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Thread: Grinding and shaping bevels

  1. #1
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    Grinding and shaping bevels

    I am still not happy with the time I spend restoring and repairing bevels on vintage or heavily used tools. I am growing a little desperate to find a way to speed me through sharpening so I can get back to projects. I have a Tormeck and a belt sander, which seem to produce flat facets across bevels that I wind up having to remove by hand. I am more of a sharpen by hand kind of guy, having used various of those techniques for many years. I bought a DMT Dia-Flat which does work, but after restoring a vintage Japanese chisel, several drawknives plus normal tool bevel maintenance the surface seems considerably less abrasive. I also find the Dia-Flat and my Sigma Power Ceramic #120 seem rough for normal bevel work or stone flattening. I have been thinking of buying a 400 or 600 Atoma, a combo DMT or Ez-Lap or maybe steel plates and diamond grit like those sold by Lee Valley.

    My regular stones are: Sigma Power #120, Sigma Power 3F Carbon #700 and three Sigma Power Select II's: 3,000, 6,000, 10,000. I have read every thing I can find on this site regarding grinding and stone selections, still I do not feel I have a good plan for getting the heavy work done. I use to have a Delta bench grinder but got rid of it in favor of the Tormeck and belt sander as I was seeing too much bluing on edges. I sharpen lots of landscaping tools: shovels hoes, axes, mower blades....as well as wood working tools. I recently tried Diamond Film sheets from Lee Valley, especially because they can be wrapped around wood dowels to sharpen the curved blades I use in green woodworking. I liked the film but it just does not seem to last long enough to be worth using for rough work.

    I sharpen all sorts of steel, Japanese white chisel steel, powdered metal on pocket knives and PM-V11, A2 on plane & spokeshave blades, Swedish high carbon steel, softer tougher tool steels... I feel like I need something between the Sigma 3F Carbon #700, which has been my workhorse, and the Dia-Flat & Sigma #120. I typically grind flat, actually slightly convex bevels, which I realize requires more work. My standard hand techniques do not seem to work well with micro bevels and hollow grinding would seem to require the removal of even more steel. My attempts to hollow grind on my Tormeck thus far have been dismal failures. Suggestions?
    Last edited by Mike Holbrook; 04-23-2014 at 10:08 AM.

  2. #2
    Get yourself another inexpensive belt grinder, and get a softer and coarser wheel for it. I can square off a vintage iron and regrind it with a pink surface grinder wheel (46 grit) without ever using water - I don't keep water at my grinder. I don't know where to find those wheels for cheap - chris G and I cleaned out WW supply (which only amounted to each of us getting a wheel) when they had camel pink wheels for $13, but woodcraft wants about 50 bucks for the same thing. Woodworking suppliers always seem to really nail us on this kind of stuff. 7" pink grinder wheels are available EVERYWHERE, but 6" are less common.

    Anyway, something aluminum oxide, coarse and relatively soft if you're going to do heavy work. Maintaining a bevel can be done with any wheel, hard or soft.

    When I refresh a bevel, even one with a totally gone hollow, I can take the tool and place it in my palm. You could still burn a corner with a pink wheel if you let the tool camp on the wheel in the same spot, but they (at least in the hardness my wheel is) are really forgiving.

    (I've been through everything, too - wet wheels, belt sanders, belt grinders, etc).

  3. #3
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    I am growing a little desperate to find a way to speed me through sharpening so I can get back to projects. I have a Tormeck and a belt sander, which seem to produce flat facets across bevels that I wind up having to remove by hand.

    My standard hand techniques do not seem to work well with micro bevels and hollow grinding would seem to require the removal of even more steel. My attempts to hollow grind on my Tormeck thus far have been dismal failures.
    Hi Mike

    First we need to determine what you are doing ... something is wrong here - the Tormek is one of the most reliable machines and you should not be grinding flats. Indeed, the reliability of the Tormek to reproduce a hollow at a specific angle is where it saves so much time. That is, where it may lack speed in grinding, it facilitates speed in honing since the hollows are so uniform, you can create minimal microbevels, and these require minimal straightening. This also ensures that you removes the minimum amount of steel when grinding or re-grinding a hollow (the hollow is also shallower on a 10" wheel than an 8").

    So what could be happening?

    Is your wheel dressed regularly, not just to clean it but also to level it with the tool bar?

    Is the blade holder running evenly across the wheel? If not, check the plastic bearing strips (circles) for wear.

    You mention a great number of other honing and grinding stones. Are you using these on bevels ground on the Tormek? I am confused how they fit in, unless they may be used on the backs of blades. Try and simplify what you want to do.

    Regards from Perth

    Derek

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    I typically grind flat, actually slightly convex bevels, which I realize requires more work. My standard hand techniques do not seem to work well with micro bevels and hollow grinding would seem to require the removal of even more steel. My attempts to hollow grind on my Tormeck thus far have been dismal failures. Suggestions?
    The amount of steel removed is up to the person doing the grinding. I read someone's impression of why blades were hollow ground being to save the edge tool makers of the embarrassment of having a convex ground tool. It is just that a round wheel will leave a slight depression where it touches metal. If it is properly controlled it will only remove the metal necessary to establish a new edge. A hollow grind offers much easier 'click' to feel when the blade's edge is on the stone.

    My power grinding, Veritas Mk II Power Sharpening System, produces flat bevels. Most of the time it is used on woodworking tools for rehabilitation of an old tool or to establish a new edge. It is often used on landscape/garden tools and anything else around the place that can benefit from a little abrasive maintenance. Heck, sometimes I even use it to round the ends of dowels.

    The way it is designed automatically produces a secondary bevel. I have been able to defeat this feature.

    It may be impossible to find one system that will work with every tool from different disciplines.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

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    Certainly I have at least a reasonable number of sharpening options, which may suggest, as Derek mentions, that there may be problems with how I am using the stones and machines I have. My strategy for the Tormeck or belt sander was to use them to establish basic bevels but to maintain every day tool sharpness with the collection of stones, which is a strategy I believe many on this site use.

    I thought the Tormek would be the answer for me and bought one at least a decade ago. I have made numerous attempts to grind with it and even posted my frustrations in the past here. I seem to spend way more time that others say is necessary and wind up with incorrect bevels, that is bevels that are not perpendicular to the edge of the blade. Once a bevel starts getting established the blade wants to continue ridding on that new face, if I succeed in moving off the incorrect face it seems like I am starting over except now I have to grind out the erroneous bevel. I use both a dressing stone and the small diamond surface dresser and check that the bar is even with the stones surface so I don't think tool setup is my problem. My best guess is I am using too much pressure against the stone in an attempt to force the blade straight. My issue may be uneven pressure as well as too much? I am thinking about trying again with light pressure, at least until I can see I have the bevel developing in the correct place. Somehow I think I need to develop a feel for how to move the blade over the stone. I can feel correct position on a flat abrasive surface, but a moving surface seems to throw me off. I seem to get similar results with belt sander/sharpener or the Tormeck. I think I do a little better with the belt sander, maybe because one can not use heavy pressure against belts.

    I think David Weaver meant to suggest a wheel/bench grinder not a belt "grinder" (belt sander)? I have not tried this route recently as I seemed to have even less success with the small, dry wheels than with the Tormek or belt sander in the past.

    Jim I will revisit the Veritas MK II. I have been tempted to go with a machine of that nature in the past, as I suspect grinding against a flat firm surface may feel more familiar to me. It is good to read that it can be used for larger bladed tools as I had doubts about that and recently I have quite a few longer drawknife, axe/hatchets, large knife blades to sharpen.
    Last edited by Mike Holbrook; 04-23-2014 at 1:48 PM.

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    Jim I will revisit the Veritas MK II. I have been tempted to go with a machine of that nature in the past, as I suspect grinding against a flat firm surface may feel more familiar to me. It is good to read that it can be used for larger bladed tools as I had doubts about that and recently I have quite a few longer drawknife, axe/hatchets, large knife blades to sharpen.
    I do not sharpen my draw knife or my hewing hatchet on the Mk II. My scythe also doesn't have a profile that could be safely worked using the Mk II. Regular axe and hatchets heads are a piece of cake. Knife blades are a bit tricky but can be done.

    As far as getting off square with the Tormek is there a blade holder to keep the blade square to the wheel? My understanding with wheel grinders is it isn't to make the edge as much as it is to reestablish the bevel after sharpening a tool on stones and losing the hollow grind.

    For me a flat bevel works fine as long as I keep after it. On most of my blades I do not use a secondary bevel or the ruler trick. This makes a touch up to an edge so much easier for the free hand sharpener.

    You shouldn't worry about the time it takes. My feeling is most people guess at how long it takes them to do something. Me thinks they guess wrong. Time flies when your having fun.

    Work on your accuracy, your speed will improve over time.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  7. #7
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    You're getting some good advice, but I'm confused. Isn't using the Tormek inconsistent with trying to put a convex bevel on the blade? I don't have a Tormek (yet), but share your feeling about trying to sharpen on moving abrasives. I have a 1 x 42 belt grinder, Veritas Power Mk II, and Baldor 7" bench grinder. The one thing they all have in common is that they have all led me to tools with blue edges.

    I have used the Sigma 120, Sigma 400, Cerax 320 stone, 3 kinds of coarse diamond stones, and diamond paste on Kanaban. None of them compare to 3M Gold PSA abrasive on a granite plate. The abrasive is expensive, but it comes with A-weight paper and a very thin layer of adhesive. In my opinion, that combination is critical to avoid dubbing. I use 80, 120, 180, and 400 grit paper. It lets me grind out chips, flatten backs, and establish primary bevels (with an Eclipse jig) quicker than with any other method I have tried. And the abrasive has never blued an edge. IMHO, diamond plates are slower and the Sigma 120 is messy, clogs easily, and leaves deep scratches.

    It would definitely be easier to buy a Tormek or learn to use my bench grinder properly, but until one of those two things happen, the abrasive on granite works.

    By the way, for backs I go from the abrasive to the 400 grit Sigma. For bevels I go from the abrasive to the 320 Cerax if I want to work the whole bevel, or straight to a 1000 grit Shapton Pro if I'm just doing a micro-bevel.

    One last comment. I just wonder if going from the Sigma 700 to the 3000 is too big of a step. Have you tried a stone in the 1000 grit range?

    I'll trade you my Veritas Power MkII for your Tormek.

    Steve

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    I have a 1 x 42 belt grinder, Veritas Power Mk II, and Baldor 7" bench grinder. The one thing they all have in common is that they have all led me to tools with blue edges.
    A few of my tools developed some bluing at the edge before my learning was complete.

    Most helpful was learning to count as I ground edges to know when a blade was spending too much time against the abrasive.

    Hot fingertips was another.

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

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    Steve I have not been using the Tormek much recently on my woodworking tools, due to the inconsistent results I was getting. Yes, the Tormek makes a concave vs convex bevel, although as Derek mentions above the larger Tormek wheels do not make as obvious a concave bevel as smaller wheels. I'm not sure I want to give up on the Tormek yet though Steve it has only been a decade or so ;-) but I will think about that offer.

    Apparently Jim has not had the bluing issue with his MK II. I have not had as much trouble with newer belts/abrasives on my belt sander, maybe there are superior techniques & abrasives for the MK II?

    I sent Stu a note a few weeks ago asking advise but he is apparently fighting a backlog from the new tax laws in Japan and has not been able to answer. I am afraid that the frequently long transaction period dealing with Japan might be worse than I want to deal with at this time so I was trying to find a way to use what I have or find something I can get sooner. I ended up with a Sigma 700 and Sigma 3,000 due to the fact that I had two weird Shapton Pro stone sizes, one of which had broken leaving me with only a 2,000. I asked Stuart about whether or not I might need a 400 or 1,000 back a ways but he seemed to think I had reasonable jumps from 700 to 10,000.
    Last edited by Mike Holbrook; 04-23-2014 at 3:32 PM.

  10. #10
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    Quote Originally Posted by Jim Koepke View Post
    A few of my tools developed some bluing at the edge before my learning was complete.

    Most helpful was learning to count as I ground edges to know when a blade was spending too much time against the abrasive.

    Hot fingertips was another.

    jtk
    You're right of course. Practice, practice, practice. Maybe I'll think about getting some flea market blades this weekend and re-installing the grinder wheel. My grinder currently has a leather wheel on one side and a felt wheel on the other. I could probably get a $50 buffer for those.

    Steve

  11. #11
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    I use the upright grinding belt gizmo sold by Lee Valley, when the going gets tough.

    68z7501s1.jpg

    Flat grind is easy with this rig.
    Care must be taken to keep the steel cool.

    For what the Tormek cost, you could sell it off to buy one of these
    and have money left over. There's even a powered stropping kit
    geared for knife makers, but I only use mine for grinding.

    Nothing gets my plane irons back to square faster, or more accurately.

    I think Derek Cohen had an interesting rig with an inverted belt sander that
    might be a less expensive way to test the concept.

    http://www.leevalley.com/US/wood/pag...84&cat=1,43072

  12. #12
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    Mike, as long as you already own the Tormek, you may need to pay more attention to the state of the grinding wheel. With continued use the wheel can get out of round and square making it tough to get an even grind, especially on plane irons. If you don't have the Tormek truing tool, that would be a good investment for you (TT-50). That is the improved truing jig. Also the latest Square Edge jig, the SE-76, is a big improvement over the ones that were supplied for earlier models of the Tormek. My Tormek is the older green model and I use it regularly to hollow grind chisels and plane irons to then be finished on waterstones. I use the set from Stu.

  13. #13
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    While I do have a "normal" grinder with those old blue-ish gray wheels, I also have one of theseIMAG0034.jpg Yeep, a $40 beltsander, stuck in the vise, upside down. That guide is the Veritas MkI. It stays on until all the steps i take are done. I just set the angleIMAG0030.jpgthen off to the sanding belt it goes. No blue in the edge, as my fingertips sitting right at the edge will tell when things are getting a bit too warm. The guide stays put while the stone work is doneIMAG0035.jpgand then on to the sandpaper ( up to 2k grit) on the tile. Then a few trips on that old leather belt.IMAG0036.jpg Done.


    The grinder has one rest set to 25 degrees to the wheel. It is for regrinding a very bad bevel, or I can sit the iron on edge, and flatten the back. Usually when a plane first arrives in the Dungeon Shop, the iron needs a LOT of re-work. After that? Maybe a refreshing after a project, or two. Doesn't take all that long, just a bit messy, is all. Oil on the stone is just good old 3in1 oil.

  14. #14
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    I thought about buying the Lee Valley belt sander, but I ended up buying one that had a number of features I was interested in. My belt sander allows me to move the mechanism that the belt rides on anywhere between 90 degrees to the work surface to parallel to it. I can clamp my belts in the same position Steven shows above just by loosing and tightening a toggle. Mine uses 42" belts but, they can be 1" or 2" wide. It also has a disc sander on the other side of the 1/3 horse Dayton motor. The issue i find with the belt sander has to do with the belt tending to wrap slightly around the object being pressed against it, which can dull the edge. Again maybe I am just: using too much pressure, not adjusting the belt tension correctly for the job....I have been free handing blades on mine. It has a 7" metal plate just under the belt. It also has a large and a small tool rest that can be set at various angles to the belt. Although I believe most belt sanders will produce a convex surface, I have the option on mine to work over a 5" in diameter wheel, 2" wide, which will produce a concave/hollow ground surface. I bought a selection of belts from a company that supplies belts for people who make knives, there is quite a selection available these days thanks to all those custom knife makers. I thought the Trizact belts were designed to run cool but I think Dave Weaver mentioned other belts were even better on a post not long ago?

    I am thinking more and more that I need to work on technique and specific abrasives for the machines I have rather than confusing the subject more with more options. I would love to hear more suggestions on how to use belt sanders and Tormek's more effectively, and thanks for all the good thoughts so far.
    Last edited by Mike Holbrook; 04-24-2014 at 9:52 AM.

  15. #15
    The only issue with the trizact belts is that if there is a hard platen under them, they will burn steel very quickly - especially in something with the belt speed of a viel grinder. If there isn't a hard platen under them, then you'll get a convex edge. I've actually never used another tool that made the edge so hot so fast as a trizact belt with a hard platen under the belt

    I actually like coarse grit belts on a belt grinder better if grinding is the purpose. The trizact belts work well if you are willing to tolerate the convex bevel, and are great for sharpening stuff like a knife that gets abused, or turning tools where the heat doesn't matter much.

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