Grinding and polishing are two procedures at different ends of the same process. Grinding involves quick removal of material and polishing involves very slow removal of material. In creating a bevel you start with a high grit material such as a 60 or 80 grit abrasive belt and work up to a 400 or 600 grit belt. After the belts you move to abrasive *cakes* used with polishing wheels. The level of shine that you put on your work depends on the metal and the level of abrasive you go to. It also depends on the power of the motor running your buffing wheels. A one *horse* buffer can't put the same shine on as a 2 *horse* can. To achieve a *mirror* finish you need power and clean wheels.
1. First scribe the centerline of your material with a sharp object or an ink pen.
2. Second lay out the borders of the bevel. ie - how deep toward the centerline of the blade will your bevel extend?
3. The basic positioning of the steel is to hold the blade edge parallel to the surface of the turning wheel. When doing the initial grinding I like to have my blade edge up so I can watch that the grind remains parallel to the center mark I have placed on the material, but later on when the edge is finer I tend to switch the position so that the edge lays down so that it won't *dig* into the belt and tear it. If you have a blade *rest* to steady your material on it will help you out with your early projects.
4. Make smooth *passes* along your bevel area starting at either end and moving the entire length in each pass. If you stop prior to reaching the end you will produce
*dips* in the bevel that will be hard to remove later. If you are working on a long bevel then stopping will be mandatory......in these cases *feather* your grind away from the wheel to prevent the *trench*.
5. The angle of the steel to the cutting edge of the wheel should be the same as your desired finish angle of bevel. With the primary bevel the size or nature of the knife you are making determines the bevel angle all by itself. You should stop your primary bevel short of the center line you have marked. How thick your edge should be prior to putting the edge bevel on depends on what you are making. In the case of the QIS we are making I stopped my primary bevel about 1/32 of an inch from each side - which leaves about a 1/16th thick edge. Onto this I will grind the edge bevel . You can do this by hand (and I usually do some of it at least by hand.....it's a much more delicate process).
6. The rest is fairly simple. Continue making grinding passes with your abrasive at 60 or 80 grit until you have gotten the rough area of your bevel done. Concentrate on making a straight border of bevel to body of knife with no *dips*(sight down the edge of the blade and let the glare highlight the bevel). Pay attention when you grind over the tip since heat builds up very quickly over small areas like that and you will burn your steel. What does burned steel look like? Its brown and ugly. You can usually go back and lightly grind over a burnt area and clean it up, but if you burn it enough times the metal will deteriorate and won't hold a good edge. Keep a bucket of water and a rag handy to cool your work to avoid early hardening of the steel.
7. Stop the use of the high abrasive belts when you first get the bevel outlined and move to the finer grits. If you grind the material too thin initially you won't be able to polish it in subsequent steps because there won't be material there. I usually stop about a 16th of an inch from the border of the bevel with the body and with an edge of 1/8th inch and do the rest as polishing steps. It brings you to your margins at just the right finish.
8. Move from the 60 or 80 grit belt to the 120. Make several passes over the bevel until it has a uniform satin finish. Then switch to the 220 grit and so on until you reach a 400 grit. Now you are into the polishing steps.
9. Polishing is the act of replacing deep scratches with lighter ones. If you were to look at a mirror smooth steel finish under a microscope you'd see a series of parallel scratches. The trick is to get the scratches to a size that appeals to your eye. I don't care for extra shiny Klingon weapons. I think a warrior that uses his blade and cares for it properly will have more of a satin finish. If you are using carbon steel or titanium you won't be able to get a mirror surface anyway. I usually stop at the 400 grit belt and don't even go into the buffing wheels with Klingon weapons.
10. Last tip. Try this out on a *test* blank so that you can get the feel for steel removal and the positioning necessary to achieve your desired bevels.
We'll discuss the edge bevels next time.
*mupwI'* Vol. 2/No. 1
*mupwI'* Vol.2/No.4 Part Two