Saturday, May 7, 2011

My Final Project: Part VI

I'll let the picture speak for themselves. My first piece, of which I'm proud; a token of my learning:

My Final Project: Part V

Here is the blade in its final stage before hilting:

Here is one side carved with Ringerike-style Norse ornament and the finished bolster:

Here is the other side with a less abstract design:

The bolster looks beautiful thanks to file-work and 400 grit sandpaper!

Here she is, all assembled! The end bolster is buffed sheet copper held on by four brass tacks and a cold-peened tang!

My Final Project: Part IV

My camera battery was dead while I was making my handle, so I'll have to describe it. I found a great piece of tiger maple just the right size. I squared all the sides of it and marked the centers of the ends, and drilled a small hole all the way through it, from both ends. This was to be the pathway for my first attempt at burning a hole into the handle. The way this is done is heating the end of the blade's tang to a red heat, and forcing it through the pilot hole. Smoke comes out and it burns the shape of the tang, but it takes many, many heats, and one must be very careful to hold it perfectly straight or it may go off course. I think this may have happened to me, and it was a time-consuming and somewhat frustrating process, but I was pleased with the experience.

Next time, I know to make the tang more gradual in its taper, heat the blade up hotter, and drill a bigger hole, rather than make it too small like I did, which allowed for some wandering of the hot tang in the handle and a crack in the wood when I pushed it too far.

Next, I made the bronze bolster for the bottom (blade end) of the handle. I found a piece just the right size and drilled holes the size of the blade. I drilled much bigger holes on the back so the only sawing and filing I would have to do would be on a smaller thickness, and there would be more space for the glue to expand when I glued the bolster on. Here I am with the forever-breaking jeweler's saw:

Here is my bolster laid out:

After that was finished, I used my new knot-drawing and carving skills!

Maple is much nicer to carve than the walnut I've experience previously. It's harder, but far far less rippy, and could have looked extremely nice if I'd had the time with it. Unfortunately, I could only carve roughly and the finishing wasn't complete! It looks authentic though, if not the absolute best of my ability.

My Final Project: Part III

I was unable to take pictures of it, but the next step of the heat-treatment was tempering. Tempering is converting some or all of the rigid, brittle molecular structure of the hardened blade into another that is much more durable and flexible, but retains the hardness. This is achieved by heating the metal up again to another critical temperature, keeping it at that heat for an amount of time, and then cooling it very slowly to room temperature. The file I happened to have is most likely made out of 1075 carbon steel, and its critical temperature is somewhere around 475-500 degrees Fahrenheit. I wrapped it in tinfoil so it would heat evenly and stuck it in my dorm lounge oven for about an hour when the oven reached that heat. Then I turned the oven off and allowed it to cool completely. When I took the blade out, I could bend it both ways up to maybe 25 degrees and returned absolutely true. It was now a true blade.

The next step was making a tool with which to scrape the decorative grooves I wanted based on historical examples. I learned about this tool on Don Fogg's very helpful bladesmithing site, and I made my own version by drilling and tapping a hole to screw in a carbide lathe bit, welding on a stabilizer, and drilling holes for an adjustable fence, which I had to screw on using a square to make sure it was, you know, square.

Then I custom-cut a piece of wood to clamp the blade on, with one edge in the exact shape of the groove I wanted to score. I calculated the placement of the blade and began scraping!

It worked surprisingly fast! I had four grooves to carve, two on each side meeting on a point, and I did the whole thing in less than an hour.

On the last groove it was getting late and I was tired, but I wanted to finish this step. I paid for my impatience by slipping with the tool and scraping parts of the blade I didn't want to, resulting in scratches that are still there. But overall it worked quite well, and I won't do that next time!

My Final Project: Part II

Heat-treating has two parts: hardening and tempering. Hardening occurs when the blade is brought to a critical temperature (depending on the type of steel) and then quenched in a liquid in order to cool it quickly and form a rigid molecular structure. I was going to quench my blade in oil, which would cool it slightly slower than water in order to reduce risk of cracking or warping, but still fast enough to result in desired hardness. So, I made this quench bath by TIG welding some tube to a 1/4" steel base and filling it with canola oil.

The only certain ways of knowing whether a blade is at critical temperature are color and magnetism. Once the blade is no longer magnetic, the molecules are ready to form their rigid structure in the quench.

Due to the thinness of the blade, I had to correct many warps occurring from gravitational bending while holding it in the forge to heat it up. I learned that I had to rotate it often, as well as drawing it in and out to heat the blade evenly. Most of the process of forging a blade looks like this anyways:

When it was evenly heated to nonmagnetism, I plunged it into the bath amid a gout of flame! I had to be careful that it was pointing straight down and that I did not move it from side to side in the bath, as these would invite warping because of the uneven hardening of sides, like the warping of my shield with the glue. It also helped that I put a hot poker in the oil beforehand to heat it preliminarily; ideally, the oil is hot to provide for less shock in the quench, like using oil instead of water. Just another precaution.

After the blade was cool, I drew it out of the quench bath and scraped it with a file to see how hard it was. I couldn't make a mark!