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Posts Tagged ‘Tool Making’

Naturally, once the keelson with the stem and sternpost were glued on I had to spring a batten through the shearline, bend over, and look at the shear with my head upside down. With the batten sprung through the locations on each frame dictated by the lofting, the shearline looked quite fair. With that out of the way, I thought I was just about ready to begin planking. You know, beveling and scarfing had to happen first, but the planks would be flying on within a day or two, right? Well, it turns out beveling takes time, and though I might have wished it had taken less time, I get the distinct impression that it it time well spent. I broke out two bevel squares, a sharp one inch chisel, my Stanley number 4, and set to work.

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After many hours of moving the batten from chine to chine, just above a chine to below a chine, springing the batten back around spots to double check my work, and finding the proper angle to work each various spot of grain on each frame, pieced together stem or stern post, keelson and bulkhead, the beveling is done.20140328-113008.jpg

Beveling the number 2 and number 4 frames provided a distinct satisfaction as the lamination lines showed up as these wonderfully nested eliptic curves within each angled facet of the curved frames. The juxtaposition of the angular beveling, which reminded me of the facets on a finely cut jewel, with the curves of the inner surface and the lamination lines on the facets is really beautiful, and was a very pleasant surprise.

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Working the curve of the step and stern posts was also an interesting challenge, and I’m pleased with the results. I found that starting with a sharp chisel for heavier removal of matterial, followed by smoothing the curve with a sharp plane to be a fairly efficient method. Depending on the grain and angle I was working at I would often return to the chisel for finishing touches.20140328-112641.jpg

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Somewhere in there I also scarfed the wood for the garboards. It also turns out that with everything set up, its hard to create 16 feet of length within the shop. I planed the three inch scarfs down, starting with my Stanley number 4 and fine tuning the surfaces with my old Stanley number 6. Its a good thing 3/8 inch plywood is as flexible as it is, otherwise I don’t know how I would have glued it together, but I managed.

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20140328-113112.jpgSomewhere along the way I started thinking about my future need to plane the gains in the planks and my lack of a suitable rabbet plane. Well, not entirely true. I have rabbet planed available to borrow from the Wind and Oar Boat School, and there was also that old Stanley 78 hidden in the back of a drawer that I had. Hidden because it was too shameful to look at. At some point as a kid I acquired it, including the old Sweetheart Stanley 78 including depth stop and fence, but I never had many uses for it at the time. It spent a long period of time in a wooden box, and at some point that box attracted some moisture, and somewhere over the intervening years almost every surface without the black paint proceeded to rust. It was painful to look at and I didn’t know how to fix it, and apparently didn’t have the incentive to do so until now.

Last weekend I was talking with a guy while working on the Crosby Catboat owned by the Wind and Oar Boat School. He suggested using a toilet bowl cleaning product called “The Works.” So I tried it. I dismantled the old plane, and put it into a solution of water and this product. After about a half hour I started removing pieces and scrubbing them down with a wire bristled brush. Bit by bit the rust started coming off. With just a few hours work, the old plane is no longer something I need to feel ashamed of! Too keep the parts from rusting again, I quickly dried all the pieces in a toaster oven set to the lowest temperature and rubbed them all down with a fine coating of grease. I sharpened the blade, reassembled the whole thing, and it looks ready to begin cutting gains!

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Gotta love the old script used for the Stanley logo on this vintage of the Stanley 78. Anyone know for which years they were marked this way? It doesn’t have the blade adjustment lever, but the blade does have the heart logo on it.20140328-112908.jpg

Next step: Patterning planks!

 

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Skew Chisels

I realized that I had never posted pictures of the skew chisels I made the blades for in the tool making class I participated in a while back. Except for some final sharpening and fine tuning, the blades were finished as part of the class, but we did not make the handles in the class. For a little while I was lazy and used an old file handle, but the blades clearly deserved better. To remedy the situation, I turned a matching pair of handles out of some maple I had laying around. I made the collets out of a piece of copper tubing from the plumbing section at home depot. I turned the front of the handles carefully for a pressure fit of the collets. I drilled the holes with a deeper narrow hole and a shorter wider hole to better hold the tapered tang of the blade. The handles were sanded and finished with a single coat of linseed oil.

At this point, I probably reach for this pair of chisels as much as just about any tool I own. They were great for trimming the bungs for the top of my tool bench recently, but I seem to constantly find new uses for them as I work to sneak into difficult corners or work with stubborn grain. Custom making the handles also allowed me to create a shape that fits my hands as well as any tool I have ever owned. They are truly a joy to use.
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Knife sheath

This is a project I actually finished during the fall, and had not gotten around to posting until now. This was my first real experience with leather work, so I was not entirely sure what to expect, but it seems to have gone well and I am happy with the results. Here is how the process went.

The first step was to create a pattern Which would have enough leather to wrap around the knife handle and blade. I was getting bits of advise from a book called Knifemaking by Bo Bergman. It seems like a bit of a goofy book to me, since it actually doesn’t talk about making the blade at all, but is really just about making the handle and sheaths, but it does have lots of good information on those subjects. One of the sheaths presented in the book had the leather seem forming a spine down one side of the blade and handle, so I used that model as the starting point. I drew the silhouette of the knife and then added width on each side of the silhouette so that the leather would reach around to the center of the opposite side of the knife. I then added a little extra width on each side of the resulting shape to provide the extra material for the sewn spine and for the clamps to have plenty of material to hold onto. I think this step may be easier to see in pictures than to hear described. You can see the silhouette with extra width added drawn on the piece of paper to the right of the knife.

Next, I traced the pattern on the piece of leather and cut it out with a scalpel. My girlfriend keeps scalpels around which are surgical quality, but not sterile for bookbinding, and I have to say that they are awesome to use. Much sharper than any X-acto knife I have used.

To mold the knife around the knife, I first had to protect the knife from the moisture. I coated all exposed metal with some grease I have laying around for bike parts, and then wrapped a few layers of plastic wrap around the whole thing. To make the leather supple, I soaked it in warm water for about 15 minutes. A combination of small spring clamps and c-clamps with wood pads were used to hold the leather snugly around the knife. It took some work to get the leather pulled as snug as I wanted, but it was pretty simple to clamp parts of the sheath while working to get other parts more snug, and then cycling back around until the leather had formed around the knife to my liking, and so that the spine followed a path I liked. I left the sheath clamped up like this for 3 day so that the leather could fully dry and take on the shape of the knife.

After molding the body of the sheath I cut and molded another piece around the sheath around the handle of the knife. I decided to add this piece so that I could cut a channel in the body of the sheath for the sharp edge of the blade to pass through while pulling the knife out or putting it back in. This piece was also cut to have the belt loop.

After allowing the second piece of leather to dry for several days, it was time to begin sewing. The sewing required consideration to figure out a procedure which would work best. Regardless of which order I sewed pieces in, there would be some part that would be difficult. I believe the order I came up with was the optimal one. The first seam I sewed was the spine. I used a single piece of thread for sewing across the tip all the way to the opening of the sheath. I had two needles going at once, so each end of the piece of thread went through each hole. After sewing the spine I sewed the part around the handle on. To sew each side of that I first drilled the holes with a 1/16th inch drill bit, and I then cut the needles short so I would be able to maneuver them inside the sheath. Like the spine, I had two needles going at once. I also used additional needles to keep everything aligned correctly. Pushing the needles in was easy, turning them around and pushing them back out was difficult, but I got a system down which made it go reasonably smoothly. I used needle nosed pliers on the inside to hold the needle and then put a needle in the same hole that I was about to go out of, just far enough in to see the tip and give myself something to aim the needle on the inside of the sheath at. I would gradually pull the needle on the outside back out of the hole while working the needle on the inside into it. With the predrilled holes, this process went well. I imagine it would have gone poorly without drilling.

To finish it off I rubbed a little Obenauf’s leather preservative into the leather to slightly darken and protect it a bit from staining or water damage, but otherwise left it its natural color. The knife fits snugly in the sheath, and I am pleased with how it looks. It feels like I should be able to get a lifetime of use out of it.

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On Saturday we began the heat treating process on the blades we shaped out two weeks ago.  When I arrived the electric furnace was already on and the first batch of tools was already inside. Here is the process we are using to heat treat the blades. This is the process Randy came up with after his research into the subject, and by his own admissions, parts of the process are not ideal for all blade types, but they represent a good middle ground for the blades we made and considering that we are using 01 tool steel.

Our blades were first heated to 1500 degrees Fahrenheit in the furnace. To make sure the blades were hot enough, a magnet was used. When the steel is hot enough, the magnet will not be attracted to it. The blades were taken out of the furnace one at a time using tongs and they were quenched in peanut oil. I am not sure why peanut oil specifically, but that is what we used. When quenching the metal, we were conscientious about getting the entire blade submerged quickly. If the blade is not submerged quickly, the oil around the blade will be heated to a high temperature and the metal which has not been submerged can ignite it.  For obvious reasons, this is not considered desirable. After the blade had been cooled quickly in the oil, making it very hard, the blade would be quickly toweled off and put into a toaster oven set to 350 degrees Fahrenheit to temper it.

The hardening makes the blade hard enough that the edges of the tools would be brittle. By heating them to 350 we changed the crystal make up of the metal, resulting in much tougher and more durable tools. Randy said 300 degrees would likely a better temperature to heat the skew chisels to considering that they are not designed to be used with mallets,  and that 400 might be better for the marking knife, but that 350 would be a nice compromise within the context of the class.

The previously described steps were completed in the class on Saturday. We were instructed to heat them again to around 300-325 for an hour or two to further refine the temper. The final stage for tempering process will be a cryogenic temper. That stage will occur in two weeks during the plane making class, where we will cool the blades in kerosene cooled with dry ice for 24 hours. Don’t ask me what the chemical changes are that occur, but it sounds pretty neat and should help us end up with some really nice hand made tools.

Here John and Jim are removing tools from the furnace and quenching them in the pot of peanut oil you can see at the bottom of the photo:Here are my blades after a little clean up. I have relieved both sides of the skew chisel here and tapered the tang to it into the handles I will be making:

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Last Saturday I took a one day class at our local sustainable small boat center; the RiversWest Small Craft Center. The center is a small member driven organization which you pay minimal dues to join ($50 per year), and which works to support the local sustainable small boat community through a variety of avenues, including the use of their library, tools, hosting classes, and with an additional monthly fee the ability to use one of their bays to build a boat.

This was the first class I have taken with them, and I was looking forward to learning some different techniques for tool making while also getting to know more of the members. It was taught by Randy, a member at RiversWest. The goal of the class was to make a Hock style plane blade with chip breaker, a marking knife blade, and a pair of skew chisel blades. Next month there will be another class where we will build a wooden plane body. For the plane body, there was the option to build a regular blade or to spend a little more time and make either a scrub plane or spar plane blade. I chose to stick with a straight blade during the class, though I would like to also build both other types at some point.

We started with several foot long lengths of 01 tool steel and cold rolled steel for the chip breaker which had been purchased from McMaster Carr. All the students had made basic jigs before the class which were used on the bed of a belt sander to establish the correct angles of the different bevels we would sand down in each of the blanks. My jigs were made from scraps of 2×4 and bits of leftover 1/4 inch thick cedar strips from building Abigail. The jig plans can be seen here.

To make the plane blade, I first ground the 30 degree bevel. With the bevel ground so that only about 1/32nd of and inch remained flat, I used the jig which had been made to drill a hole for each end of the slot in the middle using a light weight oil to keep the bit well lubricated and drilling each hole slowly. The next step was to drill a series of holes between the ends that either slightly overlapped or almost overlapped to remove the bulk of the material from the slot. A rat tail file was used to link the holes, and a flat file was used to straighten the sides. I was surprised at how little time it actually took to straighten the sides. The 45 degree bevel was ground next on the chip breaker. A hole was then drilled in it and tapped with a 1/4×20 thread tap. To dress things up, we used pennies to mark a radius on the back corners of the blade and chip breaker and those were ground. With that, the plane blade was ready for heat treating.

Next, I used the other jig to grind the bevels for the skew chisels and marking knife. The jig worked very well for the skew chisels, but left what seemed like an awfully obtuse angled spear front on the marking knife. To sharpen the angle of the marking knife spear point I held one side of the jig closer to the sanding belt to the other. That allowed me to change the angle of the edge to the side of the blade from about 60 degrees (so that where the two bevels came together the angle was about 120 degrees), to about 45 degrees, which resulted in about a 90 degree spearpoint which still seems a bit more obtuse than I would like, but I will give it a try and if it needs to be adjusted, I can do that. Though I did not get to it during the class, the sides of the skew chisel will need to be relieved near the blade, and I will need to grind the tang narrower to fit better into a handle.

Originally, the goal was to begin heat treating the blades during the class, but there was a wiring issue which would not allow us to plug in the oven we intended to use. That portion of the class will be completed in two weeks.

All told, I’d say the class was a success. My blades look great, and I look forward to being able to use them.

Here is Randy working on his chip breaker:

 

We cut some of the blades by hand before the bandsaw arrived:

 

Here are my blades:

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There is some more finish work to be done, and I want to make a sheath for it, but over the weekend I was able to attach the handle to my knife without breaking anything. Thanks to Dave for his comments on how to attach the handle. I got back to work on the knife and successfully attached the handle before recieving the comment, but I really appreciate the suggestions! Some of the ideas he proposed were ones I had used, there were others were things I would like to try if I find myself making another knife.

Here is what I did:

My first step was to create new wood scales (apparently this is the technical term for the pieces of the tang on each side of the blade). I had some of the same scraps of walnut that I had used to make the spline weights, so I cut them to rough size and then drilled the rivet holes in them, using the existing holes in the blade as my template.

My next step was to make the rivets. I decided (this was also suggested by dave) to round over one side of the rivet before using the rivets to attach the scales. To do this, I drilled a hole in a scrap of oak that was just a bit shorter than the pieces of soft drawn copper wire I was using as rivets. I placed each of the pieces of copper in the hole and used a regular hammer to round over the top. The pieces ended up being a little bent along their length, so I gently hammered each of them straight again.

Next I clamped all the pieces together. The copper was slightly narrower than the holes, so instead of relying on them to align the parts, I used the drill bit to align the pieces as I clamped them together. By making sure the holes were more nearly vertical, it seemed like I could minimize the leverage which could split the handle. Next, I added clamps with pads of wood which were in the front to back direction of the blade, which would apply pressure to resist any forces to split the handle again. Next I put each of the rivets into their holes to test fit them, and cut or ground them down to their final length. The length I cut them to would have very little extra material, or more importantly, length which could act as a lever to split the handle.

The extra prep work left me feeling pretty confident that things would work better, so I started pounding them over. I used the back side of a splitting wedge held in a vise as my makeshift vice, holding the knife with one hand and hammering with the other. The sides I had already rounded over sat only slightly proud, so I was able to concentrate on just one side. I found that by using the edge of the hammers face, I could round the rivet over much more efficiently and with less force than by using the flat part of the face. I had to shuffle the positions of the clamps occasionally to get better access to rivets, but it was never too awkward. When that side of the rivets was finished I flipped the knife over and did a little finish work on the side of the rivets that had already been rounded over to better fit them into the slight countersink I had given the holes. The new procedure seems to have worked out great. Dave recommended that I ditch the leather and also that I epoxy the scales on, neither of which I did, but if it turns out this handle is not as durable as I would like, I can always go back and try those ideas.

The handle has been shaped, sanded and has a coat of salad bowl finish on it now (its what I have laying around). I will be applying more coats of finish and making a leather sheath for it. When the sheath is finished I will add a post about that process.

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Progress on knife

I got the blade hardened and tempered yesterday and then tried to attach the handle. I had done all the work on the blade to date with the metal fully annealed. To harden the blade, I used a bernz-o-matic torch that uses mapp gas and oxygen. Its cheap and reasonably easy to use. I was able to heat the blade from about halfway up the tang to the end of the blade to a nice red glow at which point I quenched it in water. To temper the blade, making it tougher and less brittle, I put it in my over and heated it to 480 (Please note update below) degrees for about 25 minutes.

Where things unravelled a bit was rivetting the handle. I am trying to use soft drawn copper wire for the rivets, and my drill bit is slightly larger than the wire. Due to the imprecise fit, and trying to alternate between pounding the handle on one side of blade and then the other, the copper ended up bending off to an angle and splitting the wood. I am also using leather pads between the wood and the blade to fill some of the spaces where the blade is not completely flat, and that may also be allowing the handles to move more easily and cause problems. I have some ideas for what to do next time to prevent splitting. We’ll see how it goes.

Important Update(!): After using the knife for odds and ends over the last few weeks, it looks like I tempered it at too high of a temperature. I don’t know if temper heats for a desired hardness vary with different grades of steel, but 480 was clearly too hot for my knife. If I were to do it again I would probably try 375. All that being said, the knife works fine, it just looks like I will be sharpening it more frequently than I would like.

 

Back to the drawing board.

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