[Warning: Long post]
First post here, to introduce myself. I also writing with an altruistic purpose. I've seen here a handful of first knives here that look absolutely amazing. As those can be most intimidating to prospective knife-makers, I feel it is my duty to show what a mere mortal accomplishes when he does not try hard enough and he neglects too much good advice.
For some of the more experienced, maybe this may help you to remember that first experience and laugh.
I got interested in knifemaking last year. I like cooking, but after about 25 years of being an enthusiastic amateur, the best piece of cutlery I had was this http://cdn.norecipes.com/wp-content/uploads/2009/09/knives-41.jpg. It was ultra dull after years of NEVER sharpening it. I just used a steel, thinking it was good enough. I decided to fix the problem by buying a set of decent, affordable knives and some sharpening system. I went online and discovered that "choosing a knife is harder than choosing a digital camera," as someone accurately described. I settled for some Forscher knives and a Japanese waterstone. Then I was reading a lot about how to sharpen a knife, which lead me to learn about the different kind of steels, and the heat treatment procedures. Soon I was reading about knifemaking and I was hooked. I never cared much for hobbies of this kind but I had to have a go at it.
I cannot make knives at home because I live in a 1 bedroom apartment, but my dad has a small farm, and there he has a shop with a number of power tools he uses mostly to maintain the heavy machinery. He also used to make furniture for fun. On top of that, he is retired, which means he has time to fool around with a project like this. I thought it was going to be a nice way to spend some time with him, and I was right. As soon as I emailed him about the project he was off to buy some old circular saw blade. He got a 10" one, of unknown purpose and origin for $3. No one can blame him for lack of enthusiasm.
Meanwhile, I was thinking that, maybe, a baby step approach was wiser. Wouldn't it be easier if we started from a knife to get a knife? Maybe restoring a beaten up one was the way to go. I remembered the "big, good knife" my mom used in the kitchen when I was a kid, and I remembered seeing that knife sitting in a drawer for years. I emailed asking about it and dad said he had being using that knife to cut aluminum/asphalt membranes when fixing the roof. He sent me the picture of what was left of it. The peculiar blade shape is a consequence of years of my dad's overeager approach to sharpening using the grinder. So this was the plan: Recover as much as possible of the old knife and get a few blades from the circular saw blade.
I threw the old knife blade into a bonfire to anneal it (or whatever would happen to the mystery steel), and while waiting for the logs to consume, I asked mom about the knife and how she got it. She answered "your grandmother bought it when she was 22, right after she got married." I felt as if I had thrown a 75 year old family relic into the fire. The next day, I straightened the blade as it has curled up a lot. With some help from my brother in law, AKA Bichi, I profiled the blade using an angle grinder. I removed the badly corroded tang section and Bichi was kind enough to arc weld a piece of mild steel to replace it. He has a small shop were he makes skid plates for motorcycles, so he has some interesting tools there.
Then came the time for the first heat treatment. My dad talked me into using the living room salamander stove as a forge, using a combination of charcoal and a propane torch for heating. I did not liked the idea of deviating so much from conventional protocols but it certainly saved time. Now, plunging red hot steel into a bucket of used motor oil from the bulldozer in your living room sounds like a bad idea simply because it is. Luckily for us, mom was not at home that weekend. The blade of that knife is so thin that I used two thin plates of mild steel to improvise a scaffold to prevent warping. We heated it up until it looked cherry red to us, soaked it for like two minutes and quenched it. I guessed it worked, because the blade hardened and was still straight. I tempered it in the kitchen oven (no thermometer, of course), for 1 hour. Here is a picture of the blade after HT and some sanding. Note how the mild steel melted while welding it, forming a hole.
I made the scales out of a hammer handle. It's some white wood, with very even and faint grain. Mystery wood should go well with mystery steel. I epoxied it, used cyanocrylate to seal the ends and I used some wood finish product on it (Petrilac) http://www.petrilac.com.ar/eng/producto.php?producto=16&uso_linea=linea&uso=. Here is what it looks like (I repolished the blade for the picture only, I will force a patina at some point).
I made it months ago so it is a bit dirty by now, but is not that it looked much better when it was new. Fit and finish is definitely sub-standard. The tang piece was warped and the thickness of the mild steel addition did not match the original blade's.
I sharpened it with my waterstone (that I can do reasonably well) until shaving sharp. The tip seems to be softer than the rest of the edge. Maybe a defect of HT. Maybe the blade was so thin (the spine is about 0.055in thick and the blade is tapered) that the tip cooled down before getting into the quenchant?
It is very basic and not terribly well executed, but it is usable.
The same day we filled the living room with burnt oil smoke, we also HTed two blades that came from the circular saw blade. For the sake of science, we used water as quenchant and both blades cracked. One of the blades was an approximation to a santoku. It didn't just crack, it bent in a funny way, much like a spherical sector.
It was time for a more scientific approach. I googled for whatever was written on the blade. It turned out to be a bush cutting blade, made out of SKS5. There was enough metal left to obtain one more big blade, and I cut it to resemble a pointy chef's knife. A 10in circular blade is not big enough to get a decent tang, so I left a 2in section planning to weld some leftover steel (from the cracked santoku) to complete the tang. Attempts to arc weld some samples ended in disaster and finally the tang extension was welded in by some professional in a metal shop. The guy did a nice job and charged something like 6 bucks for it.
Now, I had to face the HT challenge. This time I knew SKS5 has to be quenched in oil. I also knew that SKS5 is an eutectoid steel which resembles L6 (with a somewhat lower alloy content), so the magnet test for austenization should be ok. In any case, I tested a small sample, heating it to red with a propane torch and quenching it into a cup of used motor oil. Before I could finish putting the torch back in its place, my dad grabbed the sample, put it on a piece of railroad track and hit it with a hammer to see if it was brittle. The steel shattered and a flying piece got him a nice cut on his right hand. Sometimes I think I should ground him. To harden the real thing, I built a forge by piling up bricks, and using a pipe with holes as a tuyere and I taped a heat pistol to its end. I was out of charcoal so I had to resort to wood. There were some logs that came from a mulberry tree. Its wood is hard and heavy and produces long lasting embers. I experimented with a piece of scrap metal and a magnet to find out what color the steel should look like. With all ready, it was time to go for the real deal.
I began by normalizing the blade three times. I have no clue if that was good or bad. The ASM heat treater's guide recommends a full anneal before hardening for L6. I could not find detailed information on how to heat treat SKS5, besides the austenization temperature. In any case, I doubt I ruined it. The only problem was that during the first normalization cycle the blade got bent. I managed to straighten it up by pushing it with my index finger when red hot (wearing good gloves, of course). The blade is very thin, 1.4mm (0.055in), which made the operation more challenging. To harden it, I austenized the blade and held it at temperature for about two minutes. I know that for L6 a soaking time of at least 10 min is recommended, but holding the temperature for that long in my primitive forge, while moving the knife to make sure it was evenly heated and making sure I was not bending the blade looked like too much trouble. Also, I'm not sure about how bad decarburization can be, and since the blade is so thin removing a substantial layer of metal is out of the question. I quenched the blade in warm oil (125F). To temper it, I did something I haven't seen online. I put the blade in a tall, narrow can full of hot oil (375F) and kept the temperature there using embers from the forge. I removed the blade from the oil, cleaned it, removed the scale with a belt sander and gave a blue temper to the tang and the top region (near the spine) of the knife. Finally, I redid the oil temper. I'm quite sure the blade hardened, because when I tried to drill a hole trough the tang, next to the ricasso, the bit refused to bite. On the other end (near the butt) the metal was very soft.
I made the handle out of what seemed to be a sledge hammer handle. It was also made of some white wood I have learned to dislike because it screams "I'm dirty". My first go at gluing it ended in disaster, as the 10min epoxy did not give me enough time to get them into position. The rounded shape of the scales made it hard to clamp them, and epoxy acts as a lubricant before it sets. I guess it had a work time of about 2 min. I had to restart the whole process, but before that I got some epoxy with a 1 hour work time. The day after I glued the scales, I sanded the handle into final shape, applied some dye for wood my father had, sealed the ends and applied a 3 layers of Petrilac. The final result is this:
If you wonder why the writing is upside down, that is because cutting the blade that way gave a bigger knife. The smeared cyanocrylate shows a lot. I could use sandpaper to remove a thin layer of surface and give the handle a neat finish, but I will let it be. The blade is not 100% straight, as a result of the bending during normalization, which I guess is hard to fully correct using only your index finger. At least I did not have to use a ton of epoxy to fill the gap between the scales and the tang. However, I'm afraid I used lot of pressure when clamping the whole thing but I run into some nice tutorial by Mr Stacy Apelt after the knife was done.
I had put a rough bevel, guesstimating the angle, before heat treatment. Then I had to form the edge by hand. Vacation time was over, and I had to fly back home. I finished the blade putting a 15 deg bevel on both sides and a 20-ish deg microbevel. To obtain the 15 angle I used my "rig" which is nothing but a portable, inclined plane made out of eco-friendly cardboard. I have an adjustable, wooden version now.
I put some cheap aluminum oxide stone there. The inclination is 15 deg, so I just need to keep the knife flat to get a 15 deg sharpening angle. It is way easier to be consistent at estimating 0 deg than 15 deg. After some interesting number of hours I managed to get it "well enough." It doesn't look so nice near the heel, but I needed to move on with life. I gave it the final edge using my King waterstone. Cuts nicely, although I haven't figured out how good the edge retention is. What I am happy with, is that the handle is comfortable, and the knife is properly balanced (CG at the bolster). That's good when you use the chef's pinch. It is a light knife, I wish the steel had been thicker. It is lighter than my Forschner 8" chef's knife but heavier than the 8" fine edge pro.
So that was the story. Now I have three more knives in the pipeline, lots of things to try out and many more to learn. I will be fun.
First post here, to introduce myself. I also writing with an altruistic purpose. I've seen here a handful of first knives here that look absolutely amazing. As those can be most intimidating to prospective knife-makers, I feel it is my duty to show what a mere mortal accomplishes when he does not try hard enough and he neglects too much good advice.
For some of the more experienced, maybe this may help you to remember that first experience and laugh.I got interested in knifemaking last year. I like cooking, but after about 25 years of being an enthusiastic amateur, the best piece of cutlery I had was this http://cdn.norecipes.com/wp-content/uploads/2009/09/knives-41.jpg. It was ultra dull after years of NEVER sharpening it. I just used a steel, thinking it was good enough. I decided to fix the problem by buying a set of decent, affordable knives and some sharpening system. I went online and discovered that "choosing a knife is harder than choosing a digital camera," as someone accurately described. I settled for some Forscher knives and a Japanese waterstone. Then I was reading a lot about how to sharpen a knife, which lead me to learn about the different kind of steels, and the heat treatment procedures. Soon I was reading about knifemaking and I was hooked. I never cared much for hobbies of this kind but I had to have a go at it.
I cannot make knives at home because I live in a 1 bedroom apartment, but my dad has a small farm, and there he has a shop with a number of power tools he uses mostly to maintain the heavy machinery. He also used to make furniture for fun. On top of that, he is retired, which means he has time to fool around with a project like this. I thought it was going to be a nice way to spend some time with him, and I was right. As soon as I emailed him about the project he was off to buy some old circular saw blade. He got a 10" one, of unknown purpose and origin for $3. No one can blame him for lack of enthusiasm.
Meanwhile, I was thinking that, maybe, a baby step approach was wiser. Wouldn't it be easier if we started from a knife to get a knife? Maybe restoring a beaten up one was the way to go. I remembered the "big, good knife" my mom used in the kitchen when I was a kid, and I remembered seeing that knife sitting in a drawer for years. I emailed asking about it and dad said he had being using that knife to cut aluminum/asphalt membranes when fixing the roof. He sent me the picture of what was left of it. The peculiar blade shape is a consequence of years of my dad's overeager approach to sharpening using the grinder. So this was the plan: Recover as much as possible of the old knife and get a few blades from the circular saw blade.
I threw the old knife blade into a bonfire to anneal it (or whatever would happen to the mystery steel), and while waiting for the logs to consume, I asked mom about the knife and how she got it. She answered "your grandmother bought it when she was 22, right after she got married." I felt as if I had thrown a 75 year old family relic into the fire. The next day, I straightened the blade as it has curled up a lot. With some help from my brother in law, AKA Bichi, I profiled the blade using an angle grinder. I removed the badly corroded tang section and Bichi was kind enough to arc weld a piece of mild steel to replace it. He has a small shop were he makes skid plates for motorcycles, so he has some interesting tools there.
Then came the time for the first heat treatment. My dad talked me into using the living room salamander stove as a forge, using a combination of charcoal and a propane torch for heating. I did not liked the idea of deviating so much from conventional protocols but it certainly saved time. Now, plunging red hot steel into a bucket of used motor oil from the bulldozer in your living room sounds like a bad idea simply because it is. Luckily for us, mom was not at home that weekend. The blade of that knife is so thin that I used two thin plates of mild steel to improvise a scaffold to prevent warping. We heated it up until it looked cherry red to us, soaked it for like two minutes and quenched it. I guessed it worked, because the blade hardened and was still straight. I tempered it in the kitchen oven (no thermometer, of course), for 1 hour. Here is a picture of the blade after HT and some sanding. Note how the mild steel melted while welding it, forming a hole.
I made the scales out of a hammer handle. It's some white wood, with very even and faint grain. Mystery wood should go well with mystery steel. I epoxied it, used cyanocrylate to seal the ends and I used some wood finish product on it (Petrilac) http://www.petrilac.com.ar/eng/producto.php?producto=16&uso_linea=linea&uso=. Here is what it looks like (I repolished the blade for the picture only, I will force a patina at some point).
I made it months ago so it is a bit dirty by now, but is not that it looked much better when it was new. Fit and finish is definitely sub-standard. The tang piece was warped and the thickness of the mild steel addition did not match the original blade's.
I sharpened it with my waterstone (that I can do reasonably well) until shaving sharp. The tip seems to be softer than the rest of the edge. Maybe a defect of HT. Maybe the blade was so thin (the spine is about 0.055in thick and the blade is tapered) that the tip cooled down before getting into the quenchant?
It is very basic and not terribly well executed, but it is usable.
The same day we filled the living room with burnt oil smoke, we also HTed two blades that came from the circular saw blade. For the sake of science, we used water as quenchant and both blades cracked. One of the blades was an approximation to a santoku. It didn't just crack, it bent in a funny way, much like a spherical sector.
It was time for a more scientific approach. I googled for whatever was written on the blade. It turned out to be a bush cutting blade, made out of SKS5. There was enough metal left to obtain one more big blade, and I cut it to resemble a pointy chef's knife. A 10in circular blade is not big enough to get a decent tang, so I left a 2in section planning to weld some leftover steel (from the cracked santoku) to complete the tang. Attempts to arc weld some samples ended in disaster and finally the tang extension was welded in by some professional in a metal shop. The guy did a nice job and charged something like 6 bucks for it.
Now, I had to face the HT challenge. This time I knew SKS5 has to be quenched in oil. I also knew that SKS5 is an eutectoid steel which resembles L6 (with a somewhat lower alloy content), so the magnet test for austenization should be ok. In any case, I tested a small sample, heating it to red with a propane torch and quenching it into a cup of used motor oil. Before I could finish putting the torch back in its place, my dad grabbed the sample, put it on a piece of railroad track and hit it with a hammer to see if it was brittle. The steel shattered and a flying piece got him a nice cut on his right hand. Sometimes I think I should ground him. To harden the real thing, I built a forge by piling up bricks, and using a pipe with holes as a tuyere and I taped a heat pistol to its end. I was out of charcoal so I had to resort to wood. There were some logs that came from a mulberry tree. Its wood is hard and heavy and produces long lasting embers. I experimented with a piece of scrap metal and a magnet to find out what color the steel should look like. With all ready, it was time to go for the real deal.
I began by normalizing the blade three times. I have no clue if that was good or bad. The ASM heat treater's guide recommends a full anneal before hardening for L6. I could not find detailed information on how to heat treat SKS5, besides the austenization temperature. In any case, I doubt I ruined it. The only problem was that during the first normalization cycle the blade got bent. I managed to straighten it up by pushing it with my index finger when red hot (wearing good gloves, of course). The blade is very thin, 1.4mm (0.055in), which made the operation more challenging. To harden it, I austenized the blade and held it at temperature for about two minutes. I know that for L6 a soaking time of at least 10 min is recommended, but holding the temperature for that long in my primitive forge, while moving the knife to make sure it was evenly heated and making sure I was not bending the blade looked like too much trouble. Also, I'm not sure about how bad decarburization can be, and since the blade is so thin removing a substantial layer of metal is out of the question. I quenched the blade in warm oil (125F). To temper it, I did something I haven't seen online. I put the blade in a tall, narrow can full of hot oil (375F) and kept the temperature there using embers from the forge. I removed the blade from the oil, cleaned it, removed the scale with a belt sander and gave a blue temper to the tang and the top region (near the spine) of the knife. Finally, I redid the oil temper. I'm quite sure the blade hardened, because when I tried to drill a hole trough the tang, next to the ricasso, the bit refused to bite. On the other end (near the butt) the metal was very soft.
I made the handle out of what seemed to be a sledge hammer handle. It was also made of some white wood I have learned to dislike because it screams "I'm dirty". My first go at gluing it ended in disaster, as the 10min epoxy did not give me enough time to get them into position. The rounded shape of the scales made it hard to clamp them, and epoxy acts as a lubricant before it sets. I guess it had a work time of about 2 min. I had to restart the whole process, but before that I got some epoxy with a 1 hour work time. The day after I glued the scales, I sanded the handle into final shape, applied some dye for wood my father had, sealed the ends and applied a 3 layers of Petrilac. The final result is this:
If you wonder why the writing is upside down, that is because cutting the blade that way gave a bigger knife. The smeared cyanocrylate shows a lot. I could use sandpaper to remove a thin layer of surface and give the handle a neat finish, but I will let it be. The blade is not 100% straight, as a result of the bending during normalization, which I guess is hard to fully correct using only your index finger. At least I did not have to use a ton of epoxy to fill the gap between the scales and the tang. However, I'm afraid I used lot of pressure when clamping the whole thing but I run into some nice tutorial by Mr Stacy Apelt after the knife was done.
I had put a rough bevel, guesstimating the angle, before heat treatment. Then I had to form the edge by hand. Vacation time was over, and I had to fly back home. I finished the blade putting a 15 deg bevel on both sides and a 20-ish deg microbevel. To obtain the 15 angle I used my "rig" which is nothing but a portable, inclined plane made out of eco-friendly cardboard. I have an adjustable, wooden version now.
I put some cheap aluminum oxide stone there. The inclination is 15 deg, so I just need to keep the knife flat to get a 15 deg sharpening angle. It is way easier to be consistent at estimating 0 deg than 15 deg. After some interesting number of hours I managed to get it "well enough." It doesn't look so nice near the heel, but I needed to move on with life
. I gave it the final edge using my King waterstone. Cuts nicely, although I haven't figured out how good the edge retention is. What I am happy with, is that the handle is comfortable, and the knife is properly balanced (CG at the bolster). That's good when you use the chef's pinch. It is a light knife, I wish the steel had been thicker. It is lighter than my Forschner 8" chef's knife but heavier than the 8" fine edge pro. So that was the story. Now I have three more knives in the pipeline, lots of things to try out and many more to learn. I will be fun.
