A Custom Knife Progresses

The custom knife I've been making is coming along nicely. I heat treated the blade and did the initial sanding on it. Now comes the making of the handle and attaching it and a hand guard. The first photograph shows the blade after heat treating quenching, and tempering. I used a clay mixture of 1:1:1 of fire clay, #90 sand, and Pozzolana. I cast this mixture and let it cure for 3 to 4 days. A casting fixture is made from wood that is curved to give me a transformed zone of the desired shape. The clay is approximately 3/16ths of an inch thick where I wish the blade to undergo a slower cooling rate.

A Phone App for The Uncommunicative

I don't talk much on my phone and I don't care much for texting either. For some reason my wife would like to hear from me when I'm on the road, or to at least know I'm not dead. I've created this app for my phone so that when I trigger the app she receives an update of my location. I used the MIT App Inventor suite because it was pretty easy to learn and I can build something quickly. Here are the blocks from App Inventor. If I can figure out how to share files on some cloud storage without compromising it some of this stuff will be available for download in the near future. Update: Check the lower right side of the blog.

Off to the High Country

I need some high timber around me. When things take on a bit of a pall for me I know it's time to get away for a few days. Fortunately I have just the thing. Up in the Sierras amongst the tall trees I have a place and it's only an hour drive from the house. The wildlife is prolific, bear, deer, mountain lion, and it's on the Monarch butterfly migration path. They all like the meadow just below me.

Mountain Horse Training

When you're riding the back country, horsemanship follows some different trails. You have to assume nothing will be possible to do in the way you might normally do things. One of these is saddling your horse. Two obstacles immediately come to mind. First, the off side of the horse may be the uphill side and is the only one available to you. Second, at one time or another you will have to work on the horse when it can only be ground tied. Two young ladies whose parents sent them to me for horsemanship lessons have been learning about back country riding. In the photo below you can see them doing the basics. One young lady is picking the hooves of one horse while the other young lady is offside saddling another horse while both are only ground tied.

Custom Knife Failure

Well that didn't go as I'd planned. I was working at the outer edges of the envelope and I went too far. During the quenching process the edge of the blade cracked, rather uniformly down the edge. Given that the crack spacing follows the initial curvature it appears that the cracks were formed in tension in the martensitic portion of the blade. This is not particularly surprising as martensite has a different volume due to the phase change. I had clayed the blade and left the edge exposed to only transform it while keeping the spine of the knife more ductile. This resulted in a overly large curvature and the subsequent cracks. You can see the cracks in the photo.

Seki-joju Bonsai

Or root over rock style bonsai. Six months ago I started a few Mesquite trees from seed. Mesquite trees can be quite invasive so I have limited the numbers that I've planted on my land and watch out for volunteers. One of life's smaller pleasures is at the end of the day walking the property, running a critical eye over things and having one's dogs following faithfully along.  I like Mesquite trees for their nitrogen fixing properties, their drought hardiness, and they provide a good habitat for birds. But I digress...

Making a Custom Knife: Carbon Steel

A gentleman of my long acquaintance asked me to fabricate a knife for the woman in his life. Since I only do blade work for myself or close acquaintances this posed an interesting problem for me. There can be a certain intimacy in making a blade for a person as what their needs are becomes important in the overall design and can be answered only by rather personal questions. I am not in the habit of asking other women personal questions but accrued obligations are the sine qua non of my life so I accepted.  Having said that I'll walk through the process to get it clear in my own thoughts. For working with steel there is one diagram that should be engraved in the mind. The Iron-Carbon Phase Diagram.