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Thread: Veritas Mk2 Honing Guide Problem & Fix

  1. #1
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    Veritas Mk2 Honing Guide Problem & Fix

    Hi guys. Free hand sharpeners please look the other way.

    A Veritas Mk 2 honing guide bought a few years ago didn't work with my Japanese chisels (photo 1) - i've been getting by with the commonly used Eclipse type.


    It wouldn't reliably clamp/hold them - in fact it would hardly hold them at all. The slightly sloped backs worsened the situation, but it wasn't getting much of a grip on flat/parallel backed Western chisels either. A disaster - it's one thing that a honing guide must do well. Others have run into this issue judging by web comments.

    Thinking it'd be a pity to dump it given all the nice features and the cost (and having dug it out again i was eyeing the microbevel adjustment) the question became how to sort it out.

    The core problem (found in my example) is that the working surface of both clamps (aluminium die castings) is black powder coated. It's a very durable finish, but slippery as hell. The indentations in the surfaces look like they could both have been designed to be fitted with gripping pads which never made it into production…...

    This creates the possibility of a secondary problem - the clamp bar with the studs in will likely bend if overtightened in an effort to get enough grip - even heavy finger tightening visibly bows it. (both sides must anyway be evenly tightened on a flat backed chisel or plane blade so that it makes contact acros the width)

    Cutting back the working faces of both jaws on a fairly coarse diamond plate to create a flat bare aluminium surfaces results in a fix - a clamp that grips well. (see photo 2) Night and day compared to the original - and able to hold very narrow chisels too.

    While there's no reason to think it wouldn't, i can't say how bare aluminium would hold up over time - but it beats dumping the guide.

    Take care if heading down this road to ensure that the clamping surfaces stay accurately flat, and in the original plane. Tilting and/or out of flatness will mess up the bevel angle settings, grip etc. Hand filing probably isn't a good idea.

    The headed studs easily press out of the other half of the clamp and back in again (with a touch of high strength thread locker applied under the heads and kept well clear of the threads), so it can (but it's less critical) be flattened on the diamond plate too.

    The critical alignment on the guide (when using the cylindrical roller - it's not so important with the barreled version) is that the clamp holds the chisel in the same plane as the roller. (when viewed in the plane of the stone) Mine was accurate (the castings are generally good), although a quick flattening on the diamond plate of the undersurface of the body (the area with the three grooves giving location/bevel angle options the roller assembly) killed off a small amount of slop. (see the narrow bright strips in photo 2) This slop was probably caused by a minor casting imperfection, or maybe excess paint preventing the joint seating properly.

    I took it a step further which is optional and to taste - and may be overkill. Done this way it grips like mad with only moderate tightening of the clamp though!

    Cautious that the aluminium surfaces might in time mar i filled the depressions in the clamp faces with heat cured 5 min epoxy (140deg F for 4 hrs - max temp, only after initial hardening and don't exceed - gives a full cure and nice hard material that cuts well - pare it back with a sharp chisel and finish on the diamond plate - photo 3) and cut a pair of grippy stainless steel facing plates for them (photos 4,5) from a couple of old and purposely fine grit 'diamond dusted' steel chiropody nail files.
    http://tiny.cc/0cd7ix

    The ones i got felt like roughly P400 wet/dry paper. The epoxy ensures the (thin) plates are fully supported and bearing on a flat surface - they would otherwise probably crease when the clamp is done up. They were secured (to enable replacement if needed - heat to release - but silicone would do it too) with double sided tape.
    The gripping faces of the diamond files can be rubbed against each other to reduce the 'toothiness' of the grit to taste - left as stock they might slightly mark a highly finished chisel...

    The files can (just) be filed to a line when clamped between wood blocks (like when filing the edge of a scraper - photo 4), and the ends rounded on a disc sander. Take care when drilling to keep the rpm down and feed steadily a bit at a time with a toolroom quality HSS or cobalt drill, and use some lubricant and a steel support - stainless steel is tough and one of the files was quite hard. If it's let get hot it'll harden on cooling and won't drill...

    Hope this may help a few frustrated with what is conceptually and in most other respects a very nice tool.....

    ian


    veritas hg problem japanese chisel 17-7-14.jpgveritas hg flattening of castings 17-7-14.jpgveritas hg epoxy cut back 17-7-14.jpgveritas hg diamond nail file 17-1-14.jpgveritas hg clamp facings 17-7-14.jpg
    Last edited by ian maybury; 07-19-2014 at 6:48 AM. Reason: clarity

  2. #2
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    Hi Ian

    First of all, my apology for not (yet) replying to your email. Sometimes I have to wait to the weekend to catch up on my mail.

    Lots of good ideas here - I must pull my guide apart and check the surfaces out. I've had mine since pre-production and, with the exception of replacing a cambered wheel (my fault for not checking it was rolling free before use), I have experienced very few difficulties. Where there were, these were due to chisel backs being rounded. Your fix may sort out these as well. Well done.

    Regards from Perth

    Derek

  3. #3
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    No prob Derek, I had a head of steam up anyway. To be fair to Veritas it seems likely that most guides with clamp type blade holders may struggle with certain shapes of chisel back. Plus it's the sort of scene where minor difference can count for a lot. Even stuff like a trace of oil on the chisels.

    Time will tell how the mod holds up - just heading into a major chisel set up session now as so far i'd been using just a few from a set and sharpening fairly approximately.

    If the diamond dusted stainless steel (fancy heh! ) clamp facings don't work out there's scope to play with different materials. Another that might work (if it can handle the high pressures that will result from clamping over the angled back of e.g. a Japanese dovetail chisel) is something like the fairly thin sheet that fibre washers are cut from - again held on with double sided tape. (doing the clamp up tight for a few hours before use means that the tape gets a really solid grip) I'm not sure, but a trip to a good gasket supply house might thow up some options too: e.g. http://www.customgasketmfg.com/gasket_material
    Last edited by ian maybury; 07-19-2014 at 7:59 AM.

  4. #4
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    Good Job !
    Thanks for titling your photo of the nail file; that helped me keep what I was looking at straight in my head.

    For what it is worth the jig is made from and I quote the catalog “Manufactured from die-cast zinc alloy”. Maybe that is aluminum with zinc in it or vicy, versy. Doesn’t matter I guess.
    I just happened to see that the other day.

    Very informative about releasing the double backed tape with heat.

    A couple other things to say or thoughts :
    Do you guys oil the roller on the jig ? I am a feared of wearing mine out with all the “over sharpening” I do. My first generation Veritas jig was getting a little (or a lot) sloppy in the roller so I oil my Mk II. I recommend a drop of light machine oil from time to time.

    Another thing that came to mind, and I haven’t taken the time to see if they would be of any real use yet, but these concave / convex washers might be a useful mod for adapting the clamp plate to a tapered blade. They allow angle (toe) adjustment on some bicycle brake pads. Bike shops throw them away with the old pads so should be plentiful and cheep to acquire.

    bicycle brake pad concave convex washers

    That and or I was picturing a beveled plate to put in the jig when a tapered blade is to be clamped effectively making the clamping force perpendicular to the blade back.
    Different tapers you say. Yah . . . I know . . . that is where the set screws come in to fine tune the wedge angle. What set screws ? Oh. . . well . . . I haven’t invented that yet.
    Just “brain storming”. Or in my case “brisk breezing with a bit of misty showers and fog”.

    and or a floating jaw
    See examples here
    vise jaws for clamping tapered work
    Last edited by Winton Applegate; 07-19-2014 at 10:22 PM.
    Sharpening is Facetating.
    Good enough is good enough
    But
    Better is Better.

  5. #5
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    Ta Winton, time will tell how well it works out. Needs must as i saw it. I took the castings to be aluminium, but it's more than likely that they actually are zinc. (it's commonly used to cast intricate parts like carburettor bodies and the like) It would make sense, in that the clamp without the steel nail file facings was soft enough to mark under pressure from the hand knobs acting on the raised edge on the back of a Japanese dovetail chisel. (you can see the line in the photos)

    My guide is only coming into use now, but oiling the roller has to help big time - a plain bearing running in the presence of water borne grit and the like must need some care. I've seen a machine struggle with seizures in a similar situation. With luck the oil stops the grit from working its way into the gap. Is yours working out OK? My recollection is that the roller assembly can be bought separately, so presuming reasonable life wearing out shouldn't be the end of the world...

    It's the studs through the holes that actually locate the clamp facings, the double sided tape has only got to stop them flopping about and getting in the way when loading the tool. (the photo of them in situ didn't download for some reason, but it's below now)

    Options to improve the clamp may depend a bit on the shape of what it's to be used to hold - but the stock floating bar (with studs in) works across a fairly wide range of situations. Almost any universal arrangement will be better at some shapes of blade than others. The basic as i saw it was that while the clamping force could be applied in various ways, it's the other half of the clamp (the fixed/body surface that contacts the accurately flattened back of a blade over quite a large area) that is the more critical/does the heavy lifting so far as holding the blade in place is concerned. In that it needs to be both flat (to maintain tool alignment, and maximise gripping area) and grippy enough to provide the friction needed for rock solid fixing without without too much tightening/with moderate clamping forces. One limitation when considering clamp mods is that there's not much vertical room to spare...

    veritas hg facings in position 17-7-14.jpg
    Last edited by ian maybury; 07-20-2014 at 9:31 AM. Reason: clarity

  6. #6
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    Ta Winton
    is that like Ta Wanda ?
    ha, ha,

    Yah mine shows a fair amount of wear but still works fine (I use the cambered barrel shaped roller anyway). It means the angle setting is less accurate now if it ever really was close in the first place. It is all relative anyway. As long as I can get back in the ball park when I need to 4 or 5 degrees off isn’t a disaster.

    As I recall, when I first looked at the roller wear "problem" I figured when it got bad I would bore out the roller on the lathe and put in some small sealed cartridge bearings.
    Not these exact ones. I work with them quite a lot so no big deal.
    Sharpening is Facetating.
    Good enough is good enough
    But
    Better is Better.

  7. #7
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    Not sure what 'Ta Wanda' might be from either Winton. Being on the other side of the Atlantic i don't speak American very well. 'Ta' over here is a short/slang form of 'thanks' - no overtones….

    PS just finished the first couple of (Japanese white steel with a single bevel) chisels with the modified Veritas guide. (using Shapton professionals) No problems whatsoever, it's very comfortable to use. No problem with the diamond facings marking the polished backs either. The opening to the rear of the guide means it's very easy to hold - your thumbs fit in so that the chisel ends up being held very much up at the bevel end - almost as though hand sharpening...
    Last edited by ian maybury; 07-21-2014 at 8:21 AM.

  8. #8
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    The sort of tool that might be useful for keeping the roller oiled on a Mk2 honing guide without getting oil where it'll cause problems (camelia oil might be a good choice) - don't know anything about the quality though. There's other similar options about: http://www.ebay.com/itm/Precision-Po...item2578f769c0

  9. #9
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    How did you press the studs out of the clamp bar? I'm getting nowhere trying to do that. As an aside my clamp bar looks like a banana. I ordered two more of them from Lee Valley as a special order.

  10. #10
    Quote Originally Posted by ian maybury View Post
    Not sure what 'Ta Wanda' might be from either Winton. .
    No worries, Ian. Nobody over here knows what it means, either!

  11. #11
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    Hi Ralph. Sorry, but I missed your post when you put it up.

    My studs came out pretty easily, but maybe there's some variation between examples. Either way the clamp bar is probably zinc, and is marginal for the job it's doing - it's possible to bend it even doing the clamp up by hand. Steel might have been a better idea.

    The key to getting the studs out without causing damage is to support the clamp bar in the area around the head of the stud you are pressing out. Best not to try to hammer it either.

    The stud is a proprietary item of a sort i saw offered years ago by Southco - it has a simple disc like or flanged head, but with splines/serrations cut in its perimeter. (like miniature gear teeth) The idea is that when it's pressed into place in a cylindrical countersink of a diameter a bit less than the head the splines cut into it and get a grip.

    I got mine out by starting with a block of birch ply (hardwood would be fine) about 1/2 in deeper than the length if the stud, and drilling a hole through a bit larger than the diameter of the head of the stud - for the stud to move into. I then chiseled a nest in the ply in the area around the hole for the head side of the clamp casting to fit into. (it's an odd shape) Then placed it with the clamp in the nest (and the head of the stud over the hole) in an engineer's (iron) vise and pressed the stud out - as the stud moved out it entered the hole in the ply block. Once the head comes free the threaded part of the stud is a clearance fit in the clamp bar.

    Thinking at first that it was possibly a shrink fit I had previously heated the clamp a bit (to maybe 140 deg C?) in the hope it would drop out. It didn't - but it might (or might not) have made it easier to subsequently press out if a retaining adhesive was used. If you decide to try heat don't overdo it - if as is likely it's zinc the melting point is only about 420 deg C, and you would rather not burn the coating off either.

    Reassembly is easier - drill two vertical holes in a rectangular block of ply or hardwood spaced to match the clamp studs and secure the block firmly in a vise. Place tiny amount of high strength threadlocker on the serrations on the head of each stud (use the end of a paper clip or something like that, keep it well clear of the threads), drop the studs into place, rotate the heads so the serrations engage with those already in the clamp, lower the assembly so the studs enter the holes in the ply block, and so that the flat face of the clamp rests on and is fully supported by the face of the ply. A couple of good firm taps with a hammer and a a bit of flat ended steel rod a shade smaller in diameter than the heads will seat the studs - it again doesn't take a lot of force.

    ian
    Last edited by ian maybury; 07-30-2014 at 5:47 AM.

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