Not your every day mirror edge

Are you sawing into the wood with or against the grain? Just curious, wonder if it would make a difference.

Think cork would work?
 
Give it a shot, just try the black compound, see result in 1 or 2 minutes. With a few practices with the black compound, you should able to get a sticky edge.
Chris "Anagarika";12950492 said:
I haven't tried this yet, but if it works then it's the simplest sharpening jig ever made!
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Ok, keep in mind that I only have about 5 days worth of experience with this approach...

For shallow bevel I saw against grain. Deep bevel (3mm or more like scandi), I saw with grain. Against grain create a bit more banding. With grain produce smoother bevel face but sticking abrasives has greater tendency to fall toward the bottom, sometime can lead to dulling. If I was going to use SiC powder, either use it with vasoline/lard/wax or start sawing upside down. ;) heheh remember I said this for outdoor scenario using sand/mud/etc.. lowering the chance of too much abrasive fall toward the bottom.

Start saw with low pressure and not too fast, if you hear overly coarse sound for the current grit size, stop and make another groove. And don't over packed abrasive into the groove. Even at 250grit (black compound), it starts out coarse but quickly feel smooth. When learning, just check your edge more often.

A good way to load abrasive is by putting 1 or 2 dab of abrasive on each side of the knife bevel. Make light pressure sawing motion as the blade enter the groove, hence smear abrasive onto the groove walls. btw - don't use Ryobi black & white or compound that super sticky, just pita to clean between grit. Mineral oil help somewhat but I rather use SiC or Alumina or Diamond powder mix with vasoline.

Wine cork will works but probably slow due to softness. Basically, you want some material will give push back when wedge/groove, enough pressure to effectively abrade steel, while not easily close up on the apex (thus pushing any abrasive upward toward apex to dull it).
KennyB said:
Are you sawing into the wood with or against the grain? Just curious, wonder if it would make a difference.

Think cork would work?
Click to expand...
 
I tried it, but I'm not getting results like yours. I'll try to upload pics but the new photobucket app blows.

I'm using a pre-existing notch (to keep from bottoming out) and green compound.
 
Strigamort said:
I tried it, but I'm not getting results like yours. I'll try to upload pics but the new photobucket app blows.

I'm using a pre-existing notch (to keep from bottoming out) and green compound.
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Use the edge to create a new notch. You want a tight/snug fit. Bottom out is not a bad thing, since the apex is rubbing against plain wood, thus not dulling.

edit: hm... I didn't tried green/CrO compound yet. I wonder how it fares. I probably put a drop on paper, smear bevel green, then saw in the notch created before hand.

2nd edit:

I tried CrO/green on 1/4" thick pine for the same knife a few posts back. Earlier tonight, I whittle hardwood with this knife (finish sharpened on a diafold EE/3um). Anyway the edge wasn't pretty when I started this attempt using this pinch mirror sharpener. After 10 minutes of mostly doing pulls (too hard to push when I hold the wood with the other hand), I can push cut newsprint using part of the edge that don't have deformations from whittled hardwood. Again as I mentioned before (a few times), there are multiple ways to nurse/protect the apex, while abrade both bevel faces at the same time.

If I have time & ambition this weekend, I will make a video taking an edge from 320 stone grit to mirror + slice newsprint (push cut would be a bonus - hahaha to me).
 
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These shots aren't very revealing, but I'll post them anyway since I bothered to take them. :D

This is the notch I used.

IMAG1958_zpsji8cbvhy.jpg


Seemed like the notch was good. The edge didn't fit, so it had to be forced which seemed like the same as cutting a new notch.

The part of the edge is used in the notch.

IMAG1959_zps5pxetwfd.jpg


And part of the edge as it was before I tried the notch.

IMAG1961_zps8hqonvc6.jpg


It was fairly polished before trying. Again, the pics don't really show much, but it was less polished after.
I think it was the compound, or my technique. The apex was fine. Steel is 1075.
 
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Chris "Anagarika";12952752 said:
I think it might be good refine coarse bevel, not to redo a mirror bevel. Will update when I chance to test.
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That could be it too. The bevel had vertical scratches (spine to edge) so I figured it would come out more polished since, usually, a scratch pattern in opposite directions is better than one in terms of getting a finer finish. The burnishing from the compound may not match the scratch from the belt grinder though. Or, it's possible that I didn't use the technique long enough to attain good results.
 
Strigamort said:
That could be it too. The bevel had vertical scratches (spine to edge) so I figured it would come out more polished since, usually, a scratch pattern in opposite directions is better than one in terms of getting a finer finish. The burnishing from the compound may not match the scratch from the belt grinder though. Or, it's possible that I didn't use the technique long enough to attain good results.
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Might also have something to do with grain direction in the wood.
BTW, nice work Bluntcut, this could be used a lot of ways, even if it mightn't refine an edge to a specific target quality. Could pretty up the face of a blade very quickly for those of us that don't have a belt grinder (or that cut up all our belts doing hand sharpening).
 
@chris - it should works for coarse & touchup mirror bevels, just use appropriate size abrasive to get right scratch depth.

@Strigamort - try a fresh notch and perhaps against wood grain too. I used 0.5um HandAmerican CrO but other green should work to the level of its largest particle size. Scratches from this pinch mirror sharpener should be parallel to the edge. If banding occurs, try violin strokes - a little up & down while sawing. More pressure = faster result.

edit: cross post with Martin/HH :)
Use with grain abrasive works less aggressive since lots of abrasive fall/push between grain.
Use against grain, abrasive works more aggressive because abrasives mostly embedded at grain ends.
 
Strigamort, is that particle board you are using? That could definitely be an issue with all the voids and crap in that stuff.
 
Tried this on a inexpensive Kershaw last night. It was a coated blade, worked it with black on the end on a balsa strop for a few minutes and removed the coating totally and certainly didn't dull it. Gonna try it with some pine later today and use diamond paste and see where this goes for me. Once again Blunt goes way outside the box for a workable method. Makes me wonder......... What's next???? Good stuff! Russ
 
A 13 minutes video showed a knife sharpened at 1K, then used the Groove Mirror Sharpener with white(12um) & green (CrO 0.5um) compounds to create a mirror bevel and a burr/wire free newsprint slicing edge.

Thanks for watching & comments.
[video=youtube_share;cosuzhq28-g]http://youtu.be/cosuzhq28-g [/video]

52100 mini petty knife
IMG_0875.jpg

Reflection is not super mirror but not bad after spent a few minutes using the groove sharpener and just 2 grits progression.
IMG_0870.JPG
 
Wow. Nice work. What kind of a magnifier do you have to get that kind of edge detail in a picture?
 
Fascinating. If I hadn't seen it with my own eyes, I never would have believed it.

Thanks very much for all your work and experimentation!
 
Thanks, I used *GSI High-Definition Scientific Digital LED Microscope*. My next microscope would be one with higher optical magnification than this 100x (400x via digital zoom).

ShepardCC said:
Wow. Nice work. What kind of a magnifier do you have to get that kind of edge detail in a picture?
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:thumbup:
jacksterp said:
Fascinating. If I hadn't seen it with my own eyes, I never would have believed it.

Thanks very much for all your work and experimentation!
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