Saving some electrons

So I got a little motivated reading Schwarz – it sounds so easy, all this hand planing etc.

Got out the hand planes, and my DMT diamond whetstones, and sharpened my plane irons.  I used the camber roller on the Veritas Mk II to produce a slightly rounded front edge (according to Chris, this is good for Jack Planes for heavy stock removal).

DMT Diamond Stones

From left to right, the plates are the Extra-extra coarse, the extra coarse/coarse (double sided), the fine/extra fine (double sided) and the Extra-extra fine DMT whetstones.

The extra-extra coarse is a ripper – the rate of metal removal is impressive, and it takes next to no time to get the blade to the shape you want, even when it has been used for other purposes (opening paintcans is a pretty typical activity for an abused chisel!)

The extra-extra fine gives that mirror finish.  The other four grades allow you to work through each, as is good sharpening practice.  As much as I don’t mind the double-sided concept, I would really prefer to have each grade the same physical size as the larger two I have, and ideally single sided.  The cost is really in the diamonds, not the base material.

The larger size is ideal for something like the Veritas Honing Jig, especially with the larger plane blades I sharpen.

The other secret about diamond plates is they actually get better with use.  Yeah, weird, but it is a fact never the less.  DMT plates have very consistent diamond size – nothing like a rogue diamond to scratch the hell out of your otherwise finished blade edge, so a quality plate avoids that danger.

Camber Roller

You can’t see it in this photo (didn’t have the right lens with me) but there is now a very mild camber to this blade, stopping the corners from digging in while ripping off massive amounts of the surface of the timber.

I needed to clamp up the piece of Camphor Laurel I had chosen for the exercise, and needed some more dog holes.  While marking these up, I discovered just how warped the surface of my workbench was.  That might explain a few things I’d been experiencing.  Not sure what I will do about it (if anything).  Problem will be solved by making my own workbench (one day).

I chose the Camphor Laurel as it had been resawn with the chainsaw jig on the Torque Workcentre, and had quite significant ridging – a perfect candidate for a Jack Plane.

Ridging

Ignoring the step (this being the other side of the board fwiw), these were the ridges I wanted to see disappear.

Started off with the Jack Plane, and really couldn’t get anything happening.  Just isn’t right – something not working.  Then I remembered reading something in the Anarchist’s Tool Chest about Chris talking about using the Jack Plane across grain – the fibres being weaker in that direction.  Sure enough, that worked a treat, and great swaths of timber came flying off.

Shavings

From there, I moved onto the trying plane to create a flat surface.  With the long bed, it rides on top of the ridges so they get cut down until such time as you get full-length shavings. (These were performed with the grain, rather than across)

It was about this point that I was really discovering that hand tools are:

1. lubricated with perspiration (it is quite labour-intensive!)

2. more involved that you’d expect – a powered tool that takes 1000 cuts/minute (or more correctly 16000 – 40000 (2 flutes on a router bit running at 20000 RPM) is quite different to a blade skimming along the surface at a fixed attack angle.  You can get away (easily) with a (comparatively) blunt blade on a powered tool, whereas a hand tool needs to be razor-sharp.  Imagine how impressive a powered tool would be with the sharpness of a handtool.  Required motor power would be so much less, finish significantly high.

3.  slow, and take a lot of physical effort.  And quiet.  Power tools are noisy, and produce a lot of wood dust along with fine wood shavings (the result of thousands of tiny cuts, rather than one long cut).

Smoothing cuts

Then moved onto the smoothing plane.  This is quite a bit shorter, and is designed to take fine shaving cuts, leaving a smooth finish.  When properly tuned, the finish can be shiny, providing a mirror finish.

So I got a semblance of a result.  A bit too scalloped out of the middle – must have concentrated a bit much effort there.  Not sure whether it was harder than expected, but it does go to show that even if you are very proficient with powered tools, that knowledge does not readily transfer.  Gives one a real respect for those who live with handtools (or had no choice through the ages).

Need another woodshow so I can pick Terry Gordon’s brain about the basics again!  Using handtools to prepare a board – one of the new show demos for TWWWS 2013!  I’d sit in for that 🙂

Diamonds are a Tool’s Best Friend

Diamonds.

Pure carbon, but not something that is going to upset the greenies, or the skeptics.

The hardest natural element known, it can only be scratched by other diamonds (a simplification, but good enough for our application).  It is not the toughest substance known – good compared to other gemstones, but not as good compared to many engineering materials.  However, it is this hardness that we are particularly interested in for tools – when sharpening, you are scratching the surface (which is where diamonds excel) with increasing finer grades, until a mirror polish is achieved.  If a diamond does fracture, it reveals another facet, and continues to do what it does best.

A diamond whetstone then is a powerful sharpening tool in the workshop.  Unlike other sharpening surfaces, a diamond whetstone actually gets better with use.  Cool huh!

DMT are my preferred diamond product company – they have some innovative products, and use a serious manufacturing process which binds a quality diamond in a high concentration, with a very consistent diamond size – important in sharpening situations (you don’t want deep random scratches from a rogue diamond).

Interestingly, it seems they have not continued with their fine ceramic stone – that always confused me from a diamond specialist company. (Or perhaps it just wasn’t listed on the handout included with my latest shop addition)

So their line up of grades is now:

Extra-extra coarse 120 micron

Extra coarse 60 micron

Coarse 45 micron

Fine 25 micron

Extra fine 9 micron

Extra-extra fine 3 micron

From there, you get into the pastes (and not something I’ve tried), which comes in a 6 micron, 3 micron and 1 micron grade.

They have DiaSharp stones, folding whetstones (plastic covers), Wavy plates (used to match the internal and external radius of curved tools, such as gouges, and the Aligner for kitchen and pocket knives (including serrated blades).

Not everyone wants to use diamond for sharpening, and that is a perfectly acceptable perspective.  I personally like the very soft, yielding surface of the japanese waterstone.  Others are fans of oil stones, or Arkansas stones, or ceramics.  All of these will wear unevenly because of what they are made from, and to get the sharpest surface, you need a flat sharpening surface.

You might use the sandpaper technique – a piece mounted on a sheet of plate glass to produce a flat surface and rub the stone on that.  Or another technique is to rub two stones together.  But there is another solution, and it will be of no surprise, it is a DMT diamond solution.

The latest product from DMT is the Dia-Flat Lapping Plate.  Each plate is hand checked and certified as being flat to +/- 0.0005″ (+/- 0.01mm).  It is the same as an extra-extra coarse stone, but with extra focus on its flatness, and a stripped back to fundamental design to come up with a bonding process to ensure the stone is durable enough to cope with the torture of flattening other stones (oil and water stones).  That inflicts some serious punishment, and this is a stone that laps that sort of punishment up (yeah, a very intended pun!)

At 10″ x 4″, it is an uncompromising size – taking your entire favourite whetstone, and flattening the entire surface in one go.

Check out this video by Stan Watson, the Technical Director for DMT on using the Dia-Flat to flatten a waterstone.

Mine will be subjected to the ultimate flattening process shortly (most likely over the coming weekend)  No more hollow sharpening stones for me!

 

Diamond Knife Sharpening

With Christmas approaching, you can pick up a Tormek at quite a good price at the moment, particularly care of parity of the Australian and US dollars.  Latest price I’ve seen is $899 for the T7 from Carbatec, and $599 for the T3.  That will obviously produce exceptional edges on all your sharp tools (with the right jigs), but for small knives I’ve also come across this product from DMT (which also has an excellent name in their chosen field) which is surprisingly (or not such a surprise given it is DMT) effective.

Deluxe Aligner Sharpening Kit

The Deluxe Aligner (strange name) has a knife holder, guide bar, stone holder and 3 DMT diamond stones (45 micron, 25 micron, 9 micron).  It also has a round file for serrated blades and a storage bag.

Sharpening Edges

When you first see it/set it up, its plastic feel and seemingly loose tolerances don’t fill you with the confidence that it can do the job, but I was again surprised how effective it was, particularly on a small blade like my Leatherman, and small kitchen knives (4″ & 6″).  The knife is secure, and using the height adjustment you set the angle for the grind/hone.  It is double sided so you can flip it over to do the other side as well.  After working with the first stone, it is easily changed out without affecting the settings so you can work through the three stone grades.

Sharpening Serrated Edges

For once, serrated edges are not forgotten either, and a tapered (cone) sharpener is provided which uses the same guide to achieve the repeated and repeatable angle to sharpen inside the serrations.  Again very beneficial for my Leatherman which has both a straight blade and a serrated one.

So an excellent little sharpening jig – useful for kitchens and sheds alike.  Available from Maxis Tools (and presumably therefore Carbatec, either now or in the near future)

Fighting the Mess Gremlins

Now approaching 2 years since the shed upgrade, and I’m still dealing with some of the after effects.  But I’m getting there slowly.

Was out at the shed last night to almost 3am, watching episodes of “The Wire” on the TV, and going through boxes of stuff that hadn’t been unpacked since the crazy hazy days of the deliberate shed implosion.

Storage

It won’t mean too much to you – the boxes here don’t look all that different from other times they’ve been seen, but this time there is a lot more organisation than chaos represented.

From left to right, top to bottom, there are the sharpening items – Alisam sled, DMT stones, Japanese waterstones.  (I still have another article on diamond stones to do, but and still hanging out for the Extra-Extra coarse DMT stone that was sent over 6 months ago by DMT for me to include, but unfortunately didn’t quite manage to arrive….yet).  (Every shelf tells a story, but if I told them all, we’d never get to the bottom!)

Under the Japanese Waterstones is the granite reference slab.  To the right is the Kreg Pockethole stuff (clamps, bits etc)
The next shelf are liquids, saws (still homeless), T&T sanders
3rd shelf – rags, safety gear,chaos and tapes
4th shelf – chaos, chaos, sand papers (sheet and roll) and steel wool

So obviously lots still to do.  Looking at sheds that really have it all together, and I can’t begin to imagine how many hours, weeks, even years of work have gone into creating the havens they are.

While in a clean-up phase of mind, I also had a look at my sharpening jigs, and decided to wall-mount them.  The T7 came with the wall mount for the original jigs, and given I still have the boxes the other jigs came in that were designed to be hung, thought that might be as good a way as any to continue to display them for ready access.

Tormek Jigs

I might have to chase up with Promac to see if any of the other wall mount blocks are available separately – they seem a good way to store, and make available the various jigs.  I still have a few Scheppach jigs there as well that I hope to upgrade over time to what I’d regard as the superior Tormek jigs.  Even the basic square edge jig demonstrates the difference – one is folded metal, the other cast.  One can easily cause a chisel to skew while sharpening, the other has well-planned reference planes.  Your experiences may vary of course.  I have achieved mirror polish finishes before with the Scheppach/Triton, but the Tormek…well…

Below my jig wall, I’ve taken a spare support arm I had from the Triton/Scheppach sharpener and drilled a couple of holes for it.  It is there because some of the jigs don’t fit back into their original box when assembled, so I thought they could be stored on this arm instead.  I have done the same for the Scheppach planer blade sharpening jig, if only to store it.  As someone pointed out, it doesn’t fit the Tormek because there is a different distance between centres of the support arm.

With the right jig, these machines can sharpen most tools in the shop.

Woodworking on Holiday

I’ve actually been down at Phillip Island the past 4 days, having a bit of a family holiday (seeing the penguins etc). Did you miss me? 😉

A while back I was interviewed by Tool Crib, and one of the questions was:

If you could only have 5 tools for all your woodworking for one year what would they be?
Dovetail Saw
HNT Gordon smoothing plane
good set of chisels
Colen Clenton Square
Chris Vesper Marking Knife

Hope that would be enough to really get to the roots of woodworking again. (And if I could add one more, the Triton Superjaws so I could clamp the pieces as I work!)

Well I’m not sure if that influenced me or not, but for this trip away I decided that for some of my downtime I was going to do a bit of woodwork, so what I took along for the ride was:

Rockwell JawHorse
Set of Hamlet Chisels
Veritas Dovetail Saw
Veritas Dovetail Markers
Chris Vesper Marking Knife
DMT Diamond Stones (Ex Coarse through to Ex Ex Fine)
Alisam Sharpening Sled
and Tasmanian Oak from Misan Timbers & Craftwood

Didn’t get a lot of time to play, but did get to spend some time one day on a large sharpening session, getting the various chisels up to a decent working condition.  It also gave me a chance to break the DMT Diamond stones in – they apparently work better after some use (and I observed that as well)

The set I have runs from Extra Coarse, Coarse, Fine, Extra Fine and Extra Extra Fine (there is also an Extra Extra Coarse stone on its way, but it has had a slight….uh….delay).  The diamond stones are an impressive way of sharpening.  I have used a number of different methods and they all have advantages and disadvantages, including scary sharp (sandpaper), waterstones and slow speed watercooled grinding wheel.

Photographic Evidence

Photographic Evidence

The DMT Diamond Stones are flat, and unlike waterstones remain flat irrespective of grinding technique.  They cut extremely well – unlike sandpaper they continue cutting as long as you need, without the sandpaper wearing out.  It was quite surprising using the finest 2 stones, particularly the extra extra fine (8000 grit) – to look at it you can hardly pick which side has diamonds and which doesn’t – they are that fine.  So it was quite impressive seeing the river of black that was generated – the finest particles being removed from the surface of the chisel leaving a near mirror finish.  In time, when the stone is broken in properly, it would not be surprising to get a fully mirrored finish off this stone – quite impressive.

The next day I got another window to play, so tried again at a handcut dovetail. The pins went reasonably well – better than last time at least, but the tails were still a bit ordinary  – getting the outline of the pins transferred accurately, so the tails are the right size is still eluding me.  However the resulting joint, as ugly as it is, is still better than the first – the joint went together after some fine-tuning, and as tight as anything.  An improvement, and as much as it is interesting handcutting the dovetails, it is still frustratingly slow compared to router methods (which also look so much neater, at least when I do them and compare to my handcut methods!)

I’ll keep trying, but I’m still finding it hard to justify the time involved!

Riding the Wave

Looking like a model for a proposed youth skateboard park, the new DMT Diamond Wave was released about a month or so ago, and has since surfed its way down under to Stu’s Shed.

DMT Diamond Wave

DMT Diamond Wave

Comes in both a Fine and Extra Fine version (a 600 grit/25 micron diamond and a 1200 grit/9 micron diamond) (but still, divide by 3 to get the exposed diamond size!)

At 10″ long, and a continuously changing diameter surface at some point many gouges etc will get a match. I can almost imagine one mounted to the side of the lathe, and as you are turning, you can take a couple of swipes on either side to get a perfect edge.

Obviously perfect for carving chisels (and perhaps more suited – wood turners (real ones as opposed to my pretending) use a couple of quick wipes on a fast spinning AlOx wheel)

However, I may not be much of a wood tuner, but I see the future, and it contains amazingly sharp turning chisels and gouges. I might turn poorly, and take ages to produce something, but you’ll be able to shave with my tools (and check out your reflection in the edge of the next!)

Q&A with Stan Watson – Technical Director, DMT

I was recently contacted by Stan in response to some articles here that have been referring to DMT Diamond Whetstones, and he kindly offered to field any questions I might have.  Unfortunately I certainly did have some that I was very pleased to be able to put to a real expert in the field, and Stan has agreed to allow me to republish them here. (I have taken the liberty of adjusting the questions and responses a tiny amount (like using the Ex Ex Fine stone!) to fit this format, and open forum).  I found the answers quite fascinating, and they will take a bit to really assimilate them properly into my expanding understanding of sharpening processes.

So to the Q&A with Stan A Watson, Technical Director, Diamond Machining Technology. www.dmtsharp.com

Stu’s Shed:

Sharpening is obviously one of those topics that deserves a decent amount of coverage, which is how diamond stone sharpening became a topic.

In the first instance, I was wondering if I was indeed on the right track when comparing different sharpening media by converting all the different grading systems used to that of the actual abrasive particle size in microns, and if my hypothesis is then correct that you can step from one form to another and back again, so long as you are progressively moving from a larger abrasive to a smaller one?  In saying that, I understand that some abrasives work by breaking down and continuing to abrade as they get smaller so they cover a range of sizes, but the majority are treated as consistent in size from new to exhausted.

Stan A. Watson:

Abrasive particle sizing is at best a huge mix of systems. The single best way of comparing abrasive to abrasive is the micron system which is an actual measure of grain size in absolute terms. The other systems in use today; CAMI / UAMA (Coated Abrasives Manufacturers Institute / Unified Abrasives Manufacturers Institute) FEPA (Federation of European Producers of Abrasives) USS (United States Standard Sieve) JIS (Japanese International Standards) and “grit size” are all arbitrary size designations with no relevance to any true physical dimensional scale. As far as abrasives breaking down during use, you have touched on the vast difference between the action of loose and bonded abrasives and that abrasive which remains solid or which tends to be more friable during use. A loose rolling abrasive sharpening system (lapping, SiC paper and waterstones) tend to produce much different results that a true fixed bonded system such as DMT Diamond Whetstones.

Stu’s Shed:

With that in mind, does the measure of particle size of diamond abrasives fixed to a medium (where only a portion of the particle is actually exposed above the surface) compare with those where the particles are free to move (such as in diamond paste)?  I note from your website that only 1/3 of the diamond is exposed, so is the particle size the site provides the size of the actual diamond, or the size of the exposed portion of the diamond?  (In other words, when I have stated the Ex Fine DMT stone particle size is 9 microns, does it actually perform as one with a particle size of 3 microns)?

Stan A. Watson:

We designate the actual size of the diamond itself so for instance when we state that the Fine / 600 mesh / red / 25 micron grade of diamond, we are actually using a 25 micron size diamond where only about 8 to 9 microns is exposed above the metal bond. That being said, let me state that there is a size range about the mean particle size or a Gaussian distribution of particle sizes which would be from about 23 to 28 micron. But, rest assured that DMT takes advantage of a highly sophisticated system of fluidized bed micronized particle separation to ensure there are no oversized / undersized rogue diamond crystals in each diamond grade.

(Editor’s note: This feature cannot necessarily be said about all diamond stone manufacturers products, this technique ensures a dependable crystal size for DMT stones, but your mileage may vary with other manufacturers, and this can be assessed in part by observing the performance and surface finish obtained when using other manufacturer’s diamond stone products. The problem with a rogue stone in the matrix is it will cause gouge marks in the material being ground that will cause significant amount of additional work with the next stone grade to remove, if that is even possible.)

Stu’s Shed:

By looking at the particle sizes of the 4 sides of the DiaSharp stones I have, there seems to be a large step from the fine to the extra fine stone, and if I was dealing with silicon carbide sandpaper for example, I would use a few more grades in between before jumping to the extra fine particle size.  Is this actually valid, or have I headed off on a bit of a tangent there?  I would expect that DMT wouldn’t put out ‘fine’ and ‘extra fine’ grades without intermediate stones if you couldn’t go from one to the other, but it does seem quite a step.

Stan A. Watson:

The actual step from “Fine” to “Extra Fine” is from a 25 micron to a 9 micron (8-9 micron  to 3 micron exposure) and progresses nicely in the range of micron sizes we offer. You can control the surface finish quite nicely by controlling the applied force during sharpening so as to finish up each step in the progression of sharpening with lighter and lighter strokes. The comparison with diamond to SiC paper is not really an apples to apples comparison as the SiC paper while being a bonded abrasive is friable, looses the particle bond quite easily and could be of either “open coat” or “closed coat” type.

(Editor’s Note: There are two common patterns used when bonding the abrasive to the backing material, called “Open Coat” or “Closed Coat”.

An Open Coat pattern is when there is a lower density of abrasive particles, so the entire particle can dig deeply into the work, facilitating faster material removal, and less likelihood of waste particles clogging the abrasive material.  The particle size in this case – the working size of the particle as it were, is closer to the actual measured size of the particle.

A Closed Coat pattern is when the particles are tightly packed together on the backing material – a denser pattern. With the gap between particles being very small, the abrasive cannot bite in as deeply, resulting in a finer finish (or being realistic about what we are talking about here – a finer scratch pattern), and the effective size of the abrasive particles is much smaller than the actual particles themselves.  These materials tend to need some form of lubrication because of the increased heat buildup.)

Stu’s Shed:

In the article on the Alisam sled, one assumption I have made is the consistency of thickness of the DiaSharp stone (and in particular that the two sides are parallel).  Do you have a listed tolerance for the thickness, or should the stones be mounted in an adjustable holder to ensure the top surface is parallel with the base?  The Alisam sled obviously assumes the sharpening material is parallel with the surface their sled runs on.  I was reluctant to use the diamond stone on my precision granite block, because being double sided, I would expect the diamonds on the underside to cause some damage to the comparatively softer block.

Stan A. Watson:

The DiaSharp product is produced to a parallel,  thickness and flatness tolerance and you should be confident in your ability to step from stone to stone with out having to adjust the iron in the Alisam jig.  Yes the diamond on the bottom of the double sided stones would adversely affect your granite surface plate.

Stu’s Shed:

I am planning on doing a video feature on diamond sharpening (as I have with slow speed grinders, and will for Japanese waterstones and “Scary Sharp”). Do you have any particular advice about the use of these stones that are at the extreme ends of the diamond whetstone scale – the XX Fine and XX Coarse DMT Stones?

Stan A. Watson:

Remember that especially with the performance of the XX Fine there is a break in period and the stone will produce better and better results the more it is used. Also if you are using the XX Coarse to flatten waterstones, do so under running water to flush out the abrasive slurry as quickly as possible.

Stu’s Shed:

Sorry about the long list of questions – writing these articles often raises as many questions as they answer!

Stan A. Watson:

No problem, I am more that happy to correspond with you about anything that I may be able to contribute to.
Best Regard! Stan.

So a big thank you to Stan Watson for not only obliging me with very comprehensive answers to my questions, but also for allowing those responses to be published here.  There will be a video in the near future demonstrating the use of the DMT Diamond Whetstones in action, so keep an eye out for that in Stu’s Shed TV / iTunes.

True Grit

Being inspired by the recent look at diamond stone sharpening, (which is a topic I have returned to on a few occasions already, covering the different aspects of sharpening), I have again raised a few questions I have wanted to answer, and the more answers, the more questions I find to ask!

One thing that seems to be a regular stumbling block is the issue of the grade of the abrasive material.  So many seem to use a similar system of depicting the abrasive properties of the material in question, but then things seem to not quite line up.

Is a 1000 grade waterstone the same as P1000 (ISO system) sandpaper?  And is that the same as 1000 mesh diamond stone?  Or 1000 grit sandpaper using the CAMI grading system? Sort of, no, no, and that is just the start of the confusion.

Without getting into actual definitions, an abrasive is typically small particles that are harder than the substance you want to abrade.  How they are presented to the item is more a matter of choice than if one system is better than another.  They could be a powder which has some oil added and use on top of a flat surface.  Or in a wax and added to a felt wheel.  They could be secured firmly in a permanent base (although only diamond really justifies this).  They could be in a soft matrix and formed into a flat slab, or turned into a slow spinning wheel, and so on.

I’m still not unconvinced (yeah, double negatives) that I’m on the right track by breaking down all the different systems to their micron equivalent.  So perhaps all abrasive systems should be sold using that designation.  Pick up some 100 micron lapping paste to get a flat side, switch over to 75 then 50 micron sandpaper, then use the 35 then 25, then 20 micron diamond whetstones, really develop a mirror with 15 and 10  waterstones, and finally a 5, 2 and 1 micron diamond paste for a deadly edge.  Wonder if I can market that concept?

Oh, and if you wondered what a 3 micron diamond abrasive can do (which is roughly equivalent to a 1 micron friable product) , have a look at the mirror surface of this chisel, sharpened on the DMT “Steel Waterstone”, which is their finest diamond whetstone (also known as the Ex Ex Fine). That’s an awesome finish!  I’m building a list of items that cannot be purchased in Australia that I’d be rather keen to get to try.  This stone is one of them (as is the Forrest Woodworker2 sawblade).

DMT Steel Waterstone

DMT Steel Waterstone

You just don’t realise how big this topic is until you start really delving into it.  Like every topic in woodworking really.

If you are looking for a bible on the subject, start with Lie-Nielsen’s take on the subject from Taunton Press.

nielsenThe guy who comes up with handplanes like this definitely knows his way around the idea of sharpening an edge!

nielsenplane

In the light of this article, I decided to do a quick audit of what sharpening gear I have, and therefore what is still missing from a good system. And because of my push above, I’ll list them in micron order!

Micron Description Speed
269 A60 Grinder 3600RPM
162 Norton Al Oxide 100 3600RPM
68 Triton WetStone 120RPM
20* DMT Ex Coarse Diamond Hand
15* DMT Coarse Diamond Hand
14 Japanese 1000 Waterstone Hand
8* DMT Fine Diamond Hand
3* DMT Ex Fine Diamond Hand
3 Tormek Honing Compound 120RPM
2 Japanese 6000 Waterstone Hand

*I have amended this list in light of recent discussions with the Technical Director for DMT, and the micron size now listed is based on the size of the exposed diamond, which is what is doing the cutting and not the size of the diamond in total (2/3 of which is buried in the Nickle plating).

Not listing sandpaper of course, although it would be valid to include them.  The finest sandpaper I have is P2500, which is around 8 microns.

I also have a Granite Plate, the Alisam and Veritas Mk2 Honing Jig, a bench grinder and the Triton Wetstone Sharpener.

I wouldn’t mind having a diamond whetstone around 15 micron to fill that gap, and around a 2000 waterstone to narrow the jump from 1000 to 6000.

Alisam Sharpening Sled and Diamond Stones

There are two main aspects of sharpening edge tools.  One is the abrasive, and the other is presenting the tool at a consistent angle to that abrasive.  The more accurately this angle is maintained, the better the result, and the easier the entire sharpening process.  Jigs that assists you in maintaining that angle are known as sleds, or honing guides.

I’ve spoken in the past about the Veritas Mark 2 sled, which runs on top of the sharpening medium.  This sled from Alisam takes a different approach, and runs on a smooth reference surface which the stone is also on.

This concept does not work for waterstones, which although flat can have any amount of tapering, rendering the sled ineffective.  However, it is ideal for diamond stones, where the thickness is very uniform, the Scary Sharp method (using sandpaper), or using powdered abrasives / lapping powders. The guide is therefore not required to travel on or through the abrasive.  I haven’t tried it, but you could imagine the potential damage to the brass wheel of the Veritas if used on the Ex Ex Coarse DMT Diamond stone (which is around the equivalent to ISO120 sandpaper), or having to push over and through lapping powder.

Diamond Stones and the Alisam Sled

Diamond Stones and the Alisam Sled

I have chosen the SS3 Alisam Sled from Professional Woodworkers Supplies here, as it is the lowest of the three, and ideal for the diamond stones I am using. There is the sled (obviously the blue thing!), the 2 DMT Diamond Stones, and an HNT Gordon Plane blade (this is a reject one because it did not meet Terry’s standards, and so I can use and abuse it without feeling I am wasting good steel (the ultimate crime!)) You could just as easily substitute a normal plane blade, or a chisel etc into this guide. I am using a base of MDF, which is remarkably flat because of its manufacturing process.

Setting up for sharpening a plane blade

Setting up for sharpening a plane blade

The guide is set up with the blade roughly in place, before fully clamping down on it.  The black ring (to the right of the blade) is used to set the blade perpendicular to the guide.  Under the stone, you can see two dark tracks, which is where I was already working the blade before taking the photos – this is some of the metal removed from the blade, where it has been forced into the board by the jig.  It doesn’t affect the accuracy, and just shows how fine the particles are that get removed.  There will be little to no abrasive there because of the quality of the diamond stones.  Unlike a waterstone, the diamond stones are not designed to shed the abrasive as part of the sharpening process.

Setting the sharpening angle

Setting the sharpening angle

To set the grinding angle, one handle on the sled is loosened, and the drawn mark lined up with the required engraved angle.  This is not an eyechrometer thing though – underneath the side (as you may be able to make out), there are accurately machined indents which positively engage on raised areas of the jig body, so the angle is perfect, and perfectly repeatable.

Angle Set

Angle Set

Here I have set the angle to 30 degrees, the blade is clamped down (and I’ve moved the alignment ring out of the way, although this was not necessary).

Working through the grades

Working through the grades

You then run back and forward over the stone to grind the blade – one interesting point is in theory if you kept going you would find it cutting lighter and lighter until the blade could no longer reach the stone. This has been addressed very cleverly by having the front two wheels spring loaded – they have a tiny amount of vertical movement allowing more or less cutting pressure to be applied to the blade.  I was quite impressed when I discovered that.  The other beauty of this jig is you can use the entire stone, and not just a half or so, as the jig is not running on the surface at the same time.  I found it a very easy honing tool to use, and it cut quickly because of both the pressure I could choose to bring to bear, and that each stroke used the entire stone length.

Coplanar Guide Wheels and Blade

Coplanar Guide Wheels and Blade

From underneath, you can see the 4 rollers (the right-hand two, which are the forward rollers are the ones that are spring loaded).  The blade in this case is close to being complete.

Flattened Blade

Flattened Blade

This is about as far as I could get on the diamond stones I had.  My next step from here would be to move onto even higher grades of abrasive to really get a mirror finish (and obviously to flatten the back of the blade to the same condition – there is no point having one mirror surface if the back of the blade is pitted, rusty, chipped etc.)

Just a point too on the apparent loss of the hollow ground in the centre of this blade – remember this was a reject blade, and the slight warping made it scrap.  Even so, that is becoming a very well dressed edge, and it wouldn’t take much from here to bring it up to being fully live.

Diamond Sharpening

There are many different abrasive systems used to produce sharp edges on tools, be that sandpaper, abrasive grits, waterstones, oil stones, or diamond stones (among others).  They all have one thing in common, and that is very hard precisely sized particles suspended or retained in a soft matrix.

The quality of the hard particles goes a long way towards the quality of the abrasive.  Strange as it may seem at first glance, this even applies to diamond – there is diamond, and then there is diamond.  For example, the diamonds need to be bound securely into a parent material, if not they come loose, and not only are lost, but can really gouge the tool as well.  Also too, you can have a few diamonds, or a lot, evenly sized diamonds or not, and diamonds that are strong and durable, or ones that easily shatter and shear.

I have sourced some diamond stones from Professional Woodworkers Supplies which have a good name for quality and durability.  They are DMT Diasharp stones, and the ones I have chosen are double sided, so are the equivalent of 4 diamond stones.

For some reason, DMT only categorise their stones as fine, coarse, extra-coarse etc, which is rather frustrating when trying to compare apples with tomatoes. However, I have been able to determine what the equivalent is across all abrasive types, by finding out what the size of the abrasive particles are, which means it is easy to switch and swap between all the different abrasives and still be working “through the grits”. This earlier article of mine on comparing abrasive systems spells it out in a table form.

From the DMT website, I was able to determine the actual particle sizes:

Stone Mesh Micron Effective Micron
Ex Ex Coarse 120 120 40
Ex Coarse 220 60 20
Coarse 325 45 15
Fine 600 25 8
Ex Fine 1200 9 3
Ceramic 2200 7 ?
Ex Ex Fine 8000 3 1

*I have amended this list in light of recent discussions with the Technical Director for DMT, and the effective micron size now listed is based on the size of the exposed diamond, which is what is doing the cutting and not the size of the diamond in total (2/3 of which is buried in the Nickle plating).

Just out of interest, the concept of “Mesh” originates from a sorting method for determining the particular particle size, by passing it through a number of sieves (meshes), with increasing holes per inch (and therefore decreasing hole sizes) until the particle can go no further, so it’s size is known.

Oh, and fwiw, 1 micron = 0.001mm = 0.00004″

When flattening something (whether that be sharpening, or sanding), you start off with a particle size (or grit) which is coarse enough to remove the existing structures and scratches caused by the tooling.  Depending on how rough the surface is to start will determine what is the correct grit to start with, and you keep working till the original machining marks are replaced completely with the scratches from that original grit. You then move onto the next higher grit, and work to remove the scratches from that previous grit.  Rinse and repeat through all the grit sizes until the final finish quality is achieved.  As you work up the grits, less and less material needs to be removed.  One thing I find annoying, is the manufacturers rate their abrasives based on the average grit size.  The problem with that is although the average is all very well, if you have a few much larger particles, they will cause some individual serious scratches which will remain in the project unless you return to a heavier grit and start again.  The better quality the abrasive, the less of a problem there is.

Oh, and one other myth – rubbing two abrasives together to produce a finer grit is just that – a complete myth. Imagine the individual particles of abrasive as tiny chisels.  Do you get a better, sharper, finer chisel by ramming it into another?  No- all you get is a blunt, chipped or broken edge which renders the tool useless.  Same with abrasives.

So onto the sharpening with diamond.  Diamond chips are just another collection of micro chisels.  These are securely bound in a base of metal for the simple reason that because diamond is so durable, you want to keep the diamond particles around as long as possible.  If they are not worn out, why get rid of them?!

The two diamond stones I chose are double sided.  One has an extra coarse side and a coarse side, and the other stone has a fine and extra fine side.  The equivalent in ISO sandpaper is 240, 320, 600 and 2000.  Unfortunately, I feel this already demonstrates a problem, that too many intermediate grits are being skipped.  400, 800, 1200, 1500.  This may explain why when I was using these stones, I found the final result less than the perfection I was hoping for.  Not a fault of the stones themselves, but more may be needed to really perfect the finish.  The lower two were fine, and the jump from 320 to 600 not too extreme, but going from that to 2000 was too much.  However, once you understand micron sizes, it is easy to switch from one material to another.  In this case, I’d probably stop at the fine diamond stone, and switch over to the Japanese waterstones to finish the process. (1000, 2000 and 6000, or in grit sizes: 14, 7.5 and 2). (Update, I now have a better understanding of the grading of diamond stones from the Q&A with the Technical Director for DMT, which covered this point, and demonstrated that there is much less of a jump in the effective micron sizes than I realised)

Part 2 will document the stones in use.

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