Fabula Lignarius

Month: March, 2012

Hammer Handling

In december last year I was traveling in Japan together with a friend. At the time he was apprenticing with a daiku (carpenter) in Enzan, Yamanashi prefecture. During this trip I was overwhelmed with so much kindness of all the people we encountered. To this day I am still amazed by all the nice things people did for us. My friend proved to be a very enjoyable travel companion as well and since he is fluent in Japanese there is no doubt that his translating skills contributed to the good experience I had.

On top of all those nice experiences I received some beautiful gifts and one of them was a hammerhead made by the late blacksmith Hasegawa Kouzaburo who passed away in november 2004, given to me by my friend. A couple of days later we visited a tool dealer which had some very nice genno on display in his shop. Besides the hammerheads themselves I was fascinated by the  handles which where fitted to them. I have made some handles in the past but I found these inspiring for future handle projects.

The second one from the top is made from Gumi, my favorite wood for handles. I have no idea what wood is used for the short handle on top but I like the bark that is left at the end. More bark would have been even nicer, although I am not sure if it would be gentle on your skin while using it intensively. It all depends on the structure of the bark. On another one of my hammerheads, made by Masayuki, I have fitted a handle of Madrone. I left some of the bark on it which is as smooth as skin and feels really nice while using it. The bottom one is made out of Japanese White Oak and intrigued me because of it’s shape. I asked the shop owner if I could see them to investigate their shape a little better.

Last year I made a similar curved handle out of Black Locust for my funate-genno made by Hiroki. Personally I really like a slightly curved handle because it is comfortable when you are pounding on a chisel and it also tells you where the straight or rounded face is without having to look at it first. You just feel wether you are holding it right. The rounded face of a genno is often used to compress the wood fibers, this is done to ease the assembly of tight joints. Because of the moisture in the air, the wood fibers swell back and this establishes a very good fit.

The curved handle shown in the first picture felt so good in my hand that I decided to copy it for the Kouzaburo hammerhead I got as a present. I was amazed by the thinness of the handles I saw and it is because they are so thin that they felt good in my small hands.

Especially the Gumi handle flares out quite a bit towards the end, I like this widening to be a little more subtle. Before I left the shop I copied the shape of the White Oak handle on a handle blank so I could make one for myself later. It is not visible on the picture but none of these handles where fitted to the head using wedges to secure them. I have tried to do this in the past but they always came loose again and at some point I had to wedge them anyway to secure them. I knew that, when done correctly, they shouldn’t need a wedge and would be secured for a very long time.

I shaped the piece that I brought back from Japan roughly with a rasp. Then I scraped the surface to a smooth finish leaving the top of the handle a little bit too wide and thick, about 2mm in both directions. I should have documented the whole process but when I am working I never think about taking pictures. I will try to remember next time.

In the book ‘The Soul of a Tree’ by Nakashima I saw a picture of how they dry out tenons with a ultraviolet heating lamp to shrink them to minimum size before the tenon is inserted in the mortise. I decided to use this approach in the hope I would be able to fit the handle super tight without a wedge. I left the top of the handle in front of the lamp for about 24 hours and I guessed that should be enough to have it shrink sufficiently. At first it seemed that the handle needed to be shaved down a little more but with gentle persuasion I was able to insert the chamfered handle top into the hole by just a millimeter.

The hole of the hammerhead needs some explanation. With a good quality genno the hole is flared outwards towards the top. This does enable you to fit a handle to it without the need for a wedge. Also the bottom side of the hole, where you insert the handle, has a small chamfer on it. This prevents the wood to tear off while inserting the handle. On the pictures below this chamfer is not visible since the wood has swollen back and covers this chamfer.

As soon as the handle is inserted you can drive it down deeper by pounding the bottom with a wooden mallet while you hold the handle in your hand. Don’t place it onto a bench, inertia will drive the head onto the handle. I found the color a little pale in combination with the old used head and decided to smoke it with some ammonia before applying pure Camellia oil onto it. With pure I mean pure. Here you see the bits of the Camellia nut which I used to rub the oil into the wood surface.

This is the result. I like how the shape turned out and it feels just right.

Just a gentle widening et the bottom part.

Tools always look so much better after a couple years of intense use and good maintenance. So let’s put this clump of steel to use…

The Damage Undone

This morning a friend of ours, who is a professional welder, came to see wether he could fix the thickness planer which was badly damaged after ‘the loose blade accident‘. In his shop he already repaired the bracing arm which supports the infeed table. This part was cracked in half and I was convinced that it would be difficult, not to say impossible, to fix. He proved me wrong and was able to weld it back together and bolted a reinforcement plate to it for increased strength and support.

One of the broken pieces clammed into place and prepared for welding.

I just love projects like these. This beautiful chunk of cast iron will not find it’s way to the landfill if we can help it. It had 60 years of active duty and can easily have twice as much if we just make an effort to continue it’s life. We will not give in to the desire for more consumption and just go out to buy something new instead of repairing what is left.

Applying liquid metal.

Many people who we talked to tried to convince us to buy a new machine. Arguing for the service which comes with it, the ease of use, and the lack of all the stress or time we invest in fixing it. They forget to mention that a new machine, which would fit our budget, would be a cheap piece of junk made with low grade components and can only be described as a true waist of precious resources. Most of the new machines I encounter like brand x, brand y and brand z, just to name a few, fall in this category. They might suit the enthusiast weekend woodworker but are not suitable for anything else then home, garden and kitchen use. Any of the new machines that I really like are way behind our budget. This leaves us searching for those unwanted oldies which we are happy to give a second life.

Pretty clean, but even more important,very accurate welding job.

In the next one you can see the support of the infeed table repaired and installed. It sits on top of the arm which got welded back on. Note the four bolts which connect true the piece into a plate on the back side (plate not visible). The plate in the front will be installed as extra reinforcement and to dampen vibrations around the weld.

Installed some new planer blades today and if everything goes well I can plane some wood tomorrow. How nice would that be? All depends wether I can adjust all the components to line up the way they should. But since they are all so finely made, this shouldn’t give me any difficulties. The sooner it is up and running the better, then I can dimension some wood and get back to the hand tools which I like to use even more then those noisy giants…

Too many Machines

Because of the event that caused the failure of our thickness planer (see here) my companion and I have been looking to acquire a new machine. Last week we went to have a look at one which seemed to be promising. Upon arrival we immediately started to investigate it so thoroughly that our seller was a bit impressed by our demands. It became clear that the two tables of the jointer did not line up the way they should. We ended up taking one of the tables off, cleaned it all up and put it back together only to find out that the tables where worn out and the fence a bit crooked. Someone must have taken it off at some point and dropped it on the floor causing one of it corners to bend slightly. Amazingly it still performed well enough but we decided those items had to be addressed before we would be able to put it to use. It would cost us about 500€ to have it fixed on top of the 800€ to buy the machine. Plenty of reason to have a look at some other options. In the end we decided we didn’t wanted to buy this one but left the seller satisfied because it was now in better condition as before since we performed some serious maintenance on it during our inspection.

My companion found another machine which is in pretty good condition and has no apparent issues. It is a good candidate but a little bit too large for our limited working space. It is a combined machine with also has a tennon-cutter, and shaper build into it. Those combined machines are quite popular in Europe and are easily found for sale on the second hand market. Most of the time they are intended for the enthusiastic hobbyist and not all that suitable for a professional shop. This one on the other hand is a fine example of a machine that is accurate and well made capable of being used constantly in a professional production environment. The brand name slips my mind and unfortunately I can’t post any pictures of it now.

My comrade told me the good news of his find and explained me there where many machines for sale there. He found it in an old machine shop ran be a machinist who is now too old and blind to continue his work. An alarm went of in my head instantly. A machinist who is selling his old machines is like a dream coming true! There is no place where there is a greater chance to find good, well build old machines which are maintained well, then in a machinists shop. I grabbed my phone gave them a call and asked for an appointment.

Yesterday I went there with my father to have a look and yes, my presumption was correct. The machinist daughter is taking care of the shop and she is a very friendly lady who was happy to receive us. We told here that any of the machines we would buy from them would be maintained well and put to good use.

There are three machines that have my interest and fit my budget. First there is this beautiful old ‘Danckaert’ bandsaw made in Brussels. It runs super smooth, the bearings are not worn out, the motor is in fine condition and they ask 500€ for it. SOLD!

Then I found this really nice drill press which I tested and is in very fine condition. It will take some cleaning and greasing but it is dead accurate and very well made. The gear system is the nicest I have ever seen on such a drill. For the enormous amount of 250€. Yes, I need it! It also comes with two clamps which fit the table.

And then I found this grinder with two precision tables attached to it. I will be using this one to regrind drill bits and similar cutting tools. I am still contemplating wether I will buy this grinder but my companion already told me that he will get it if I don’t. It is just too nice and useful not to get it while we have the chance.

As you can see in the background the shop is full of machines and they are all in fine condition. Luckily I am not a metal worker or I would have tried to get all of them. I saw many useful hand tools which they sell for the price of the old metal. I need to reserve a budget for all those things as well.

I am still overwhelmed by all the goodies I saw and need to contemplate whether I will buy all three of them or just the bandsaw and drill press. As soon as I made a decision and they are up and running in our shop you will get a review on their true performance…

Freehand Sharpening Workshop

Yesterday I gave a workshop in freehand sharpening for woodworking tools. It was an event that I had planned for quite some time and put considerable effort into preparing it. In the past I have given many other workshops but those where never related to woodworking and had a very clear outline and accompanied established courses. With some experience I was convinced that I could get away focusing my prep work on the written essay that companioned the workshop. I should have paid more attention to the presentation since I had a hard time to get started and lost track of what I was explaining a couple of times. After a slow start things started to get rolling and all was good.

I sincerely hope the participants where able to understand the basics of freehand sharpening and where gained some understanding in the essence of it’s mechanics. Besides that it was my goal to share me passion for the subject and lower the threshold to work freehand while sharpening. I am still not sure to what extend I succeeded in my goals and was only able to tell about half as much as I wanted. It would have helped if I had worked out a fixed timeframe for the different subjects but I was too careless to give that enough attention. In the end I hope it was a success, it is too early to draw any conclusions. Only if most of the participants will actually start too sharpen freehand I can evaluate it’s effect. We will see…

It was a good learning experience for me as well and I am sure I will approach the organization of a workshop slightly different in the future. The subject of sharpening is so broad that seven hours is just too little too cover all the subtleties that come with it. At the end of the day I was happy to see some good results with most participants which are on their way too become confident free hand sharpeners.

There still remains a lot of work to do on the essay and I hope to finish that by the end of april to make it available to a broader public. I will keep you posted on it’s progress…

..Coticule.. the sequel

After writing the second post of this blog, where we discussed the Belgian Coticule, I continued my research on the topic and came to the conclusion that there is much more to be told on the subject. In order to give a complete and in depth report on these stones I have a lot of work ahead. I also noted my poor writing style and some grammatical errors. I hope to improve myself but this will take time and effort.

First I should address some errors, some of the statements I previously made are just plain wrong. My apologies for that! I could have chosen to edit the previous post but instead I will leave it as it is and present some more accurate information in this sequel. The original Coticule post will remain a silent witness of my steep learning curve in blogging.

Coticule is a composition of two Latin words cotem or the feminine diminutive form of cos, cotis which means whetstone and ‘novacula’ which means razor. A whetstone for razors so to speak. (Not to be confused with the Novaculite which is a family of American oil stones, the famous Arkansas Stone is one of them but these have very different properties.) It is mainly in this subculture of straight-razor users that this stone is still extremely popular and they are probably the largest community who still uses them today. We will not discuss the Coticule in the light of shaving, only in relation to sharpening tools for woodworking.

The active sharpening particles are properly referred to as ‘spessartite garnet crystals’ or simply garnet. I referred to them as ‘granaat’ which is the Dutch equivalent and therefore it was printed Italic. These particles turn out to be larger then I thought and instead of 2 micron they are actually 10 to 15 micron (other sources state 5 to 20 micron). Because of the shape of the crystals, which is to be compared to a rhombic triacontahedron, it is only the edges and corners of the crystals that scratch the steels surface. It is the depth of the scratches created by the garnet crystals that is about 2 micron deep within good quality stones. This makes sense if compared to a Shapton Glass stone where the abrasive particles are 1.84 micron in their #8000 stone.

On the Mohs scale of mineral hardness, Talc has a hardness of 1 and Diamond has a hardness of 10. Garnet is rated between 6.5-7.5. Other abrasives commonly used in synthetic sharpening stones are aluminum oxide with a hardness 8.0-9.0 and silicon carbide which scores 9.0-9.5 . This might give you an idea of the particles hardness but to me it remains subjective how this translates to the quality of an edge sharpened with a Coticule.

My little research revealed another interesting fact. I have always been told that Coticule was only found in Belgium but apparently this is not the case! In Nova Scotia there are very similar veins of Coticule to be found. The veins are intricately folded in most places and not thicker then 1/3 inch leaving them useless for the purpose of mining sharpening stones. It also remains unclear to me if the content is the same within the stones from other regions. The Belgian Coticule layers are originated around 480 million years ago and I couldn’t find any dating regarding the Nova Scotia rock. Further reading revealed that there are similar rocks to be found in Massachusetts, Wales, Ireland, Norway, New England and Newfoundland. So much for the ‘only in Belgium myth’. Eventually it became clear to me that many rock types which are slightly different in origin and content are referred to as Coticule. According to J. A. Thompson, “Coticule’s are garnet-rich quartzite’s and are chemically distinctive lithologies of controversial origin.” It is a field term to describe fine-grained garnet-rich granulites which leaves room for interpretation. To make a fine sharpening stone the garnet crystals must be sufficiently small and the quartz must be finely grained, this is only the case with Belgian Coticule’s I suppose.

The sole miner of the Belgian Coticule’s only makes a distinction in two qualities which he refers to as “standard” and “selected” (see this page). I believe this is rather inaccurate and contrary to what is stated I think there is a clear distinction in the quality of these stones. I have used many different qualities of Coticule and I could easily place all the stones that I have ever used in order of hardness, edge quality and consistency. I use a handheld x200 microscope to evaluate my edges and this is already sufficient to see a clear distinction. When the edge quality obtained with a certain stones is evaluated it becomes clear that stones form different strata have different properties.

One of the employees of the mine who is a geologists is actually trying to establish a grading system based on the different geological layers which occur in the region. This clearly indicates that my personal conclusion might hold some truth. The owner of the mine also employs a more distinctive grading system which is only used internally in his business. He distinguishes “3th quality” for stones with severe cosmetic flaws, “standard quality” for stones with some cosmetic flaws, “selected quality” for stones with no cosmetic flaws and then a 4th grade called “Kosher” for those rare specimens that are absolutely impeccable. His grading system relates only to the appearance of the stones but also this can be an indication of their performance.

If we would like to come to an indisputable conclusion it would require some serious and complicated scientific research taking into account all possible variables. It would be an interesting study but good old wisdom based on experience is sufficient for me at the moment. I will happily revise my conclusion since I always seek to learn and broaden my views but so far I could not conclude that the amateurish research on the performance of the sharpening stone is convincing in any way. There are to many variables which have been left to personal interpretation. Of course this is also the case with my own conclusions but nonetheless I stick to them for now.

The Belgian Blue Stone, originally known as ‘La Dressante au Blue’ , is worth discussing as well. Let’s look at the etymology first and see what we can conclude from there. ‘Dresser’ could mean as much as ‘set up’, ‘lay’, ‘set right’ etc. . This leaves me to speculate that the Blue Stone originally was used as backing material for the fragile white Coticule layer. This is backed up by the fact that until recently there where companies specialized in cutting the Blue Stones used for backing material. And they where able to use the best quality Blue Stone the could find for it. Those where found adjacent to the Coticule layers because only there the Blue Stone contains sufficient garnet crystals to make for a decent sharpening stone on its own. There are only a few blue layers that are suitable for mining Blue Stones that are to be used for sharpening and  small pink dots in the surface of are an indication for good quality. Today they use a Brazilian slate flooring tile as a backing material because it is more economical and easier to acquire in large quantities. Therefore it remains to be seen if the ‘modern’ backing stones can be used for sharpening because of their different properties.

If you are looking for a fast and homogenous natural sharpening stone which will give you a fine edge on chisels and plane blades not used for finishing, then almost any Coticule will do except the lowest grades. The Belgian Blue Stone has less garnets then a Coticule and is therefore much slower and since they tend to be quite soft and less fine I categorize them in a different league. When you are looking for a really fine stone of exceptional quality, my suggestion is that you can delve into the subject yourself, gain experience with using them and then endeavor on a search which might take some time. Maybe we can look into the different types of Coticule but I will leave that for the next chapter on this marvelous stone…

Shrapnel

Last week I called one of my comrades, a fellow carpenter, to tell him the good news that a job was landed in which we put invested a lot of energy to get it. Before I could tell him the good news he said quite nervous that he just had an accident that day but luckily he didn’t get hurt. He told me what happened and ooh boy was he lucky! It was a typical carpenters accident and it could have easily been a really bad scene.

A couple of months ago he was looking to buy some old, high quality, second hand machines. Together we searched the internet for a bandsaw, planer and thicknesser. We found some nice machines for a reasonable price and it was one of these machines that he was fine tuning when it happened.

He was working on the machine and re-installed the blades to see if they where aligned and went for lunch. After lunch, happy with his achievement he turned on the machine and with 380 volts and an immense amount of power it started spinning effortlessly. He was amazed by the smoothness and lack of overwhelming noise and then    BANG !!

So what happened? After resharpening the planer blades he inserted them back in the proper position but didn’t tighten the screws which press a clamping piece against the blades to secure them since he’s lovely wife called him inside for lunch. When he’s lunch was finished, and most of his blood was still digesting the good whole foods served to him, he’s focus was not optimal and he turned on the machine instead of continuing where he left off.

When he told me what happened I was very happy to be able to talk to him alive. It also reminded me of my mentor who has told me so many times to always double check if you have tightened the planer blades after sharpening, and it is only on such a moment that I really understand and appreciate all the effort he put in teaching me proper machine maintenance. Accidents like that can happen to the best of us and constant awareness is never obvious.

The machine itself is one of these old cast iron very well made monsters. They don’t get any better then that. Nonetheless many of the parts broke and as you can see on the picture there is some serious force necessary to do damage like that. Another part is already send to be repaired and we will try to fix the machine rather then bringing it to the old iron merchant. I am not sure if it’s going to be possible to fix it at all but we will try. If we succeed I will post pictures of our success. If pictures never appear well.. then you know what (didn’t) happened.

Here you get some idea of the damage. Since the accident I still find pieces of shattered blades as far as meters away buried deep in pieces of wood.

We are in need of planer and thicknesser that is why we have been looking for a new machine. This weekend the search will continue and maybe we will buy another one since there is work coming up and the repair will take some time…