Intro: Farrier's Rasp Knife
This is my first instructable, so I'm not sure how to begin... I made a knife from a heavy 14" x 1/4" thick farrier's rasp I bought for $5 at a flea market.
Step 1: Grinding Down the Teeth
This is after some initial grinding that took forever. Files and rasps are apparently hardened, but not tempered, so they're very hard to work with.
Step 2: Tempering to Remove Some Hardness
I tempered the file back to make it a little softer and closer to finished knife hardness. This is after two 2-hour tempers in my kitchen oven @ 400 degrees... I was looking for a light straw color, but the blues and plums tell me I may have had it in too long. I turned the oven back to 350F and heated it for another 30 minutes and got the color I was looking for.
Step 3: Laying Out the Pattern
This patten came from some aspects that I liked from 3 different survival type knives. I think the pros use a dye and scribe the pattern on... I used white spray paint and sharpie, because why not?
Step 4: Rough Cut
...as the title says.
Step 5: Cleaned Up a Bit...
Yup. Then I stripped the paint with a spray-on paint stripper and scrubbed with a toothbrush.
Step 6: Template for the Handle Scales
I had a few ideas, but ultimately went with this. It was some exposed file for the butt or pommel or whatever it's actually called and to drill a lanyard hole through. Also, I started the initial grind on the bevel.
Step 7: Grind, Grind, Grind, Drill, Heat, Drill, and Swear...
I was aiming for a flat grind, but there was just soo much grinding to do. The best I could do, (which by the way I'm very pleased with) was a 3/4 height convex grind. This will be a great chopper, hopefully.
I found it very difficult to drill through, even with a cobalt drill bit, so I took a propane torch and heated the handle up until it was as red as I could get it and let it air cool, slightly annealing the tang. The hole closest to the blade still wouldn't drill and I was afraid to heat it up more for fear that the heat would creep onto the blade and ruin the temper. So, after a little researching on the dozens of knife forums, I found that a simple carbide-tipped masonry bit would do the trick.
Step 8: Which Brings Us Back to the Finished Product.
I used curly maple for the scales and 40d nails for the pins. The nails are slightly less than 1/4" diameter and fit perfectly in 1/4" drilled holes. I buffed the blade to almost mirror with a dremel, buffing wheels and compound. The handle was first stained with 2 coats of black Rit clothing dye, then sanded back to reveal the stripes. This also left uneven gray and purple splotches which looked like crap. So in a last ditch effort I applied the only other dye I had which was dark brown leather dye that I use for my sheaths and it saved it. I think it looks like an old rifle stock now. I applied 3 thin coats of boiled linseed oil and 3 coats of paste wax. I don't quite have the finish I'm looking for, so it was suggested I wipe it down with acetone, then apply some Tru-Oil which is actual gun stock finish. For now, I'm overall pretty pleased and I hope you like it too. Thanks!