You all ruined my Worksharp!

[Obsessed with Edges]

I wrap my sandpaper around a deep bucket paint stirrer, folds nice and creased to make it fit pretty tightly. The paint stirrer is a hard enough enough wood (I think pine) so there shouldn't be anything that would happen with a soft backing like leather or a mouse pad. I'm pretty sure that what I am getting happening is unusually deep scratches from my diamond stone that aren't being taken out by my sandpaper. I visually inspect the edges after every grit, and off the XC my edges are clean looking, with no apparent deep scratches. It could also be that the burr is being ripped off by the coarse sandpaper, because I don't work it down on the low grits (sub 800), I just work a burr on both sides and then move up.

There's a big change in aggressiveness of the sandpaper, just in sticking it firmly to the backing to keep it from moving at all. When I first started experimenting with sandpaper sharpening, I started with the paper just wrapped around my strop block. Eventually noticed the issues I mentioned earlier, and that's when I started progressing towards a firmer setup, doing like you've done, with paper wrapped (but not stuck) around hardwood, then eventually using some temporary adhesive to stick the paper down. Things noticeably changed for the better when I did that, and the progress continued as I started doing the same with progressively harder backing (glass, and I sometimes have used a granite reference plate similarly). When the abrasive can no longer move at all, either down into the substrate (too soft) or laterally under the blade (slipping or lifting from the hard backing), that's when it starts really digging aggressively and efficiently. Edges produced by doing so will be a lot crisper and cleaner, at least with steels that aren't high in VC content. For those, I'll go to the diamond.

I've avoided using extremely coarse diamond hones the vast majority of the time, simply because the scratches they produce are so very tiresome to remove. Looks like you're noticing this too. Unless I were sharpening a very large and/or very thick blade, and needed to remove a ton of metal, I'm content to use nothing more than a Coarse diamond for re-bevelling and similar heavy grinding tasks, even if it takes a bit longer to get it done.


David

 

[dkb45]

This is definitely sounding like a sandpaper set up was good for an introduction to manual sharpening, but the nuances and requirements to get a proper edge are a little more than I am willing to do. The diamond plates I am ordering come with a DMT Manga Guide, so I should be good. I will have the guide when I want to use it, and stones with nice handles so I can hold them for better control.

 

[dkb45]

I... am stupid. The micro chipping on my Bionic was bad enough that it would catch on phonebook paper, and I was thinking I would have to completely redo the edge I am pretty proud of (aside from the chips)... idiot me didn't think to take my strop, add a little black compound and just strop it. Turns out that just a little work on the black compound took the chips completely out. There are still some deep scratches, but since the edge is slightly rounded the edge is completely intact and my knife now slices tissue paper. No push cutting, but a step forward is still a step forward.

 

[Clan Gunn]

Tagged for great info and return. Would like to learn more about the sandpaper method. Also I have a Makita wet stone sharpener w/ the three wheels; any way this can be used? Is it important which way the knife is presented to the direction of rotation?

Also have the 6 X 48 belt sanders, can these be used without over heating a blade?

My Dad was a very skilled carpenter/cabinetmaker, did all he's sharpening freehand. No way can I do that. A large part of my problem is the time it that's, even if I knew how to do it.

Thanks

 

[HeavyHanded]

Tagged for great info and return. Would like to learn more about the sandpaper method. Also I have a Makita wet stone sharpener w/ the three wheels; any way this can be used? Is it important which way the knife is presented to the direction of rotation?

Also have the 6 X 48 belt sanders, can these be used without over heating a blade?

My Dad was a very skilled carpenter/cabinetmaker, did all he's sharpening freehand. No way can I do that. A large part of my problem is the time it that's, even if I knew how to do it.

Thanks

No doubt it goes faster with powered equipment, but you might be surprised how fast you can get freehand, especially if not working the high carbide steels. Once you get a good idea what you're trying to accomplish at each stage you can fix all but the most hammered edges in very short order, under half an hour.

 

[Chris "Anagarika"]

Tagged for great info and return. Would like to learn more about the sandpaper method. Also I have a Makita wet stone sharpener w/ the three wheels; any way this can be used? Is it important which way the knife is presented to the direction of rotation?

Also have the 6 X 48 belt sanders, can these be used without over heating a blade?

My Dad was a very skilled carpenter/cabinetmaker, did all he's sharpening freehand. No way can I do that. A large part of my problem is the time it that's, even if I knew how to do it.

Thanks

Checkout HeavyHanded's washboard. Highly recommended for it's versatility and great for learning as well due to enhanced feedback. The video he shot also helps a lot. :thumbup:

 

[HeavyHanded]

Tagged for great info and return. Would like to learn more about the sandpaper method. Also I have a Makita wet stone sharpener w/ the three wheels; any way this can be used? Is it important which way the knife is presented to the direction of rotation?

Also have the 6 X 48 belt sanders, can these be used without over heating a blade?

My Dad was a very skilled carpenter/cabinetmaker, did all he's sharpening freehand. No way can I do that. A large part of my problem is the time it that's, even if I knew how to do it.

Thanks

If interested in learning a bunch more about working with sandpaper, there are a handful of shorter videos linked through the sale thread in my signature below. Is all shown with my sharpening block but can be applied to sandpaper over most hard surfaces. The first video details how the Washboard is different from other tools, the rest - while demo'd on the Washboard, are of a more general nature and will be pretty helpful starting out.

 

[Clan Gunn]

Thanks HeavyHanded, have started watching the video's. Nice to see you sharpening a plan blade.

 

[xaylin]

I have always sharpen my wood chisels (and knives with micro or flat/scandi grinds) on a piece of plate glass with wet/dry sandpaper. you can usually get it to suction down to a smooth, flat surface with just water (I keep a cap of spray adhesive handy though). You can also get a granite or marble sink cut out scrap from a counter top company for free/next to nothing and they work well too. Usually by the time I get to 4000 I can see my face in the bevel. You can go really nuts and get down to submicron (12000 grit) sandpaper and you will get a glass like surface.

Sandpaper is probably more expensive in the long run, but you are always guaranteed a flat sharpening surface.

 

[HeavyHanded]

Thanks HeavyHanded, have started watching the video's. Nice to see you sharpening a plan blade.

Yeah, that was a special request from a good guy that bought one of my boards and wasn't confident how to approach a chisel grind. I don't own any except for my woodworking tools, so there it goes. I used to do those on an India stone and finish them off on my board, but after doing that video I just use my Washboard for everything.

Am going to schedule some time on my Jointer stones and waterstones in the near future just to make sure I'm not forgetting anything, but the WB is so much more convenient - especially when my bench is piled high and I'm in a hurry.

 

[dkb45]

Got a new question. While my edges are very sharp off the stones, stropping should still give me a sharper edge, but when I strop I take all the bite out of my edge and it doesn't cut as well. Only leather stropping gives me a sharper edge.

 

[HeavyHanded]

Got a new question. While my edges are very sharp off the stones, stropping should still give me a sharper edge, but when I strop I take all the bite out of my edge and it doesn't cut as well. Only leather stropping gives me a sharper edge.

Stropping in general doesn't necessarily give a "sharper" edge, it creates one that is more uniform. When coming off the stone, there are irregularities along the apex that catch on materials and will have more bite on many materials. The peaks of these irregularities are going to be very sharp across the tops, and the cutting edge becomes a little wider as you head in to the valley. Stropping erodes the tops from these irregularities and makes the edge more uniform, will also bring some of the lower points to a finer terminal edge, but at a somewhat more obtuse inclusive angle. In most cases this is why you shouldn't bother stropping an edge unless its already fairly refined and when you do so you're changing the character of the edge from something that catches on a draw, to something that penetrates more efficiently on a pressure cut. That is a general statement, there can be plenty of overlap, but in general...

There are exceptions to this when stropping on other surfaces than a leather or textile charged with abrasive (softer waterstones, hard backed strops), but then is more of a backhoning action. The harder the backing the deeper the abrasive will bite into the steel and the more pronounced the edge effects will be.

Stropping on plain leather, paper, materials not loaded with hard abrasives, will generally leave the irregularities untouched and just provide a fairly mild form of deburring with a slight polish. Good for a finish step if the edge is clean, not very effective for longer term maintenance.

 

[Obsessed with Edges]

Got a new question. While my edges are very sharp off the stones, stropping should still give me a sharper edge, but when I strop I take all the bite out of my edge and it doesn't cut as well. Only leather stropping gives me a sharper edge.

What are you using for stropping (which compound on which substrate), specifically? And on what steel(s)? If wanting to add additional sharpness or alter the finished character of the edge, choosing the right combo of compound and backing makes the biggest difference. If compounded stropping is degrading your edge by taking the 'teeth' out of it, or otherwise diminishing it's performance, that's when I'd be looking for different compound, or backing, or both. Finding the best combination for the specific steel being worked can really take sharpness up another notch.

HH's explanation is first-rate, in delineating the differences between bare-leather stropping and the 'backhoning' methods using hard-backed strops and aggressive compounds. Bare-leather stropping will basically 'clean up' the weakened remnants left by the stones, and not do much else in terms of altering what's left. When I see an immediate improvement in my edges from bare-leather stropping, it confirms to me that the work done on the stones (and perhaps intermediate compounded-stropping steps) was good, and some or most of the weakened tatters (burrs, etc) are being scrubbed off the edge. Those remnants impair the cutting performance of the honed edge, hence the perception that the edge gets 'sharper' after scrubbing them away on bare leather. I view bare-leather stropping mainly as a 'tidying up' step, before calling the edge 'ready'; sort of like a woodworker will wipe away any loose splinters and sawdust from a project ready for finishing, after all the cutting, shaping, drilling, assembling and sanding has been done.


David

 

[dkb45]

The compounds I have are Flexcut Gold, green CrO, and some black compound of unknown material. I know I should invest in CBN or diamond pastes for working vanadium steels, but I,just,can't afford that stuff.

 

[HeavyHanded]

The compounds I have are Flexcut Gold, green CrO, and some black compound of unknown material. I know I should invest in CBN or diamond pastes for working vanadium steels, but I,just,can't afford that stuff.

Pick up some diamond lapping film and strop on that, is about $6 a sheet for the 6"x6" stuff, plenty large enough for occasional use or finish work. Or just don't strop the high VC steels - clean them up on the stones and let it go.

 

[Obsessed with Edges]

The compounds I have are Flexcut Gold, green CrO, and some black compound of unknown material. I know I should invest in CBN or diamond pastes for working vanadium steels, but I,just,can't afford that stuff.

What steel(s)?

More often than not, when I see an edge get duller or too polished to cut well, after stropping, it's likely due to the substrate being softer than is ideal, and the choice of compound sometimes aggravates that as well. For example, I have some 'black' emery compound that's very aggressive for it's small particle size (1-3µ), and polishes very quickly. I've not used it much, because it tended to be much too aggressive when used on leather or other relatively conformable backing. The end result was much as you'd described, with the edge becoming very polished very fast, but the 'bite' was gone.

A similar result has sometimes happened when I've used green compound on leather, for stropping fairly high-wear steels like D2 or S30V. The compound doesn't cut the carbides in those steels as well (perhaps not at all, for the vanadium carbides in S30V), so the end result was a gradual rounding off or burnishing of the edge. Using the same compound on hard backing might've worked slightly better, but the basic choice of green compound for high-wear steels was not the best selection in the first place. This is why I've SWORN to never use anything other than diamond for S30V (or CBN, if I had it), and nothing else. And I generally won't use green compound for anything more wear-resistant than 420HC or 440A, BUT it works excellently on those and anything less wear-resistant, like 1095 or CV. For most all of the 'in between' steels, in terms of having wear resistance higher than 440A, but lower than S30V, I'm learning to really like the AlOx compounds (white rouge, and at least some of the 'grey' compounds) for them. I'd assume this would include the Flexcut Gold compound, which is AlOx-based, though I've not yet tried it.


David

 

[dkb45]

The steels in question are carbide steels, namely Elmax, S30V, and M390. I can stropping ZDP, 154cm, and D2 normally because of no vanadium carbides.

I guess I should get some lapping film. Cutting the sheets down should make one last a while, at least long enough to get some spare cash for pastes.

 

[NRA]

It is not so much that any girls at a dance, can dance, or not dance, it is how she gets along with her dancing partner.

The machines are not sharpening anything, you are.

It is your dance, with the tools, that does, or does not, sharpen.

Some people dance with this tool best, and some people master other things.

My experience with WS has been pretty good.

I measure my score on a blade sharpening system, not by what it does to a piece of paper, but what the blade edge does to my eyes when I gaze upon it.

If the blade has a pleasing look to it, I can tell if it is sharp, or if I am off, or miles off.

The WS system, is quick, easy, and easy on my eyes.

Results are again and again, across all types of blades, repeatable. Consistent.

If you master sandpaper, you have got one of the best systems for affordability, portability, and dependability. My problem with sandpaper, is it hurts my artists eyes, to gaze down upon the scratches I have on the blade, that has nothing to do with being a sharp blade. Just me

 

[AFAustin]

NRA said it well. We all have somewhat different goals in sharpening beyond just getting a sharp knife---learning an ancient skill, learning how different steels react to different media and methods, helping out family and friends with their dull blades, etc., etc. I likewise really enjoy a good looking edge.

While I don't have the skill or patience to get the perfect mirror edges that some of our brothers achieve, I still like to see an end result that is symmetrical, polished, pointy, and sharp. It is rewarding and enjoyable and I can get that most often, most consistently, and in a reasonable amount of time, with my WSKTS KO.

Andrew