Testing Some Jasper Slabs

[SliceOfLife]

First one to get the shave test is a biggs that arrived mostly flat. Very hard, was a real pain to get the last of the saw marks out of it, and it's got a wobbly edge, but it's a reasonable size (a little small but ballpark barber hone size ~120x60mm or so effective area).


Polished it to a very worn 220grit DMT... so arguably fairly course finish, but that DMT has just the barest nubs of diamonds left, so it's actually surprisingly polished.


Took two razors to it. The first one I noticed had some edge pitting so it got put aside in favor of the second which will be shave tested.
Maybe because the finish is 220 dmt and not ultra-polished 1600wet/dry or something like that, but it actually felt like it cut decently... 25-40 passes the feedback told me we were good to go, but I overshot it just to be safe.

The shave test will tell if this is reasonable at all or if this thing requires a finer prefinish than 3 micron.

And then even if things work out I'll need to see way down the line if it stays an effective cutter as it wears in and the scratches from lapping fade or if it's just a file that requires surfacing to cut well.

Pictures of edges:
8k DMT + palm strop
30ish passes on jasper
100ish passes on jasper

Second razor 8k + palm strop
70ish passes on jasper
100ish passes on jasper.

 

[SliceOfLife]

Shave was great.

49.5/50 sharp... light saber.
48.5/50 comfort... a bit of aftershave burn, but no other complaints.


For a stone that costs roughly $15-20? Incredible results. Downside being it took a bit of work to smooth and the shape isn't conducive to honing... but that can be fixed by being more discriminating in the slab you pick... an absolute steal.

As noted... the concern is does the stone stop cutting when the lapping scars go away? We shall see.

I've got like 4 different types/regions of jasper to test, so I'll have some fun seeing if/how they differ.

 

[kcb5150]

The apache black gila I have really works best when the surface is kept matte.

 

[SliceOfLife]

So this one is from the same lot... is about 5.5x3" with a fairly straight edge... arrived flat and usable, seller indicated he thought it was an Owyhee.

Shave test will be tomorrow, but I ran a razor over it and the flaws/faults don't seem to catch or do anything. Stone definitely feels coarser. Edge seems to show that as well under the scope... and HHT bears that out as well. Still passes HHT well and looks like it may give a good shave, but appears a noticeable step down in sharpness. The shave tomorrow will tell though.

 

[SliceOfLife]

Shaved off a Calligraphy Slab today.

Slab didn't lap up well. Much softer, and the small red areas between the leaf fossils crumbled away at parts.

Under the razor it felt like it wasn't smooth. Not quite gritty, but irregular surface. Also generally felt coarser.

Bevel still polished up a lot, but edge shows a lot more damage.

And the shave was what you'd expect, and what I remember from Jaspers in the past... felt like a highly polished bevel but an edge that had taken a bit of a beating on the hone. Decent Barbers-synth tier shave. Not terrible, but not good.



Definitely looks like the particular jasper matters... but does region or appearance or what determine what makes one a reliable hone? I've got a few more to test that may help with that. So far one of the three Biggs I've got has tested to be quite good. And this Calligraphy tested to be not really worthwhile.

 

[SliceOfLife]

Just got this guy lapped... Clean and as hard if not harder than the Biggs. Shows promise.

 

[global_dev]

Just got this guy lapped... Clean and as hard if not harder than the Biggs. Shows promise.

Sad to hear about the calligraphy, looks too cool. What did you lap it too?

But i like the 2 tone even better. Cant wait to hear feedback.

 

[SliceOfLife]

I'm only using my 160 and my 220 diamond plates. they're very worn though so the polish is actually pretty good... Any sandpaper under 1000 is a pretty clear step back.

I took some sandpaper and 400 and 600 to the calligraphy and it really chewed it up so I switched back to the diamonds.

Sandpaper including a belt sander barely touches the other ones... I tried to knock a little hangnail piece remaining from where the saw hadn't cut through all the way on one off on my 200 grit sander and it didn't seem like the sander was cutting the stone or the stone cutting the belt... Think it was an alox belt so I would guess that particular Stone which is the two-tone one was ballpark as hard as alox.

The big one arrived and I just got it polished up. it's not quite as hard as The biggs was ... But it's very close . Feels almost as fine maybe just a hair under where the biggs is, but definitely more of a tooth to it reminds me of a hard jnat and the Apache strata a little bit in use.


Edge looks good also.



To give an idea of how hard these stones are. This one was pretty clearly lapped completely flat on sic I would guess 40 or 60 grit sic (or similar loose abrasive) it still took about 40 minutes on a 160 grit diamond plate to get it polished. And The biggs was probably even a little harder than this one.

The calligraphy wasn't exactly muddy but it felt muddy in comparison.

 

[SliceOfLife]

So that Big Picture Jasper shaves well, but not as sharp or as comfortable as the Biggs...

46/50 close
46/50 comfort
92/100 overall

I'll see if it breaks in to improve at all, but so far the Biggs is the standout.

Two tone tomorrow then the ohywee I'm thinking. Then probably best two will face off for a confirmation match.

 

[SliceOfLife]

So honing on that two tone now. It is too slow to practically go to off 8k DMT... so I'm taking near-finished razor to it. It is Slooooooooow. Nice feedback, but hardly cuts at all.


Scoped stropped and scoped... it's too fine/slow. Edge wear outpaces edge refinement. Like honing on a piece of glass. Maybe with slurry it'd be a usable stone... but just not enough abrasion to keep up with the wear honing on water puts on the razor.

 

[Tomo]

Great experiment. It’s not selling me on Jasper though. It sounds like it’s best to stick with the usual suspects.

 

[SliceOfLife]

So far these are the three that I've got my hopes on right now. The biggs has worked really well I have two more that I'm going to lap up and test at some point. The picture Jasper worked fairly well, but I'm going to try to polish it a little more and see if that improves. The last Stone which was supposedly a ohywee, but we doesn't look like the other ohywee I bought is still untested and will probably be my shave tomorrow.

The last stone has some faults, a crack and some pits in it. The first razor I took to it didn't show much damage from them... the one I just honed seems to have, but tomorrows shave will tell. Day after tomorrow If I have time to polish the picture jasper some more (it is a BEAR to lap/polish), I'll give it a shot at a higher polish level.

 

[SliceOfLife]

So this thing just ate an entire sheet of high-end sic wet/dry 3000 grit sandpaper in about 30 seconds and it smelled like a ball of burning hair and super glue while doing it... So that's as polished as it's getting. I'll give it a round 2 tomorrow, then maybe the third Stone the day after.

 

[SliceOfLife]

So here's what I was afraid of... with the extra polish on the picture jasper above it's definitely finer... but now it's starting to pull a wire like the two tone was. It's a very subtle one and I think it's manageable, but it doesn't bode well for the Biggs as it starts to wear in and loses the "tooth" my lapping left it with.

I got the picture jasper to put up a finish that has a barely noticeable wire after stropping, so we'll see how it shaves tomorrow... but yeah, definitely starting to see why these aren't popular hones, and it's pretty much what I remembered... if they get overpolished or too broken in they just don't cut sufficiently fast. With how hard they are, something like the biggs could probably get a good amount of use before it needs to be cut back open on a DMT... but the exact maintenance schedule will remain to be seen. I'll throw a 2000 grit finish on it next and see if it starts pushing up a wire too, but I'll be very surprised if it doesn't, as this picture feels like it is more abrasive and it's still starting to run into that problem.


See the picture below...I was able to get the wire to almost nothing with a bit of change in my technique and some stropping (On the 3k polished Picture Jasper); but it's still showing a bit of wire @ this mag prestrop and the HHT definitely has a bit of a wirey feel to it.

I think I'll try the two-tone with oil too and see if that changes its behavior.

Edit: Oil does significantly improve cutting and reduce (though not eliminate) wiring on the two-tone... mind you it's still only DMT polished... but the wire is far less pronounced on oil vs water on it, see the second picture below.

Relatively little improvement on the picture jasper with oil vs water though... slightly better/less wirey HHT, but slightly more visible wire. Honestly falls in the range of "the same" in my book. Definitely not the level of improvement seen on the two-tone.

 

[SliceOfLife]

Lapped the biggs to 2k... No wiring effect. Looks like they may be special.

 

[SliceOfLife]

Shave off the 3k polished Picture Jasper definitely a wire edge. Looks like so far the Bigg's are the ones to look for. I've got one more coming I want to test, and I'm going to polish up the other two Bigg's to confirm they are equally successful.

 

[SliceOfLife]

So I'm skipping a shave today because the last couple weren't all that wonderful. But I got a new rock in. A big old 8 lb hunk of what was sold as "fancy" Jasper... Looks like an uncut low quality ruby honestly. Little softer than the biggs was but still quite hard took a while to lap even though it was again pretty flat just had a little bit of a dish in the center. Honing on it is like driving on a gravel road with wooden wheels... But it doesn't seem to be beating up the edge under 400x any and HHT is top notch just like with the biggs.

I'll probably shave with this tomorrow and then one of the other biggs the day after.

 

[global_dev]

8lbs??

 

[SliceOfLife]

8.9 according to the seller. I figure I lapped a few grams off, but I haven't weighed it. It's heavy. About 9x8x5 give it take.

 

[stone and strop]

8.9 according to the seller. I figure I lapped a few grams off, but I haven't weighed it. It's heavy. About 9x8x5 give it take.

Its so you can set it on the floor and hone from your chair.