You need to learn how to forge, not change the shape of the preform. Most smiths just use a rectangular bar of steel to forge from, but some pre-grind the basic shape before forging. Once you have the profile set, bring the blade up to forging heat and put the blade edge on the anvil horn. Gently shape the blade to a downward curve, like the reverse of a skinner (the reverse of what you've been ending up with). It should be a pretty ugly hooked blade at this point. As you start forging the bevels in the blade will rise and straighten up. If the tip gets too high, just bend it down some more the same way you did the first time. some smiths use a 12" piece of baseball bat to hit the spine when curving the blade, to avoid putting dents in the spine. Once the bevels are forged in the blade should be straight. It takes a little practice, but once you get it down, you will just hammer a down curve into the bar of steel and start forging away.
BTW, shaping the tip and establishing the ricasso point are the first steps in forging a blade, if you are not pre-grinding/sawing these in the blank.
Stacy
Here is a primer I posted a while back for another smith with similar problems:
I use hammers from 1.5# to 4# for general forging. The two you will use most are a 2.5# to 3# general blacksmiths hammer, and a 2# cross pein. Don't start too heavy. Shorten the handles to about 12-14 if they are long.Sand the butt to a smooth edge.The handle should have a good feel in the hand. If the handle is not comfortable, you will never control it. While a general purpose hammer (ball pein,engineers, etc.) will work to start with, remember that blacksmith hammers are designed to do the job precisely.A good forging hammer will cost less than $50. So a pair of hammers and a box jaw tongs will set you back about $150 total. Centaur Forge (
http://www.centaurforge.com/ ),and Tom Clark at Ozark School (
http://www.ozarkschool.com/ ) are good suppliers. I like the Tom Tongs. When you get some hammer experience, and are ready to purchase a couple of new hammers, the Hoffi hammers, designed by Uri Hoffi, are superb ( but a bit pricey).
Make sure the metal is at the right temperature. Just "getting it red" is not necessarily hot enough. It should be at a forging temperature, which for "Spring Steel", is probably between 1600F and 2100F.That is between a reddish -orange and an orangish-yellow (here is a visual chart,
http://www.beautifuliron.com/usingthe.htm ) Don't "push" the hammer hard. Let it be guided and controlled by the arm , not propelled by the shoulder. Set the work area (anvil, forge, hammers ,etc.) so you can stand comfortably on a firm, level, and uncluttered surface. You should not be bending or hunching to forge. The hammer should hit the steel so the shock does not transfer to your body. The anvil surface should be about at knuckle to wrist height when you stand next to it (this varies from smith to smith somewhat, but is a good starting guideline). Tongs are great ( necessary for some jobs) to do a lot of forging, but when learning, use an 18" to 24" bar of steel and a leather glove on the work hand ( the one holding the bar).I will save you a lesson that we all learn soon - Never get the work glove wet. It will conduct the heat directly to your hand and burn you!!! To start with, don't use a forging hand glove. You will need to learn the feel of the hammer and build up some control technique (the callouses will come on their own).I use a forging glove, somewhat like a batting glove. It covers my palm and supports the wrist a bit. Learn without one first, then decide if you want one later.
Practice for control and process.In masons terms - Don't try to build a house in one day, lay a few bricks at a time, checking with the square and level as you go. To a smith that means to do a forging session, take a look at the work done and see what went well and what didn't. A good training technique I use to teach is this:
Take four bars of 24X1X1/4" steel.
1) Take the first bar and hammer it with the forging hammer till it is 1/8" thick, starting from one end and going to the middle.It should have become wider and longer. Look at how the bar is shaped. Is it all twisted and bumpy? Or is it smooth and fairly straight. Study it for at least 15-30 minutes.Maybe run a file over the surface to see how deep some of those dings are ( do this on each of the four exercises).Now do the other half and try to correct the problems encountered on the first end. Improved? Maybe???
2) Next, take another bar and ,using the cross pein, draw it out from the center to one end, making it 1/8" thick by 1" wide. It should be longer, but not much wider. How does it look? See where you have room to improve and do the other half.
3) Take a new bar and, starting at the end and stopping at the center, bevel the bar until it is a 2" wide wedge. It should be a fairly smooth flat taper from spine to edge. Evaluate it.Now do the other end.
4) Take the last bar and taper it from the center toward the end making it longer and being 1/4" at the center and an edge at the end. (This is called a distal taper, BTW). It should end up a long 1" wide chisel. After examination, do the other end.
What you have learned here is the four processes that are involved in making a knife,without trying to make a knife.
Now you are ready to take a new bar of the same steel. Cut the end at a 45 degree angle to pre-form the point ( You will need to learn about fish lips later, but for now cut the point). Start at the point and round off the general tip shape. Now set the bar edge on the anvil edge, about 3" back from the tip. The blade edge part should be off the anvil with the handle part above the face, with the bar at a 30 degree angle to the face. Strike the spine area to make a big dent on the edge area .Straighten and smooth things up a bit. This will mark the end of the blade edge. Now, using the horn, curve the "blade" DOWN into the reverse of a skinning knife. This is to allow the blade to straighten back up as you forge the bevels and tapers in. - believe me, it will straighten.) Starting about an inch forward of the notch, draw the edge out wider to start the bevel. As you go toward the tip, taper the blade ,too. This will make it longer and wider. The end result should be a blade about 1.25" wide and 4" long. You will move the bevel back toward the notch a bit as you go, which is why you started an inch away - to allow for the ricasso getting smaller as you reforged and refined the bevel. The ricasso should end up about 1/2 to 3/4".Clean up the shape of the blade until you like the general look. You aren't looking for a finished blade yet, just a finished shape.
Cut the knife from the bar about four inches from the blade notch. Shape up the tang ( This is where you will need tongs), keeping it as smooth and flat as possible ( Tapered tangs are a thing you will learn about later, but avoid now), and clean up the blade . You can always grind/ file the details later, so as said before, "Quit while you still have a knife." If the knife looks something like a hunting knife, you have done all right. Grind and file it to smooth the surfaces and refine the profile....How much more did you have to remove?? A lot??? Next time make the hammering smoother and the surfaces flatter.
Make three more (each on a different day - yes a different day!) ,and see how each one improves. Heat treat the best one and finish the knife. Take the others, drill one small hole in the tang, and nail them over the shop door. Every time you finish a blade and are leaving the shop, look up at those and see where you have improved.
BTW, all forging steps were at forging heat, never cold or just red.
Hope this helps - Stacy
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Last edited by bladsmth : 01-05-2008 at 11:26 AM.
