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.

Flattening Waterstones

Been doing a little preparation for a video on sharpening (or part of a series on sharpening to be exact).

One of the popular sharpening methods is using Japanese waterstones, sometimes using a jig such as the Veritas MkII covered recently.

I like to think of sharpness of an edge as the interaction of two smooth planes. The smoother the planes, the sharper the edge. However, you can’t get a smooth plane if your sharpening surface isn’t smooth. In the case of waterstones, this means they need to be flat.

You need to keep on top of this – it is very easy to get dishing in your stone (a patch of increased wear), so a regular flattening (before and after each job would be good practice, and therefore would take little time).

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To flatten a waterstone, you can (apparently) rub two together, flattening both, but to my mind this would only really be effective if both stones were the same grade. These are not particularly cheap, so I only have one of each! The stones I have are 1000 grit and 6000 grit. That does not correlate to sandpaper if you were wondering – I will do a separate post about that shortly.

Instead, I prefer to use a known flat surface (in this case 10mm plate glass), and affix some 180 sandpaper to it to flatten the stones. It is prety easy from there – keep rubbing until the stone has a uniform surface. As you can see in the next series of images, I went a bit overboard when first using the stones a few years ago when I got them, and went way too long without reflattening them, which caused significant dishing. I have been using the other side from then on, but for this article, decided to return to the dished side, and get it flat once again.

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The first photo is after quite a lot of sanding, and still the hollow is very apparent. The second photo was with the end in sight – the dishing is almost gone. The final photo shows (finally) a nice uniform surface which means the stone is flat once again.

Sharpening demo at Carbatec

Carbatec are going to be running a sharpening demonstration morning on Saturday April 5 from 9:00AM until 1:00PM.

They’ll be demonstrating a a number of different sharpening products and methods, including

Tormek, Veritas, Japanese waterstones , DMT diamond sharpening tools to name a few.  The demo morning is free btw.

If I have a chance, I’ll definitely be heading along.

Handplanes, a quick look

I’ve been avoiding this topic for quite a while, as much because there are so many knowledgeable people about there who live and breath these traditional tools, that I know I won’t be able to do them justice. But putting that aside, there is a surprisingly large learning curve to traditional tools and what they are capable of.

Woodworking has been around a lot longer than our planers and thicknessers, tablesaws, routers, drop saws etc etc. How wood was shaped and worked was often with handtools, and a group that has survived the ages are handplanes. Of the vast majority of traditional handtools that existed, at least you can still walk into a hardware store and buy one. How good they are is another matter entirely, but there are still some quality handtools around.

I said recently that I’m a bit of a strange fish where it comes to some things, and this is no exception. I came across a toolmaker at the Melbourne Wood Show a few years ago, and was really inspired by what could be achieved with such a basic form. He was (and is) Terry Gordon, and I really enjoy owning and using some of his planes. (HNT Gordon Planes).

So onto planes themselves. I mainly only have HNT Gordon planes to show you at this stage to highlight my points. In a roundabout way, this is another aspect of the start of the sharpening exposé. After all, when you are talking about sharpening, there has to be something that needs to be sharp!

It is said that there are the big 4 planes that all complement each other, and all fill different roles.

They are: the smoothing plane, the trying plane, the shoulder plane, and the low-angle block plane. In addition, I’d add the spokeshave, and the jack plane to complete the basic set. (And at this stage, I still need to add a spokeshave and jack plane to complete my set!)

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Now I know that what I have here do not look like the planes you normally expect to see, but other than quite a different looking form to the modern plane, they still perform the same function.

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I also really like the fact they come in such a traditional looking box…

The left-hand plane is the low-angle block plane. The low angle makes it very good for end-grain, and given it’s small size, is very convenient for a number of quick shaving jobs (like taking off the edge of a board)

The plane on the right is the shoulder plane. It is unusual, because the blade gets right to the edge of the plane itself, so planing the shoulder of a tenon is achievable (and where it gets its name from). It can also be used to cut a rebate, or a dado.

The last two planes really do complement each other, and as you can see, look quite like each other, just different sizes. They do have different functions. The large plane is called a Trying Plane, and is used to flatten a board. Because of its length, it rides across high spots, allowing them to be planed down, rather than following the rise and fall and just smoothing them. It can remove quite a bit of material quickly, and is the original version of what we know as a jointer (or planer) when talking about powered tools.

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The other is a smoothing plane. Capable of removing the finest of shavings, and leaving a surface so smooth and shiny, that only a light touch with 400 – 600 grit sandpaper is needed before reaching for the finish.

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The smoothing plane can cut so fine, that you can easily read through the shaving it produces.

So these are the 4 planes, and each needs a razor sharp blade to function. In the case of the trying and smoothing planes, I have a very thick chunk of high quality steel, and for the smoothing plane in particular, I chose a cryogenically treated steel. Bloody hard to sharpen (because it is so hard), but it holds a beautiful edge. I sharpen these on Japanese waterstones, using the Veritas Mk2 Honing jig. (The blades are so thick, you can pretty easily do it by hand, but I don’t get enough practice to trust myself.)

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Here in this final image, I decided to measure the thickness of the shaving I was getting off the smoothing plane. You might be able to see it, reading 0.01mm, or in other words approximately 4/10000th of an inch (ie about 1/2 a thousandth of a inch). I’m probably beyond the capabilities of the gauge to measure that fine. I think that is thin enough!

Tool of-the-Month (February 08)

The tool for this month is the Veritas MkII Honing Guide. Veritas are well known for producing quality jigs and tools, and the MkII Honing Guide is no exception.

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The MkII is a significant development on the original jig and although it has been available for a while now, it still justifies being highlighted. It is used in setting and maintaining the bevel angle for edge cutting tools (such as chisels and plane blades).

It consists of 2 main components – the black component is the blade holder, and once the blade position is set, holds it in that position during the grinding/honing process. The other component (silver) (the registration jig) is used to set the blade position so it is honed to the correct angle. Once the blade position is set, this component is removed.

There are a number of advantages of the MkII. First and foremost is the accuracy and repeatability of setting the honing angle. The guide can be used on waterstones, oilstones, diamond stones, and sandpaper (commonly called the “Scary Sharp” technique). It has a large brass eccentric roller which can be set to a secondary position for creating a microbevel.

The setting jig not only controls the amount of protrusion of the blade (ie distance from the roller, which dictates the angle of the bevel), but also keeps the blade square so that an undesired skew is not created.

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Here you can see the stop which is dictating the blade protrusion, but also the far side has a fence which the blade is resting against, ensuring that it is square to the roller. The blade in this case is one of my HNT Gordon plane blades (which as you might be able to see, already has a mirror finish).

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Once the blade position is set, the registration jig is removed, and you are ready to start honing the blade. I’m going to be doing a separate article/video on various sharpening techniques in the near future, so won’t go into details here.

More recently, extra jigs and modifications have become available for the MkII guide, including a Skew Registration Jig for deliberately (accurately and repeatably) setting a skew angle if so desired.

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The Veritas MkII Honing Guide and Skew Registration Jig has been supplied by Carbatec, and continues to prove to be their most popular honing guide.  I’ve had my MkII Guide for quite a while now, and it has proven to be an invaluable tool where it comes to sharpening.  I had the MkI before it, and although it was a good jig, the MkII has proven to be exceptional, and I’ve never regretted upgrading.

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