Making a Rondel Dagger – Part 4 – Hardening

Today, after finishing with my bonsai trees for now, I got an hour or so to use and get a shot at hardening the blade.

I was so stressed from working almost non-stop the whole weekend and trying to manage to replant all my outdoor bonsai trees that I forgot to take pictures of the process and only could take pictures afterwards. So here is a picture of my setup. I was hardening two blades.

Blade hardening setup

Blade hardening setup.

Slight  contrast with Marcus’s fully equipped workshop I guess :-). On the right is gas mini-forge where a future kitchen knife was heated up most of the time, on the left is a charcoal fire between fireclay bricks for the dagger and in the middle is quenching oil. This is the main reason why I cannot harden blades in bad weather – I have to go outside to do it.

And here are the blades after hardening and before tempering, covered in burned oil and, in the case of the dagger, slag and scale.

Blades after quench.

Blades after quench.

I am not all together sure It was a complete success. I am sure it was a 50% success. I definitively successfully hardened the kitchen knife. Which is slightly strange, because the kitchen knife is made from N690 steel that is allegedly difficult to harden in impromptu settings, whereas the dagger is simple carbon steel that should have been easy-peasy. The kitchen knife is completely without deformation, the dagger got a very slight bend that I was able to correct after tempering the blades in kitchen oven at 150°C for an hour. In fact, it was maybe too easy to correct. File skids on the kitchen blade like on glass, but it is possible to make a shallow bite with it into the dagger.

The problem might be that I tried to coat the dagger with an experimental anti-scaling solution that unfortunately did not work as intended. Back to the drawing board there I guess. So it might be that the blade is hardened, but a few tenths of a mm on the surface have slightly lowered  carbon content due to decarburization. The N690 steel blade was not covered in the solution, but was covered with stainless steel foil that burned through towards the end.

I have no way to measure the hardness of the steel, and I am probably not going and try to re-harden the blade. I will proceed and we will see what comes out of it.

Making a Rondel Dagger – Part 3

All of my garden has woken up, but none of the figs or pomegranates have shown even a budding leaf. I got so disheartened at this that I had to go and do something fun. So I went to work on the dagger to lift my spirits at least slightly.

I have decided to grind the bevel higher up to the spine, but not the same way along the whole blade – I ground less towards the tip so it remains strong. This has meant that the blade has a bit complex geometry which meant I could use hard belt most of the way, but I had to switch to slack belt for the tip. Luckily I have kept the option of half hard/half slack belt setup on my improved grinder.

I also ground the spine at approximately 45° angle to take off some weight. But again not all the way to the tip, so the tip is reinforced.

After I ground this basic shape It took me about an hour to get through four ceramics belts (60, 80, 100, 120) and the final was a zircon 120 grit where I stopped. This is actually a fairly difficult and delicate process and it is still possible (nay – easy) to mess up the lines and irreparably ruin the blade geometry, so easy does it. Because I am not too experienced with the belt grinder yet I had a few heart-stopping moments, but I managed to correct all the blunders in the end. From my previous works I know I have to be extremely careful up to approx 600 grit. After that messing up the lines in hand is not possible. But on my previous dagger I found out that on belt grinder that level moves up to 1000 grit, possibly 1200.

A lot of eyeballing was involved. After certain point I could no longer use the masking blue color and scribing tool, so to check whether my grind is symmetrical I used a folded piece of paper that I cut with shears to two aligning points. When I folded it around the blade  I could see whether the lines are in the same position by putting the point on one side of the blade  on the line and checking the point at the other side. After the final grind I scrubbed the blade lengthwise a bit with coarse abrasive pad to remove the quickly building rust and to scratch through the grind marks.

Ground blade shape.

©Charly, all rights reserved.

The future cutting edge is now approx 1 mm thick. Next step will be hardening the steel. For this I had to check whether this file was carbon steel throughout or case hardened. That I have done before polishing the whole shape by dabbing the spine and one side of the blade approx 5 cm from the tip with  ferric chloride because in this area is preserved steel that was near the surface of the original  file as well as steel that was deep inside. If the file was case hardened, the steel that was originally near surface should turn grey, while the steel that was deeper should be shinier. If the file is carbon steel throughout, it should all turn grey.

It has all turned monotone grey, so it is carbon steel throughout. That is good since it makes the hardening process easier. It is possible to make a cutting blade from case hardened file, but it requires to perform again case hardening, which takes more time and resources.

Making a Rondel Dagger – Part 2

Today I planted new cherry tree but there was not much that I could otherwise meaningfully do, so I have spent about 40 minutes testing my belt grinder. It has worked reasonably well, but the supporting table needs improvement.

I chose this particular file for this project because it is thick at the base – almost 6 mm – and it already had a distal taper. That means I do not need to grind of as much material, but it is actually more challenging to work with, and therefore better exercise.

Centerline for he edge.

Centerline for the edge.

First problem was scribing the center line for where the edge shall be. Due to the taper I could not use my scribing tool because it scribes line at a constant distance from an edge. Luckily the curvature is very mild, so I could do with a steel ruler for most of the way and steady(ish) hand for the rest. I am not fond of measuring, I prefer to eyball the work, but for blade symmetry is important. The more asymmetrical the roughed out blade, the more it warps in quench. Very slight warp can be ground off, but big warp not. And of course grinding off a warp on hardened blade is tougher on the abrasive belts, and those do not grow on trees.

 

 

Scribed bevel lines.

Scribed bevel lines.

After scribing the center line, I also scribed two lines for where the bevels shall go. This dagger will have only one cutting edge, and in order to make it more useful as an ordinary knife, the bevel should go almost all the way to the spine at first grind, and wander de-facto all the way to it during polishing. On the other hand shallower bevel is easier to make and makes for stiffer blade. At this point I have not decided on the way I will do it. I scribed two bevel lines and decided to grind to the first one and reconsider.

With these preparations done, which took only about five minutes, I have spanned a 60 grit belt on my grinder and started. First time I was grinding with the use of supporting table and it was a great help at first and slight hindrance later on. For me it might be good to use the table for first facing and then go back to free-hand. I am slowly finding my personal way of doing these things. After slightly over half an hour I ground both sides to the first bevel line and had to call it quits for the day. Now I am considering my next step. Grind or not to grind, that is the question.

Ground bevels

©Charly, all rights reserved.

Making a Rondel Dagger – Part 1

When the weather is not suitable for work outside, I will make use of my belt grinder, now  Mark 2. So today I took another old file and I decided to make a dagger out of it. The inspiration is dagger used by Vesemir and Ciri in the game Witcher 3, but there will be some design changes even for the blade (less daggery, more knifey). I will post my progress, but beware that I am no expert, just a self-taught hobbyist goofing around. Risk of concussions from facepalming for any expert. You have been warned.

I started with an old file that I threw in the stove fire last year to soften the steel. I cleaned some of the rust on the belt grinder when I was testing the new design. But before proceeding I needed to make the tang slightly longer. So today I just made the tang more pointy and chamfered the edges. Then I took an old piece of round stock of structural steel, cut it lengthwise for a few cm and fitted it onto the file tang.

 

Old rusty file

Old rusty file

Chamfered file tang

Chamfered file tang

Fitted tang extension

Fitted tang extension

After that there came the trial by fire, or more precisely, electric arc. My first real welding. I admit I should have tried to simply weld scraps together a few more times before I try for something real. I should have. But learning skill on something that is subsequently thrown away simply is not me. I always try to learn on the real thing. Not smart, I know, but that is just me. I have already forced my self to try it once on scraps.

I must admit, I could not have done a better job. That is to say, the job is crap, but I lack the skill to do better. But it holds together even after grinding off the slag and rust from the whole thing. There are some visible slag inclusions in the weld, but it is definitively welded together and since it will all be hidden in the handle, I will not lose sleep over it. Hopefully no rampaging rhino will stamp on it and ruin it all.

Welded tang extension

Welded tang extension with slag.

File cleaned.

Cleaned and the tang ground to rough shape.

With that done I finally could do some work on the belt grinder. Since I do not have machinist’s blue, I used 1 cm thick blue marker to cover one side of the file. Then I have drawn the center line  and quarter marks using a steel ruler and a self-made steel marking needle. After that I ground the file into a symmetrical leaf shape. With that I was done for the evening and I will resume the work at some other random date.

ground basic blade outline

©Charly, all rights reserved.

There Is Such Thing as Too Much “Weapons” Regulation

Over the years I have expressed in multiple comments under various articles on FTB that whilst strict regulations of access to weapons are necessary, the strength of the regulations should be proportional to how effectively enforced they can be. Regulating automatic guns makes sense because they are difficult to manufacture and conceal. That makes it possible to effectively limit access to them and enforce the regulation in a meaningful way.

On the other hand I have always seen trying to regulate knives, swords and similar as absurd because such regulations just cannot work as intended. Making a functional knife or even a sword is trivial, all you need is a piece of cord, a flat bar of any type of steel whatsoever, and half an hour work with angle grinder. Sure, it will not be beautiful, and if the steel is crap it will not hold an edge, but that does not matter, it will be effective murder weapon of equal quality to what was used most of history in warfare. And concealing a knife on your body under clothing is trivial.

UK has nevertheless decided to pass such a meaningless regulation:

Luckily I am not living in UK and CZ has not jumped the shark yet and knives are completely unregulated here. But should such laws pass here, I could perhaps get into problems when trying to buy certain tools for my hobbies – for example I intend to work with leather at some future date and for that I will need to either buy or make a few specialized cutting instruments, aka knives. I live in rural area and I definitively have no corner shop around that could supply those things on demand.

I feel sorry for all the antique weapons dealers and all the knifemakers in UK – like the excellent Tod Todeschini, whose carefully build livelihoods can be destroyed in an instant with ham-fisted regulation.

I might add that to my knowledge this regulation has been proposed and written by conservative politicians. Similarly like the US knife regulations, which are stricter than firearms regulations in some states, were too written by conservatives. Laws that are either impossible to effectively enforce or are impossible not to break serve no other purpose than to give police a pretense to for example harass people of inconvenient shade of skin at will, nothing more.

And just for “fun” (which is not funny at all) I will list all the object that could be used as murder weapons and are in my line of sight right now, near my computer:

  1. Stabbing – screwdrivers, shears, pencils, ball-pens and admittedly a dagger that I use as letter opener.
  2. Cutting – a carpet cutter and again my dagger.
  3. Garotting – USB cable seems strong enough and definitively the camera strap.
  4. Blunt instruments – the camera (not the first choice of course), two heavy mugs, two ornamental stones, a few potted plants.

Not to mention the about 8 kitchen knives of various sizes on the kitchen counter behind my left shoulder.

If I were to go to my workshop or my garden shed I would have a wide choice of multiple potential cutting or stabbing weapons, blunt instruments and pole-arms. Should I decide to go and join a gang, I would not be unarmed. Indeed I could arm the whole gang. So could each of my neighbours.

Whilst firearm deaths can be linked to firearms availability, stabbing deaths cannot be linked to knives availability. Because stabbing instruments are everywhere and will be everywhere, always. As Sam Vimes’ maxim states “Everything is a weapon if you decide to think of it as such”. Addressing knife crime needs to address the root cause. And I do not think I am stabbing in the dark here when I say that has more to do with impoverishment and disempowerment than with sending knives per post.

Sharp and Shiny.

From Charly: This is the knife I have given to my Mom for Christmas. Scary sharp – I could slice that tomato paper thin. Seems to hold edge well, it was already used since I made it and the edge was not touched up prior to photographing.

Measurements: Overall length ~26 cm, blade ~14 cm lenght, ~2 mm thick, blade grind convex with no secondary bevel.

Materials: handle scales chemically treated Elder wood (Sambucus nigra) coated with PU, blade N690 steel hardened at home in impromptu settings.

I hope to improve the design based on my mothers feedback and make more knives like this one in the future, it was fun. Beautiful! Click for full size.

© Charly, all rights reserved.

Pointy!

From Charly, who I think is being much too modest:

This is the first knife I have made with the help of my out-of-scraps built belt sander and my drill powered lathe. Because this was a learning exercise for me, I took a bunch of old worthless stuff – a rusty file, rusty pipe, some old hinges, broken furniture legs and a piece of cow bone dug out of the ground in the garden. I have also deliberately used only the machines to do most of the work, including polishing – I wanted to see what kind of fit and finish I will be able to get this way.

Because it was learning exercise and because the materials were of bad quality (the pipes were a bit too rusty, I sanded through them at a few places) the result is not something too great, but it is sharp, pointy and dangerous. The design is a sort of hybrid between the Fairbarn-Sykes and a medieval rondel dagger and I freehanded most of it, with almost no measurements.

Stats: overall lenght 33,5 cm, blade length 22 cm, work time approx 12 hours (not including curing of the paint)

I am not intending to stab anyone, but it is extremely good letter opener. Click for full size!

© Charly, all rights reserved.