Work Sharp 3000/diamond discs/establishing chisel surfaces...

[Warren Mickley]

I have to agree with David that a feel for stropping can come only after a good deal of experience. I don't think you can get a feel for it by reading blogs. Honing on water stones, honing on Arkansas stones, stropping with compound, stropping clean, etc. These are not equivalent operations.

[ian maybury]

That's for sure Warren. What I was suggesting (because others may be my situation) was that as a person who having got to the point of having a waterstone set up that is working well on carbon steel, and has just been steered towards a possible next step (stropping on MDF - thanks David) the penny has dropped to the effect that stropping is more than just some sort of one size fits all standardised next step beyond honing. That care is needed to fit any 'next' step method with the earlier ones, because it's not necessarily going to an improvement.

It's from a distance easy to see it a bit that way, especially if like me you've been hand sharpening tools for yonks using oilstones and/or relatively coarse diamond plates (locally common box store stuff) for use in less demanding construction type situations - and not until fairly recently come to appreciate the very high levels of sharpness obtainable from carefully working a good blade down to the finest of grits on e.g. waterstones.

It looks instead as you say that there's multiple varieties of both honing and stropping, and many paths to sharpness. The issue for somebody relatively new to the territory is that it's not practically possible to test all the options - yet it looks as though not all honing techniques are suited to all stropping options.

I guess in absence of having a teacher to hand reading blogs and forums sure beats being left entirely in the dark...

[Derek Cohen]

Frankly, brent beach doesn't know enough about stropping to really know what he's talking about - the first clue is that he associates stropping only with using compounds, and doesn't describe why people would strop to begin with (I'd imagine he's unfamiliar with natural stones). He also seems to be unaware that there are powders and compounds widely available down to .05 micron (that's not a misprint). I have no idea what beach would do if he were faced with an incannel gouge, or any gouge for that matter. he might find strops very useful if that were the case.

At any rate, i don't generally use those compounds because they're not necessary, and also for the reason you mention - I'd rather do the heavy work with a stone and preserve geometry and control it so that the next wire edge is raised easily when I sharpen again. When I strop, it is with clean bare leather.

Stropping itself is another thing that you will get a good grasp of only with experience, to improve an edge with it, and to figure out the things it works with well. It is my opinion that it offers little on the very hardest of steels, but on vintage steels, it provides quite a gain. The same is true with razors. The super ultra hard razors do respond a little bit to a strop, but not so well as one that is medium hard.

All of that said, what brent doesn't give much of a nod toward is how sharpening actually fits in a work flow, with various shapes of tools and in the context of actually doing work and letting results dictate technique. I can't imagine having to stop and use his process in the middle of a session preparing a large rough panel. His pointers are useful to show that some of the popular compounds do have large particles in them, but the suggestion that graded chrome ox is too slow is only worthwhile if you're actually trying to use it to cut steel at a significant rate - which isn't its use, either. (it's a lovely thing for razors, if the razor is brought to it sharp already).

At any rate, my suggestion would always be to look at what the folks doing what you're doing ...do. If you're preparing boards from rough, find out what joiners and cabinetmakers do/did to sharpen. If you're carving, find out what carvers do. If you're sharpening and stropping a razor, find old barbering texts. The answers will often be different when in the context of the work than they are outside of it by someone trying to parameterize everything.

Anyway, the reason you might like MDF on the WS is that it's a bit harder than leather, but as it loads it becomes slick and it doesn't threaten geometry. I've got a 6" leather wheel attached to the disc on one of those junky combination belt/disc sanders, and while it works, it's no quicker for me than stones and because of the power aspect, it has an appetite for disregarding the geometry you've carefully set up on an edge. Once geometry is right, you only hone out wear, except in extreme cases where you want something like an ultra thin low-angle paring chisel or something. Parsimony in wear and in removal of steel, and preservation of geometry, while doing great amounts of work becomes infinitely more satisfying than mass removal methods.

Ian, I have linked to David's post as I think it is so excellent. I support everything he has said.

I want to point out that you have done a fine job, but I would never power the backs of my Japanese chisels (by back I refer to the hollowed side). Why? Simply because it is not necessary, and potentially damaging - for example, You have already removed more of the ura than I do, and here I am referring to the lesser removal! There is no harm done at this point, but go very carefully on the one with the wide flattenned area in front of the ura. In my own case, I rarely have more than 1/8" showing.

Hand flattening is about control. It is far too easy to go too far with something like a Worksharp. Use it on bevels by all means, but not the back. In any event, the design of the Japanese chisel makes flattening so easy by hand - but you sometimes need to start below 1000 grit. I use 1000/6000/13000 grit, and then a swipe on a bare leather strop to ensure the wire is gone. I only ever use the 13000 on the backs , and a few swipes are enough to keep the ura at bay.

The point that must be emphasised is that sharpening is a personal matter - eventually one must do what is comfortable and fits in with the why one works. This means that there is no right or wrong method. What happens is that we improve efficiency over time. There is nothing wrong with Paul's rounded bevel or Warren's flat bevel. They all work efficiently for them. But they may not work efficiently for someone else. I hollow grind my blades - Japanese included!! That is blasphemy for some, but I don't care. With the Tormek's large wheel I am not affecting the strength of the edge, and I can freehand my blades more easily on the full hollow. It works for me. It is efficient for me. You will find what is efficient for you.

Regards from Perth

Derek

[ian maybury]

Thanks Derek. That seems to reinforce what David said on careful stropping and sets up some directions to try. i.e. that a finely honed edge needs care and light handling. For sure it's a journey of discovery.

For sure also a slip on the WorkSharp could result in serious damage - all it takes is a moment of inattention leading to popping a chisel down nose first. Or getting impatient, leaving the chisel on for too long and allowing too much heat to build up. The abrasive discs lose their cut pretty quickly too. Extra care IS needed on very narrow chisels. Against that the 120 grit Shapton used to flatten the back of the wider of the two chisels in the photo was quite a bit slower - and it feels a little odd in use when loose grits build up on the surface.

So far those are just the options I happened to have to hand for back flattening. It's very possible that there's a better one - maybe a coarse diamond plate (which might need some finer intermediate steps to remove scratches?), or the more traditional steel plate with a grit that gets progressively finer with use to deliver a fine finish.

The WorkSharp is not aggressive compared to e.g. a dry grinder - it runs about 600rpm and on 120grit it's still quite slow. I found I was able to establish a flat from the rear, and then over multiple very brief cuts with pressure a bit more towards the middle/front (not so much as to let it rock forward) have the ground area ease forward until it just reached the edge. The surface produced is nice and flat. Another advantage is that it's possible in a moment to switch to a finer grit to slow it down some more, or as a second step (400 grit in my case) to refine the surface and reduce the work subsequently required to get the 1000 waterstone cutting over the entire area. (so far the surface has always been flat enough that it's only a matter of removing the texture left by the 400 disc on WorkSharp)

Re. the photos and the flat between the edge and the hollow. There's been no more material removed than was necessary to flatten the backs. What did cause some bother and cost some metal (not sure if it's normal with Japanese chisels - suspect not ?) is that as previously mentioned all of the backs done so far (8) were to various degrees humped - with the high area roughly 15 - 30mm behind the cutting edge. Some quite markedly - tipped back so that the rearwards half of the back was flat on a surface table the cutting edge was lifted typically by 0.004 to 0.009in. (measured by feeler gauge)

As I figured it there was a choice - either settle for flattening the back for only the first 30mm or so (and remove minimal material), or remove a bit more and obtain a flat surface over the entire back. Having never seen anything but the latter done in pics and sharpening write ups about Japanese (not necessarily it seems on Western) chisels (and feeling that a longer flat improves stability when cutting) I chose to flatten the entire back….

ian

[ian maybury]

Just a word of caution re the above for anybody setting up high quality Western chisels - or for that matter Japanese chisels with flatter backs. Bear in mind also that it doesn't apply in the case of plane blades.

It's reporting experience in working up a set of Japanese white steel chisels with not very flat backs. The likelihood is that if you are starting with either of the above that it's not going to be a big deal to flatten the backs using waterstones (as in the Lie Nielsen chisel sharpening video) - and by doing so to avoid the risk the guys mentioned of a slip of the hand causing damage - or of overheating if impatience sets in and it's not lifted off quickly enough.

The other side of the coin might arise if trying to flatten badly out of flat Western chisels. If it turns out that there's a significant amount of material to be removed over quite a large area, or if it's a particularly tough (alloy) steel then 120 grit on the WorkSharp (while probably as fast as most dry options that don't risk overheating) could prove quite slow. Probably not if it's only required to flatten a small area behind the edge though.

I guess in the end all of these methods have their limits, and as such are more or less suited to particular situations and/or working styles. Which brings us back to the guys comments about the key role played by experience.

The ideal for flattening backs and putting on bevels has got to be some mythical zero wear water cooled and speed controlled device of some sort - one that permits grinding away without fear of overheating, while adjusting the rate of metal removal to suit the situation. Water cooled and horizontally mounted diamond disc anybody - with a work platform and optional fixture mounting tool bar?

[ian maybury]

Just to communicate a snippet of info on choice of sandpaper for use on the Worksharp discs. The diamond lapidary discs (see above) are still on the way from Hong Kong - but in the meantime my stock of OEM WorkSharp discs is used up and something was neeeded to get by with in the interval.

The OEM discs are very expensive from the UK, and the situation is worsened by the fact that Worksharp don't seem to offer then in single grades so it requires buying the coarse selection pack with only a few of the required grit in it - and lots that are of no use in my regime. (a well established marketing ploy - buying selections of any sort of consumable rarely works out as the uncommon sizes are typically left unused)

I bought self adhesive silicon carbide discs (the commonly available black wet and dry paper type), and ran some tonight. They get the job done, and cut very similarly to the OEM Norton discs (white 120, red 400) while fresh - but unfortunately lose their cut very quickly and last probably only about 1/5 as long. A right PIA to remove from the glass too.

So for anybody buying open market alternative discs - it seems there's something a little special about the OEM Norton discs - presumably the type of grit, and also the use of a low tack contact adhesive…...


Bear in mind that all of this is for bevel grinding and back flattening of Japanese chisels as above - using 120 and 400 grit to form the surfaces before switching to waterstones. Using the top mounted wide blade platform accurately levelled to the cutting surface of the disc means that Japanese style single bevel sharpening is very easy. There's no need to change the honing guide setting before switching to the waterstones - they end up cutting the bevel in exactly the same plane as did the WorkSharp.

[David Weaver]

You're getting typical experience with silicon carbide vs aluminum oxide. SC is very friable, and the grit breaks down quickly, but stays sharp as it breaks. Quality aluminum oxide is a bit softer but much tougher (there's a million different aluminas for different applications, but all that I've used are pretty tough compared to silicon carbide.)

Its a shame that the work sharp model is similar to the consumer printer model (expensive consumables), and vat plus import can only make it worse.

[ian maybury]

I wasn't sure what the WS/Norton abrasive disc was David, but that sounds very much like what was going on. It's white, so maybe it has a non clog additive/coating or something.

Some digging a few months ago seemed to suggest that zirconia was a good choice for sharpening. The trouble is that over here in what's a very small market many of these items are not available unless you order a full pack - which means that you need to know what you are looking for. First step is to try the diamond discs when they arrive.....

[David Weaver]

I think for sharpening on a moving wheel, the aluminum oxide will get you the most per unit of currency spent (though maybe from an alternate source than the super marked up and then imported and taxed worksharp branded stuff - maybe cut your own out of PSA aluminum oxide that's available).

The fact that silicon carbide breaks off and stays sharp is great, unless it's breaking into little sharp pieces a tenth of the size you actually want. Aluminum oxide is probably the best inexpensive abrasive for sharpening tool steel, thus its use in waterstones and india oilstones and on sandpaper.

I've used the blue zirconia and I think in a grinding situation like someone grinding a knife where there's no hard backer, you might get your money's worth but I'd be willing to bet that sharpening a chisel against a hard platen, you won't. I bought belts of it to lap planes a long time ago, and I don't think it lasts any longer than good quality aluminum oxide for that, but it's significantly more expensive.

I think you'll be fine with diamond and aluminum oxide, especially now that diamond is cheap. As long as you keep the grinding temperature down with the diamonds, and the pressure light.

[ian maybury]

Thanks David, good to get the feedback… Will hold fire on the zirconia.

[David Weaver]

Thanks David, good to get the feedback… Will hold fire on the zirconia.

I could be wrong since it involves power. My experience was with hand lapping, and i know with light pressure and no backer, the zirconia does last quite a bit longer - it's specifically made for that. I just don't know what level of pressure between its designed application and hand lapping that a big difference occurs. You'd have to tally what you're doing vs. aluminum oxide to really get a quantified idea of the additional durability to see if it's near zero or of it's a lot.

No clue what the blue zircon material would cost there in something you could affix to a disc, but one nice thing about al-ox of good quality (like the gold stuff or norton 3x) is that it's almost always on sale somewhere. I can get belt grinder belts in al-ox here for less than a dollar if I keep my eyes open (1x42) and they are easy enough to change that even in that specific case, the al-ox is cheaper than any blue zircon I can order.

Safe to say, though, the silicon carbide is to be saved for something where the actual hardness of the silicon carbide is needed, and with woodworking tools, that's a bit uncommon. Maybe some turning tools that are really really highly alloyed, but those folks have moved on to cubic boron nitride to cut some of the super hard carbides in their tools.

[Andrew Pitonyak]

for backs and bevels has worked well. (but a wrong touch when doing the backs could do a lot of harm)

Just to be clear, are you saying that you are able to flatten the backs with no problems.... but that you need to be very careful?

I had horrid luck flatten the backs on the worksharp. It just occurred to me that it might have worked if I had started by laying my blade flat onto the worksharp before turning it on that might have helped since my problem was lowering the back onto the already spinning disk.

Before I gave my worksharp to a friend, I was purchasing very course disks from a local store and cutting a center hole in them. It might have been around 60 grit. This very quickly established a bevel with minimal heat generation.

[Andrew Pitonyak]

I have the WS leather stropping disc, but it probably wouldn't be too hard to DIY or maybe improve one if needed by adding the appropriate piece of leather to one of the WS glass discs. Wonder how some bonded on MDF or similar might do for this use?

Not sure what I was thinking, but I purchased a bunch of leather from a local store.... I glued them to some hard maple that I had in my scrap bin.

[ian maybury]

No prob on the zircona David - it can be the reserve. The WS runs pretty slowly, and I've been using light pressure. (580 rpm)

Hi Andrew. Yes, I've been finding it does a very nice job of flattening the backs and setting the bevel angles on Japanese white steel chisels using the 120 grit WorkSharp discs, and then taking out the marks using a 400 grit disc befor finishing on the waterstones. (1000 and finer) It's producing a nice flat surface that cleans up quickly.

It's not all that fast (maybe a few times faster than the 120 grit Shapton), especially since I've been working in very short bursts of say 4 seconds at a time for fear of heating - dipping in water every time and drying with a rag before cutting again. (it keeps the main body of the chisel cold) I may have been a little lucky - in that they probably don't require an aggressive a cut compared to say an out of flat Western style chisel to get the job done - which reduces the risk of a mishap. I don't think I'd want it any faster...

The key as before is to take care when lowering the chisel on to the disc. Get it level in both directions and a hair low at the back so that the edge doesn't get dubbed, and maybe 2mm above the disc - then place it. Take care where you apply (light) pressure - too much to the front would not be a good move if you have a humped back as it could rock forward. It's inevitable that this rear touches lightly for a moment before the rest of the back, so too fast a cut/coarse a grit could cause a problem there too.

I've done 10 so far without mishap - including a couple of mortice chisels and very narrow 4mm examples. The technique has become pretty automatic. The biggest issues I've had is that the discs quickly lose their speed of cut (it's a choice of spend a fortune on discs or be patient - they do keep on cutting for a while - but here's hoping the diamond discs will arrive tomorrow), and that the chisels (Matsumura white steel) are in parts pretty approximately ground. (no idea what the norm is in this regard for Japanese chisels) Meaning that there's quite a lot of material to remove off what so far has been a 100% record of humped backs. Most have been close, but a few have been way off on bevel angle as well.

The back faces and hollows in the backs of the mortice and very narrow chisels were misaligned/quite tilted relative to the cross section of the blades too, and needed straightening - they were finished off on the 120 grit Shapton after a quick touch to get them close for fear of overdoing it.

Another manufacturing related issue has been (despite mutterings in the blurb that they are supposed to be cranked enough that the shank - the bottom surface of the round section bit between the blade and the socket - doesn't touch the work/stone) that most have needed dressing with a die grinder to create clearance. This would otherwise tip them forward to dub the edge.

None have been stropped yet (waiting for the adhesive film to arrive), so it may not work out at all - but the rationale as earlier is that using a 3mm thick MDF disc stuck to the glass disc with double sided adhesive film may help preserve the edge geometry.

[Reinis Kanders]

I use foot pedal for my worksharp when I flatten backs. Works well. It was about 30 bucks from Amazon.