Making a Woodworking Marking Knife by Epicfail48 on January 8, 2017
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technology workshop craft home food play outside costumes Making a Woodworking Marking knife by epicfail48 on January 8, 2017 Table of Contents Making a Woodworking Marking knife . 1 Intro: Making a Woodworking Marking knife . 2 Step 1: Step 1 - Gathering Materials . 2 Step 2: Step 2 - Layout, Rough Cutting, and Shaping . 6 Step 3: Step 3 - Pop some holes in it . 7 Step 4: Step 4 - Heat Treatment . 7 Step 5: Step 5 - Polish and Sharpen . 8 Step 6: Step 6 - Making the handle . 9 Step 7: Step 7 - Use It! . 12 Related Instructables . 12 Advertisements . 13 Comments . 13 http://www.instructables.com/id/Making-a-Woodworking-Marking-Knife/ Author:epicfail48 author's website Amateur Bladesmith, hobbiest woodworker, and a bloody good cook Intro: Making a Woodworking Marking knife There are 2 types of people in this world; those who have used a pencil to mark a cut line on a piece of wood and dirty liars. Now, a pencil is an excellent tool, and one of the most used in a woodshop, its hard to beat the convenience for marking a cut line. For some tasks though, like laying out dovetails or other precision joinery, a pencil mark doesn't, ermm, cut it. I'm so sorry, i tried to find a better pun... Anyway, the line is too thick, and its hard to get a pencil butted right up against a straight edge to put the line right where it needs to be. What to do? The traditional solution to this conundrum is a special tool called a marking knife. Made with a sharp point and a chisel-ground blade, this knife is meant to sit flush with a straightedge and reach into tight corners, and leave an extremely fine line where you want the cut to go by actually cutting the top few fibers of the wood. The resulting cut is finer than even the finest pencil line, is located right where you want it, provides an excellent groove to start a chisel or saw in, cant be erased or smudged, and the fine point of the knife can reach into right corners better than any pencil. Really, a marking knife is a brilliant tool for just about any carpenter to have. Sound interesting? WHo am i kidding, of course it does! Lets make one, shall we? Step 1: Step 1 - Gathering Materials This is an extremely simple project, from start to finish you need a hacksaw, a file and a drill. No complicated tools or materials needed, although to be fair the complicated tools do make the process easier. Im going to list the essentials first, then the non-essential but handy items Materials 1. Steel - No, the cold-rolled from your local home improvement store wont work. What you want here is a good, high carbon steel. If you've never made a knife before, i recommend O1 steel, its easy to work with and heat treat. Youll need a piece 1/8" thick, 3/4" wide and 6" long. A place like Grainger will have this if you need a source. 2. Handle material - You could use nearly any type of wood, micarta, G10, metal, whatever you want really. Whatever you use, you need 2 matching pieces of it, 1/4" thick, 3/4" wide and at least 4" long, though i recommend starting with an oversize piece. Ill be using a some stabilized Walnut 3. Pin material - you'll need a piece of round stock 1/8" in diameter. This can be brass, stainless steel, copper, whatever really. You'll need about 6 inches worth. I'll be using brass here Tools 1. Saw - You need a way to cut the metal. A good, high-tension hacksaw with a bi-metal blade will run you about $20 and is an excellent investment. Ill be using a portable bandsaw on my end though 2. File - You'll need this for shaping the blade and putting in the bevel, as well as shaping the handle.. A good 10" bastard cut mill file is again an excellent investment, for the whopping price of $10 3. Blow torch - You'll need this for heat treating the blade, provided you choose to heat treat it yourself. Also usable are a fire with an air blower for the low tech, a gas forge if you have one, or what ill be using, an electric kiln. You can also send out your blade for heat treatment 4. Sandpaper - For smoothing and polishing the blade, as well as the handle 5. Drill with 1/8 bit - For putting the holes for the pin in the blade and scale materials 6. Sharpie - Layout work Thats all you need, though one of those things isn't strictly needed. Now, a few tools that aren't necessary but do make the process easier: 1. 2x72 Belt grinder - Used for shaping the blade and grinding the bevels, as well as shaping the handle. Not needed, but awesome to have. A hand-held belt sander could also be used, its just slower 2. Portable bandsaw - Ill be using this to rough cut the blade, it's faster and involves less work than a hacksaw 3. Drill press - Makes drilling holes in metal so, so much easier. Seriously, get one, even if you cant find a sweet 1950's floor press to restore. 4. Layout fluid with a carbide scribe - I use Dyechem, makes better lines than a sharpie and won't wash off 5. Digital calipers - Again, helps with layout work. I recommend getting a set, they're dirt cheap and are useful for everything. I use this Wixey set, as they display fractions as well as decimal inches. http://www.instructables.com/id/Making-a-Woodworking-Marking-Knife/ Alrighty, got the essential materials and tools? No? Dude, what are you waiting for, we've got to get to the next step! Image Notes 1. High-tension hacksaw frame 2. Yours will work better if theres a blade here 3. 10 inch mill file Image Notes 1. Piece of 1/8" thick steel. I cant follow my own directions, so this piece is 1 1/2" wide. Guess ill make 2 blades Image Notes 1. 1/4" thick handle scale material. This isnt the piece ill be using, i just forgot to take a picture... http://www.instructables.com/id/Making-a-Woodworking-Marking-Knife/ Image Notes 1. Portable metal-cutting bandsaw 2. My super-fancy saw stand Image Notes 1. Meet Frank, my 2x72 belt grinder 2. 3M Trizact Gator Grit grinding belt. These are amazing http://www.instructables.com/id/Making-a-Woodworking-Marking-Knife/ Image Notes 1. Really bloody old drill press. Looks new, dont she? Image Notes 1. Meet Sydney, my heat treatment kiln. Gets up to 2000f and will burn you if you get too close 2. Digital controller, will hold temperatures within 5 degrees 3. #50 quench oil, i recommend using canola oil unless youve got $140 to spare http://www.instructables.com/id/Making-a-Woodworking-Marking-Knife/ Step 2: Step 2 - Layout, Rough Cutting, and Shaping Alrighty, time to start making stuff! First, take your bad of steel and cut off a piece 6" long. Go ahead, I'll wait. Got it? Okay, time to lay out the point. I've found about a 35 degree point to give a sufficiently pointy edge. No protractor? Geez, you just aren't prepared at all, are you? 'S okay, neither am I. Make a mark 1 3/4 back from one of the corners on your piece of steel, then draw a straight line from that mark to the opposite corner. That'll give you roughly the right angle, its close enough for this application. No, go ahead and use your hacksaw to cut off most of the waste, then use your file to bring it right up to the line. Take your time, you can take more off but you cant put it back. Consult the pictures to get an idea of the shape, if you don't already have one. Now you've got the rough profile of the blade down, so lets put in some bevels. Since the angled edge, the one you just cut, is going to be the cutting edge, we'll be putting the bevel there. The angle were shooting for here is about 25 degrees. To approximate that, draw a line parallel to that angled edge just a hair over 1/4 of an inch away. Once you've got that line draw, go ahead and use your file to remove the metal between that line and the edge, but don't go all the way down. Leave about the thickness of a dime on the edge. make sure to keep the bevel nice and flat, with a consistent angle all the way across. It sounds a lot harder than it is, just take it slow and work to the lines. A word to the wise, the side of the blade you put the bevel on does matter. The knife shown is a right-hand bevel, meaning that when held the flat side of the blade will be on the left, and the bevel will be on the right. South paws should put the bevel on the other side Now, i used my belt grinder for this, so it took me about a minute and a half, taking my time. With a file, this shouldn't take more than 15 minutes. If you have one, a belt sander with a 60 grit belt will put in a decent bevel in less time, but I'm keeping my instructions simple.