffer. Same with masonite.
 
I was thinking more of a good sized chunk 3/8 to 1/2" thickness. In 8x3" that will have practically (3/8") or no (1/2") give. If you want to step it up another notch you can use lexan where you really wouldn't see any flexibility anymore even if you were determined to bear as hard as possible down on it.
 
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