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Jeff Amundson

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Everything posted by Jeff Amundson

  1. You want complete? I thought I could let people imagine their own bows. Actually, it was lunch time. I can finish the hot work to be true to the post's title. I've got about 1 1/2 hours into this, with many more to go. The grinding, finishing, and assembly work don't belong in this thread. Thanks for the compliment.
  2. First I fuller vertically to divide the blade from the shank. The tooling is mounted in a treadle hammer. The steel is 1018 CRS, 516" X 5/8". Next I weld the cutting edge - 1075, 5/32" x 5/16". It took me a while to get used to putting the cutting edge on top like this. It looks wrong if you're thinking knives. The weld is blended in and forged back to the original dimensions. This is a combination of hand forging and power hammer. The shank is drawn out square. The horizontal fuller is the tricky one. It provides a thickness target for subsequent forging and grinding. It also provides some clearance in the pivot area. I have to eyeball its location relative to the first fuller. This is on the treadle hammer again. I have to take it slowly, because the little humps sticking out the sides of the bar get real big if I don't correct it often. Next I draw the blades out to uniform thickness. This is done on the flat dies of a power hammer, taking little bites at a time so the blade grows in length but not much in width. There's plenty of hand forging to keep the cutting edge straight. As I approach the final thickness, I focus on flat and straight. It makes for easier grinding. The last forging will be to draw out the shanks and bows.
  3. I made this in bronze because it lives in Hawaii. I forged it using silicon bronze, C655, which is 97% copper and 3% silicon. It crumbled if forged too hot. I would heat it medium red (best in a dark room), set it on the anvil for a few seconds, and then it would forge beautifully. It forges cold, too, until it work hardens. Heat and repeat.
  4. Got out the diamond stone to see how well I did at the grinder.
  5. At the time I wrote that, 'some' meant 'a few'. I hadn't yet read a wonderful little book titled "Knives and Scabbards" by Cowgill, de Neergaard and Griffiths. It's a detailed study of medieval knives, shears and scissors found in garbage dumps near London. It turns out my butt weld technique would be right at home in the 13th century. Most of the blades analyzed were wrought iron with a steeled edge. I took Alan's advice and have been using 1075 on the edge. The picture shows blades of 1018/1075 after they were drawn to half the original thickness. The two alloys moved about the same amount. I'm also more careful to work at high heats. I used to do some straightening at lower heats, but I can see how that created shear along the weld. I now take a heat to straighten as well as to forge.
  6. Progress on two pairs of scissors. Next is drawing out both blade and handle ends. I normally work one pair at a time, because working two blades means I rarely stand around waiting for something to heat up.
  7. The mystery wood looks like impreg to me. Impreg is an early version (mid 20th century) of stabilized wood, usually with a phenolic resin impregnating a laminate in a vacuum. A higher density version called compreg was produced under high pressure on the laminate. The smell was probably the phenolic.
  8. Thanks, Aiden. That means a lot. My second career was as manufacturing engineer in a bicycle factory. The president of our company once pulled me out of a design brainstorming session because any talk of manufacturing capabilities would 'stifle the designers' creativity'. I can't think of a design without thinking about its process, so form and function are a blur in my mind. Thanks for the compliment, Dick. I started grinding knives ala Bob Loveless in the early '80s. I took up blacksmithing about 2000. Many blacksmiths hate grinding, and many bladesmiths are not great blacksmiths. Forging and grinding scissors requires skills in both. I agree. My complaint is that the internet failed to connect me with other people doing something similar. I want to have discussions about screws and grind angles and heat treats, which is my hope for the Bladesmith's Forum.
  9. Thanks guys. I was shocked when the internet failed me. I thought I was just looking in the wrong places, so I joined Instagram. There are a few people forging scissors occasionally, but they are often doing it as a sideshow. I'm 72. In my first career, I taught public school industrial arts for 10 years. I've been making stuff all my life. I have never before experienced the reaction I get when I tell people I make scissors. The predictable reaction is a jaw-drop along with a statement of disbelief. People just can't comprehend the idea of an actual person making a pair of scissors. Scissors come from factories, so they look at what I do with suspicion. Many ask “do they work?” I've never seen anything like it. The scissors cabal has brainwashed us all! That's why I had to purge closed-die thinking.
  10. Here's my latest design using as-forged shanks and bows. The round cross-section is easy on the fingers. I shape the bows on a mandrel, so I can change the size and shape to fit. The long tail that forms the wrap is a little tedious to forge. Since it ends up under 1/8” diameter, it's like forging wire. As a dedicated hobbyist, I've lurked on this and other forums for years. I never felt qualified to comment on much of anything. When I started playing with scissors, I expected to find inspiration and ideas to steal online. I found next to nothing to help me. I now find myself in the position of trying to inspire others. I don't claim to be expert at much more than my own experience of one pandemic's worth of scissors experiments. One fact I can report about scissors making is that it requires many discrete steps. Doing things in the right order is big deal, and I'm constantly revising what comes first. A big part of my development has been getting the sequence right. This design was driven by one of the last steps in the process – aligning the blade tips when the handles are closed. The goal is to have the scissors cut all the way to the tip, which means the tips have to cross ever so slightly. I bend those tails that meet in the middle to adjust how the tips meet. I can do this with a torch and pliers, no hammer required. The shanks and bows themselves are not involved in this adjustment, which is a good thing. This adjustment is necessary because the blades are hand forged. That represents another of my many learning curves – purging closed-die thinking from my designs. I'll save that for another post.
  11. My industrial experience was with epoxy-bonded aluminum bicycle frames. The prescribed bond prep was to blast with aluminum oxide grit followed by rinsing with isopropyl alcohol, no exceptions, no substitutes.
  12. Thanks Alan. I don't think Grace forges. As far as historical practice, I've seen scissors produced both ways. I learned the butt weld because my first scissors were little one-piece spring shears, and they are made that way. I bought one an Amazon and reverse engineered it. When I started to make pivoted scissors, I decided to see if I could scale up the technique. It seemed to work, and I've since seen some historical examples. I've seen videos of scissors produced with the flatwise laminate you described. I haven't been tempted to try it, because I don't know what I'd gain by it, except maybe some warpage issues I don't have now. I'm not worried about having the ends uneven after forging. They get ground off anyway. I'm just want to reduce the shearing effect on the weld. I think I have to do that with heat, not alloy selection. Thanks. That's what I was wondering - if alloy selection would make my forging technique a little less critical. And thanks for providing a forum for this discussion.
  13. My method of making a scissors blade is to forge weld a tool steel cutting edge to a 1018 body. I've tried a few different tool steel alloys, but I'd like some expert opinions to help me optimize my choice. This photo shows how the tool steel sits on the 1018 for welding. The forged blade (that I pulled from my scrap pile) shows how the blade is drawn out. I forge to thickness, not length. The blade starts 5/16 thick, and I forge it to 5/32, which about doubles its length. I've used 01, 1084, and 5160. I have two main criteria I'm trying to consider in alloy selection. The first is the alloy's tendency to air harden. I work in thin sections that don't hold heat long, so I want to avoid an alloy that's prone to air hardening. The second criteria is demonstrated in this photo. The mild steel moves easier, so it squeezes out the end. That creates a shear along the weld line. I know if I work only at high heat, both these issues are minimized with any alloy. I'm trying to optimize, so I want to know if there are differences, especially with the air hardening. Anybody have opinions on alloys in this application? I have an Evenheat oven and a couple different quenchants, so the heat treat requirements aren't a factor in my choice. Thanks for your comments.
  14. There's no scarf in these pictures. I think you're looking at how the O1 broke. I scarf the butt end of the O1 where I have to blend it into the 1018, but that's not in these pictures.
  15. I think I know what's going on here, but I'd to hear other opinions. This scissors blade was an experiment to begin with. When I found some cracks, I decided to break it to see what was revealed. The first picture shows the tip end of the blade. It's a heat treated laminate of 1018 and O1. I used a little ferric chloride to clearly show the two alloys. I sawed and ground the 1018 to remove it from a short section. Then I clamped the exposed stub of O1 in a vise and tried to create a peel in the weld. The O1 eventually broke. I was happy how far the O1 bent before breaking. Even though the weld looks flawed, it resisted the peeling force. I was also happy with the look of the grain in the break. Note: the dark black stain on the broken section is from the ferric. I'm guessing the O1 cracks are from forging it too cold. I was already planning to stop using O1, so the cracks helped me make the change faster. I know O1 can air harden, and I think I crossed the line with it. Looking forward to comments.
  16. Not at this stage. I forge them as flat as I can. Adjusting the blade overlap is one of the last steps. We follow each other on Instagram. She's been a great help.
  17. Today I tried drilling the pivot hole before doing any grinding. It's the first time I've done it this way. I need the pivot screw in place to finish the hot work, but I don't like cleaning the scale off multiple times. The forgings need to fit together as forged, but it will let me finish the hot work before touching the grinder. The white mark on the blade is where the tool steel cutting edge ends.
  18. I brought a laser into the smithy and noticed no time warp. It should help me create symmetry around a centerline and locate the pivot hole.
  19. Thanks for all your kind words. I was a knifemaker before I took up blacksmithing. I enjoyed blacksmithing more. Scissors gives me the best combination of both.
  20. I've tried a variety of pivots, both rivets and screws. My first pivoted scissors were bonsai-type, so I used a rivet. Typically these scissors have conical copper or brass washers on the rivet. I initially thought the cone shape was acting like a belleville washer to apply some spring force. What I now understand is that the cone simply lifts the head of the rivet off the scissors blade so peening the head doesn't expand the rivet in the hole in the blade. The rivet is also an axle, so it needs to fit nicely in its hole. Most scissors don't use any spring force to hold the blades together. When wide open, most scissors are a little loose on the pivot. Here is a pair I made and a cross section of the rivet assembly. I pressed flat copper washers into a cone-shape. The rivet head fills the crater at the top of the cone. I prefer using screws for a couple reasons. First, with a rivet I don't know what's moving when I work the scissors. I don't know if both blades spin around the axle or just one does. I don't know if the axle moves in the washers. With a screw I can lock the screw to one of the blades leaving the other blade to spin on the axle. Second, setting the rivet is not a precise process. There's no backing off if it's too tight. Here is a scissors with a screw. I used an 8-32 stainless shoulder screw to test this design, which I copied from a pair of tin snips. I filed a square hole in one blade and a matching square on the screw. The disadvantage of this design is that it requires a lock nut. Then the threads in the nut need to be peened to lock the nut to the screw. While I like how the square hole works, I don't like making it. Lately I've started tapping a thread in one of the blades like a lot of factory scissors do. The screw needs to be locked to that blade by peening after adjustment. This is the screw design I'm currently using. I make it on my lathe from mild steel (I use a die for the thread). The head diameter is 5/16", the shoulder is sized to slip in a 3/16" reamed hole, 8-32 thread. I'm still looking for a good way to peen the screw. I've tried different punch designs on the screw, but I'm thinking I should try to peen the threads in the blade, too. Either way I need to do it without damaging the head of the screw. Which brings me to the design on the head of the screw. I won't use a screw that looks like a screw. I don't want to encourage someone to try to adjust it. I'm going to lock it so it can't move anyway, so I don't want it to look like it can.
  21. I had 2 goals for this design. I wanted to leave the shanks and bows as-forged, and I wanted the scissors to close without having to close my hand. The blades are mild steel with O1 cutting edges and rust blued. I've decided this style - bows created by bending the shanks - makes more sense for my shop than the punched and drifted style I had been making. Scissors have lots of surfaces to finish. This design eliminates the grinding, filing and polishing of the bows. It also lets me easily change the size and shape of the bows. To avoid sharp corners, I forged the shanks round before flattening them. I left the ends round, pushed them through holes punched in the shanks, then flattened the ends. I adjusted how the ends meet to adjust the closing point of the blades. I also tried a new transition between blade and shank. I had been trying to make a 'tight' joint like most factory forged scissors, but I decided it was unnecessary to copy what can be forged in a closed die.
  22. I'm glad to see this post. When I started making scissors a few years ago, the internet failed me. I was surprised and disappointed to find almost nothing to answer my many questions. I'm glad to have someone to learn with. This is the video I studied. The first scissors I made were spring scissors like this. I now make all my scissors this way, with the cutting edge welded on just the edge, not the whole inner face. I will post the bonsai scissors I made.
  23. The first few spring scissors I made went to fly tiers. Easy to pick up and put down. You don't have to wear them.
  24. Thanks Alan. I didn't want to be the one to use the h-word. Thanks, Dan. No, the bend is done cold. The area of the bend is not hardened. I did all the rough grinding before heat treat. I pre-bent it to about 90 degrees for heat treat. That way I can quench both blades at the same time when I pull it out of the oven. I finish grinding the blades in that configuration, sharpen, then finish the bending. The video link I provided shows the bending really well at about 3:00. I aim for a thickness of about .040" to achieve the right springiness. It has to be that same thickness for more than 1" to work right. It's a tricky grind to keep it that thin and even from side to side. I can thin it out more after its bent to adjust the spring.
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