RustyLaidlaw

Count me in too! I love a healthy competition!

Would it be bad form to do an integral, or does it have to have a wooden handle? I bet I could forge and finish an integral blade in less than an hour by hand. Sharpening too!

Beautiful hammer Brian, I can tell yours just by looking. It's a brand name, the Brazeal hammer. I'd buy one. Gimme a price!

I don't know about vacuums or salt baths, but I do know that when tempering a polish is a serious no-no. Try it some time. I temper everything by hand with either a torch or a hot piece of steel, or sometimes even over the coals in my forge. I will grind the work to almost a polish but not use anything other than a belt to get it there. I aim for 600 grit typically, but on some tools like hammers and pickaxes I'll go less, an old 80 grit belt or whatever is around. The finer the grit the better to see the color change, and that was the logic that says we should polish our work before tempering. Also it's easier to clean up the temper colors afterwards - less surface area to have to scrub color out of. The emery and carborundum stone method is good for quick jobs like chisels where you want to keep the heat and use it to temper the edge without re-heating the work. As we all know when we heat our work to tempering range colors start to develop and move from the area of applied heat down towards the cooler area as heat bleeds into the work. What causes the colors is an oxide layer forming on the steel. The thickness of the oxide layer is controlled by the temperature of the steel, and causes light to bounce off the layer and causes interference that we see as colors (same as looking at anything, I guess). Anything on the work, be it fingerprints, oil, grease (as most polishing compounds are based on) or scale will interfere with the formation of the oxide and give you a bad reading or at best a blotchy coloring. The best way to finish work for tempering is to grind it down, wipe it off with a clean cloth and begin! Unless of course you have a vacuum or salt baths ;)

Thanks for the responses guys, I'm glad to help. The wife says I should write a book. I love teaching and helping folk out, so I appreciate your encouragement. Especially from someone like you Mr. Turley! Thanks again. - Rusty

Hi Dave! I use spark testing to help get a general idea, and I'm stressing general, of what grade of steel I'm working with. The spark test doesn't tell you anything specific, but can give you a good basic bit of information to go forward with. All spark testing tells you is carbon content, and can be figured as four groups: 1. Wrought Iron 2. Mild Steel 3. Medium Carbon Steel 4. High Carbon steel Any more information than that warrants a metallurgical analysis in a lab. I use an aluminum oxide wheel, 6 inch on a 1/4 hp motor spinning roughly 1750 rpm. This is important because sparks look different depending on what you're grinding with. To start, you'd do best to have a control piece of steel to compare results. I use a piece of known 1018 (low carbon), and 4140 (medium carbon). Wrought iron is almost no carbon and gives off all straight streaks with no bursts, typically. Low carbon is "mild steel" and gives off straight-looking streaks with bright tips and a couple bursting sparks. Medium carbon is more active with much longer streaks and lots of bursting sparklers forking off the main sparks. See the attached pic Sparks 1. That was done on a 1" belt grinder but you can see the streaks and forking. High Carbon is just beautiful bright fizzly sparks with no streaks. The pic Sparks 2 shows this pretty good. Aside from that, if you ever grind high speed steel you'll see very little streaks of a kinda dull orange color. It's hard stuff, and usually only in smaller bits for lathes and other machine tooling so it should be obvious if you ever run across any. Hope that helps! - Rusty

Just finished a Sgian Dubh project I had to clean off the bench today. Material: 5160 hardened and tempered Fittings: Silver alloy Grip: Kingwood Tang is through and peened over a brass washer. Total Length: 7 inch Blade Length: 3.75 inch Polished up real pretty, I always hate that feeling of despair having to let a finished piece go. Thanks goes to my fiance Hayley for taking the pictures. She's a better hand at a camera than I'll ever be.