I want to give an overview of how I make Damascus steel, along with some opinions and ideas about it. This is what works in my shop for me.
Making Damascus is almost a faith-based pursuit for me. If you talk with several people that are serious about Damascus you will see why I say it is somewhat like religion—we are all trying to get to the same place, but often value different formalities in the practice of getting there.
My advice for anyone wanting to start making Damascus is to learn everything you can and use what works for you. Nobody is born knowing this stuff. At the end of this article I will credit some of the people I have learned from and mention resources I value.
Most steels and even wrought iron, can be welded and manipulated to create patterns. If you put wrought iron, mild steel or nickel in the original billet, you run the risk of having layers that won’t harden or the lower carbon layers robbing from the higher carbon layers, possibly resulting in a blade that won’t respond properly to heat treatment.
In some cases, like with a tomahawk, in which a tool steel bit will be used, softer layers can be acceptable because only the working edge needs to be hardened.
I use nickel in my bars only when my informed customers ask for it. Nickel really does make a piece pretty and, in my business, whoever is paying can choose what material they want.
Some steels aren’t compatible in a billet. You run the risk of having a piece tear apart during heat-treat due to radically different alloying elements in the steel, causing differential rates of expansion and contraction under extremely quick temperature changes.
My personal recommendation is 1084 and 15N20. This combination provides everything I want for a piece that I can provide to others with confidence. The 1084 will be very dark, and will contrast nicely with the 15N20 (which will be bright). These steels are similar in composition and perform well in heat-treatment, and make outstanding blades. I also believe they stand up better to mismanagement (time and temperature extremes) than some other mixes.
Wire rope and a chainsaw chain also can provide some cool patterns. While wire rope welds up easily, both it and the chainsaw chain are hard to complete without small flaws.
Billy Phelps, a talented blacksmith, said: “To forge weld requires 2,400 degrees and 800 pounds per square inch.” I think it would take lab conditions to prove this, but it seems reasonable to me. I do know higher carbon-tool steels will weld at slightly lower temperatures than mild steel, and wrought iron needs to be screaming-hot to weld or even to forge successfully. A coal forge will certainly reach the required temperature, and I use it often for welding certain general blacksmithing projects. For pattern-welded blade steel, a good blown propane-fired forge is hard to beat.
Over many years I have found the blown forge to give me total control over the most critical concerns: atmosphere, temperature and time.
One question I get a lot is how I know when the steel is ready. The first thing I would say is that it is essential that you’re able to see the work. Seeing the work requires some type of eye protection, which is a whole subject itself. I use a Shade 3 welding lens. Use some kind of eye protection when welding, even in coal. I believe if you can see the work, it can be better managed.
Experience is the best teacher as you learn the particularities of your forge and the lighting conditions in your shop to determine the right color of the hot metal. Keep in mind that whatever eye protection you choose may affect how your eyes see the color of the metal as well.
For me, when the flux is violently active and the billet appears the same color as the inside of the forge, I wait a few more minutes so the heat of inside of the billet can catch up, and then I apply pressure. It’s a feel that comes after making a few pieces that fail. A piece will not weld up well if it’s too cool, but a long soak time at welding temperatures is not good for the steel, either. Although plastic deformation and thermal cycling can repair some of the grain damage done by overheating, a piece with bad welds isn’t useable. Managing the compromise is part of “the feel.”
Many people use 20 Mule Team Borax right out of the box. I can’t recommend that because, with that method, most of it quickly hits the floor or the bottom of the forge. Anhydrous borax is a much better alternative, and all things considered, may be more economical. With anhydrous borax, more flux stays on the work and seems to penetrate better, so less is wasted.
There are other things that can be beneficial in flux. Here is a recipe for Super Flux that I share with permission from Chuck Robinson of Picayune, MS “15 Parts Borax, 6 Parts Boric Acid, 3 Parts Iron Oxide and 2 Parts Fluorspar”. I like this mixture a lot. I have welded stainless to carbon, in atmosphere, with this flux, which is something some say can’t be done. But be warned — fluorspar isn’t healthy and only use it with good ventilation or proper breathing protection. I like to use a lot of flux. Consider that the job of flux is to remove oxides and trash. I like to see the flux dripping off the billet taking the unwanted stuff with it. For me the proper amount is what stays on the piece at welding temperature.
The time to introduce the flux is just before color shows in the work. A faded red will melt the flux, and that is when it starts to do its work. Making the weld basically requires that enough pressure be applied to the stack of individual pieces to force out the flux and molten scale so that the steel surfaces are in contact inside the welding temperature range. There are many ways to accomplish this.
While a hand hammer will certainly work, a power hammer can hit it many more times with the amount of force I determine while at welding temperature. Extreme, hard blows aren’t what are called for when making the weld, but lots of moderate well-placed blows are. The faster you can overlap the last blow with the next one, the better. Whether power or hand hammer, the first series of overlapping blows should cover the center of the billet, and the next series should go down the side, overlapping both the last blow with the next one, but also overlapping the previous series of center blows.
Power-hammer dies should not be flat for this work; they need a small amount of crown in the center to help push the trash out, not help trap it. I’ve found through experience that a forging press is an even better (cleaner, faster and more consistent) way to set the weld. I think the press is better due to forging dynamics that are beyond the scope of this paper.
After the weld is set, there is the problem of drawing out in preparation for a fold or a stack. For me, that is accomplished with a combination of the press and the power hammer. The press is the brute-force tool and the power hammer is used for finesse. Building up layers can be accomplished either by folding to double each time or drawing out and cutting the bar into multiple pieces and re-welding.
I use both methods, but typically draw out enough to cut five or six pieces, then re-stack the billet for another welding cycle. Sometimes I even do that again. Then sometimes will bifold or trifold to reach a predetermined layer count. Some patterns look better in higher layers and some in lower levels. and Damascus billet customers know the range of layers they want the piece to have. Again, the guy that is buying has the correct idea.
I have a McDonald rolling mill that is used for final forging steps. The mill is the most efficient tool for working to a desired thickness, and it leaves a cleaner, more consistent surface than my other forging tools. Many people forge Damascus by hand, but I would never recommend it due to potential damage to your body—and your frustration level.
Just managing a moderately sized billet against the leverage of a long handle (necessary to isolate from the heat) can really hurt your elbows in a short time. I solved this problem by using a device called a tool balancer to carry the weight of the workpiece. The tool balancer was recommended by a friend (Charlie Murray), and may be the single best thing I have found to helping to produce Damascus. When you are doing this for many hours a day, several days in a row, anything that makes it physically easier allows you to work longer, faster and safer.
After the preferred layer count is reached, something needs to be done to make a pattern happen, otherwise you will just have a straight pattern, provided everything has gone as it should have up to this point.
Patterns are usually created by manipulating the steel mechanically or by stock removal. Twisting is an example of mechanical manipulation. Drilling holes or milling grooves are examples of how stock removal followed by forging can expose layers to create a pattern. Different dies can be used to make impressions in the surface, and then when the raised areas are milled away, a pattern appears in the exposed layers.
Expect to lose up to two-thirds of the material you started with in grinding out these stock-removal-developed patterns. Remember, the last forging cycle before pattern development needs to leave a piece three times as thick as what you want to end with. You will be drilling or otherwise cutting one-third of the thickness from each side and forging it to the middle, or deforming one-third the thickness from both sides and grinding to the center third.
Stay tuned for Part Two, which will cover Etching and Problems to look out for.
By Matt Walker