Want to know more about leather carving knives (swivel knives)?
They're like anything else--I've bought fancy nice new ones and my favourite still ends up being the crappy $10 knife I've used forever.
Doesn't stop me from wanting to find that elusive perfect knife though.
Every couple of carvings I like to do a quick sharpen. Sharpening swivel knives is a bit different than your regular knife sharpening (for one, I don't have fine enough stones--I really need a good extra fine diamond hone one of these days), but you start out with usual supplies: stone, honing solution stuff. I've got a nice fancy-ass sharpening guide as well--this is for keeping the ideal angle preserved on the knife edges of 30 degrees. It makes a delightful metal-on-metal screech as it rolls.
Swivel knife blades can be pretty thick and end up with two flat sides of a v-shape tapering to the edge. You sharpen one side, sharpen the other, then pull back a couple of times on the original side again to remove any burr that has built up. The trick is making sure the angle is still properly set--hence this holding guide thing. The second trick is knowing when you have actually sharpened down enough to reach the sharp edge--it's good to colour in the edge with Sharpie and then check on it to make sure all of it comes off properly and the full flat surface has been sharpened down.
Of course, in the leatherworking world there is also proprietary bull****. That is, the guide only works for one sized blade for one manufacturer. So for my super 3/8 inch knife, I have to do this the old fashioned way, feeling the angle of the flat face and hoping I don't screw the blade up.
Here is a comparison of my three blades and their sizes: an angled detail knife, my good old crappy knife, and my big Barry King knife (which I bought reading they were supposed to be amazing and I ended up not really liking at all--I do not have the burly manhands required for this powerful instrument).
So before each carving session, I strop the knives, and in between every couple of cuts I re-strop on the finer compound. People who are into fancy straight razors and shaving stuff will recognize this kind of setup. First the coarser side:
Then the fine green stuff:
So this is the knife prep before carving something. I actually do use all three of the knives for different purposes. For example, here's what I worked on the other day:
You can get a thicker or thinner carved line depending on the angle of attack and pressure of the blade. However, for the small ticks and flourishes, it's simplest to use the big blade to do them first. I also use the thick blade for the straight lines, both because on this script they're quite thick and emphasized and because bigger blade=straighter line.
Here's the same piece just after I have filled in the rest of the letters using my normal knife:
You can see all the test work I do in the background--I had to figure out what the best combination of blades and tools were for these letters, whether bold or regular worked better, and so on. I always do at least one practice for every carving I do, but this one took a lot more figuring out since something simple is the simplest to make look bad!
