Rick Dunkerley

Today there seems to be a damascus maker on every corner, and the opportunity to learn to forge damascus is available to almost anyone. In 2005, the American Bladesmith Society slated seven damascus classes at the Bill Moran School of Bladesmithing. The Sierra Forge and Fire School held several classes, one taught by yours truly. There are numerous “hammer-ins” around the country and most have forging damascus on the agenda.

Be warned that forging damascus is addictive. I once heard Daryl Meier, who I consider the greatest modern maker of damascus steel, say, “Making damascus steel is a disease for which there is no cure.”

In my own shop, I try to keep things simple. By eliminating as many variables as possible, I am successful at making good forge welds. I have developed a routine that I go through with each forge weld, and by not altering what I know works, I’m confident that my welds are going to turn out good.

First in the process of forging damascus is the selection of materials to forge. This is an area that I feel strongly about and I recommend 1084 and 15N20 as the steels to combine when forging damascus. Devin Thomas suggested these materials to me almost 10 years ago and I feel they have been instrumental in my success. First, 1084 is simple steel with .84 percent carbon and .9 percent manganese. The manganese defines it as deep-hardening steel and turns it darker after etching, allowing for more contrast with the lighter 15N20.

As for 15N20, it is basically 1075 with 2-to-3 percent nickel, which results in extra toughness and gives it the quality of resisting etching, resulting in a silver layer almost as bright as pure nickel. This combination of materials welds easily and can be manipulated extensively. Blades made of 1084 and 15N20, if heat-treated properly, cut extremely well and are tougher than nails.

As with my philosophy on knifemaking, I like my forge to be simple—one burner with a small blower to provide air. The forge must be capable of reaching 2,300 degrees Fahrenheit, which is no problem with a properly regulated propane forge.

I use ceramic fiber insulation in my welding forge, which is coated with refractory cement to help resist flux and also to protect the ceramic fiber from damage. Cast-able refractories work well for insulation also. They take longer to heat up, but hold the heat well and shorten the re-heating time of the billet during the forging process. There are many good forge designs out there and my advice is to find one you like and buy or copy it.

For about 12 years I have been using a hydraulic press to make damascus. The hydraulic press has several advantages over a power hammer. For the beginner, the press is much easier to control, and dies can be made for the press that encapsulate the entire billet, making the forge weld much easier. For those with less than understanding neighbors, the press is quieter than a power hammer.

The ability to change dies quickly can be handy at times. The press I currently use was made by Jeff Carlisle of Great Falls, Mont. I have employed a good number of presses over the years and have not found one that I like better. Dr. Jim Batson sells plans for a press similar to the one that Carlisle markets. If you decide to purchase or build a press, I would recommend that it be at least 20 tons and have a good quick-change die set up.

Power hammers embody the traditional blade smith tool and have been used to make tons of damascus. I have used hammers ranging in weight from 25 pounds to 500 pounds at hammer-ins and friends’ shops over the years. Hammers are more fun to run than a press once you get the hang of them. They also distort the patterns or figures in steel billets less often if the operators have good control of them. Bars can be drawn down more quickly with hammers than with presses, and power hammers tend to knock forge scale off rather than forge it into the billets as presses will do.

Whether you choose a press or a power hammer, remember these machines can be dangerous. Combine all the mechanical power with steel that is 2,300 degrees and serious injuries can occur. Always think safety first when operating a press or power hammer.

In preparing a billet for the first forge weld, I stack alternating layers of 1084 and 15N20 to get the desired number of layers in the billet. This may be as little as three or as many as 25 layers for the initial weld. The layer count is tailored to get the desired effect in the finished blade.

I always keep the thicker of the two materials on the top and bottom of the billet, which helps to hold the heat and aids in decreasing warp as the billet comes up to welding temperature. The 1084 comes with light mill scale, which I do not clean off, and 15N20, as I buy it, has no scale and is used as-is.

After the initial forge weld, the billet is reheated and drawn out into a rectangular bar. The size of this bar is dependent on how many layers are desired in the finished billet and the finished size. The bar is then ground clean of forge scale on the surfaces that will be welded during the second sequence. The bar can be hot-cut and folded onto itself during the drawing out process to double the layer count. I have had better success with the grinding and cutting process, but use whichever works for you.

The second weld will progress just like the first, and the number of layers will dictate whether a third, or more, welding sequences are necessary.

These forge welds can be accomplished by using two different methods, namely welding with flux, referred to as a wet weld, and welding without flux, which is a dry weld.

The steps to be followed for a wet weld are:

1 Start with a 19-layer billet consisting of 10 layers of 1/4-inch-by-1-1/2 inch-by-6-inch 1080, and nine layers of 1/2-inch-by-1-1/2-inch-by-6-inch 15N20, which are stacked in alternating layers with the thickest material on the top and bottom of the stack;

2 Clamp and weld one end and then weld a handle on that end. Weld one corner at the end opposite the handle;

3  Place the billet into a forge that is preheated to 2,300 degrees and soak until the billet is dull red. At this time apply anhydrous borax as flux;

4 Allow the billet to reach welding temperature, which is indicated when the flux is bubbling rapidly. Rotate the billet to make sure it is heating evenly;

5 Weld the billet using a press or hammer. If using a press, use dies that are longer and wider than the billet to weld in one squeeze. If using a hammer, weld from the handle end outward to allow the flux to escape;

6 Use a wire brush to remove the flux and scale. Reheat the billet and forge into a rectangular bar, reheating as many times as necessary to reach the desired length and width;

7 Allow the billet to cool and grind any scale off of the billet. Cut the billet into as many pieces as required to reach the desired number of layers; and

8 Repeat the welding process and draw the billet out to the desired dimensions. The process may have to be repeated again to get the required number of layers.

By creating an inert, oxygen-free atmosphere, forge welding can be accomplished without flux, known as a dry weld. This will usually result in a cleaner and stronger weld. This oxygen-free atmosphere can be created several different ways:

1 Make a sheet metal box that the billet is placed into, and then weld the box closed. Spray a small amount of WD-40 inside the box, or place a small piece of combustible material inside, to burn off any oxygen inside the box;

2 Weld all exposed seams of the billet to seal oxygen out; and

3 Use square tubing of an appropriate size to contain the billet.

Forge weld as described in the wet welding sequence, omitting the flux. After the billet is drawn to the proper dimensions, the box or tubing must be ground off of the steel. If it becomes necessary to cut and restack the billet, there are three options. It can be put into a box, the seams can be welded to do another dry weld, or flux can be used to do a wet weld.

The desired visual effect and the pattern will be factors in the number of layers in the finished bar. I prefer a predominantly black-looking damascus, so I like the 1084 layers to be approximately twice as thick as the 15N20 layers. Because of its nickel content, the 15N20 layers do not compress as much as the 1084.

As the layer count increases, the initial difference between .25-inch 1084 layers and .075 15N20 layers becomes much smaller. This initial size difference seems to balance out to the effect that I like at 200-300 layers. Some experimentation with different thicknesses will teach the beginner how best to achieve the desired effect.

The damascus pattern applied to the blade will also be a factor to be considered in the layer count. In my view, random patterns seem to look best with at  least 200 layers. Twist patterns do no need as many layers, as twisting the bar tightens them. Fifty to a-hundred-and-fifty layers work well to achieve a twist pattern. For a ladder or raindrop pattern, 200 to 300 layers are ideal and, with a good etch, will give a holographic effect to the blade.

These are by no means the only methods for creating damascus patterns. It is my hope that you will take this information and come up with your own ideas. These methods are meant to be building blocks, and by combining them or modifying them, you may come up with something truly unique.

Once a blade or bar of Damascus has been forged, it must be prepared for heat-treating. The first step is three thermal cycles to relieve stresses imparted while forging the damascus. The thermal cycles consist of heating the bar to non-magnetic and allowing it to cool for several minutes.

This is repeated two more times, and after the third heating, the bar can be allowed to cool to room temperature, which is a normalizing step. This process greatly reduces the possibility of the blade warping during the hardening process.

The blade or bar of damascus is then ready to anneal. It is again heated to non-magnetic and placed in vermiculite to slow the cooling process. After approximately six hours, the steel is annealed and can then be drilled and ground easily.

After drilling any holes needed and grinding to a 120-grit finish, the blade is ready to harden. If the forging was uneven and required grinding one side of the blade more than the other, I recommend several more thermal cycles before hardening.

The hardening process for bars forged of a combination of 1084 and 15N20 goes as follows: heat the blade to 1,500 degrees in high temperature salt; hold for two to three minutes; quench in preheated (120-degree) oil; and the allow the blade to cool until it can be handled comfortably bare handed.

This should result in a Rockwell hardness of 62-64 Rc. Two tempering cycles of one hour each at 400-425 degrees should produce a blade with a Rockwell hardness of approximately 58 Rc. If high temperature salts are unavailable, the blade can be heated to nonmagnetic and quenched with similar results.

This same heat-treating recipe will work for other combinations of simple steels. The tempering cycles should be at a lower temperature (350 degrees) and raised 25 degrees incrementally until the desired hardness is obtained.

The hardened and tempered blade must then be finish-ground and hand sanded so that it can be etched to reveal the damascus pattern.

I grind my blades to a 320-grit finish and begin hand sanding with 400-grit wet and dry paper. The sanding is done perpendicular to the 320-grit belt marks until they are gone. Then 600-grit wet and dry paper is used to remove the 400-grit scratches.

How to Make Basic Patterns

The layer counts are only a starting point and you may find that you prefer more or less. In specialized damascus patterns, such as radials or jellyrolls, far fewer layers are needed. It is also possible to forge weld sections of high- and low-layer bars into one billet and get a high contrast through patterning.

Patterning of the flat laminated billet can be accomplished in many ways. Random pattern needs little explanation. The layers remain relatively flat and some distortion usually occurs during the forging. The distortion causes the flat layers to bend and results in a flowing, organic look to the material, especially when the edge bevels of the blade are finish-ground.

Twist patterns are similarly self-explanatory. A bar of the desired number of layers is forged into a square and the corners are forged down slightly. The bar is heated until it is close to welding temperature, and then twisted. The twisting can be gradual or tight for varied effects. The center of each twist gives a star effect. Twisted blades should be left a little thicker than other patterns as grinding deeper makes the star effect greater and the overall look is more pleasing.

Ladder patterns are accomplished by pressing or grinding grooves across a damascus bar. If the pattern is pressed into the blade, it should be approximately double the thickness required in the finished bar. The grooves are pressed in with dies made of round rods, and stop blocks can be used to insure the proper thickness of the finished bar.

After the grooves are pressed into the bar, it is ground flat, removing all the high spots. The bar is forged to the desired blade shape and the ladder pattern becomes visible. If the ladder designs are ground or milled into the bar, they should be approximately one-third the thickness of the bar. After the grooves are ground, the blade is forged to shape with all the grooves forged out of the bar, resulting in a distinct ladder pattern. Whether pressed or ground, the ladders should be staggered from side to side.

Creating the raindrop or pool-and-eye pattern is essentially the same process as forge welding a ladder pattern, except that dimples are pressed or drilled into the damascus bar instead of grooves. The resulting pattern will look like bull’s-eyes or raindrops on a pond.

These are the most basic damascus patterns and the same patterning techniques, and several others, are employed for more advanced patterns. Before moving on to more advanced patterns and techniques, the damascus steel maker should become adept at the forge welding process.

How to Make the “W’s” Pattern

More advanced patterns include the “W’s” design, and mosaic damascus. With the “W’s” pattern, the initial billet is stacked just like a flat-layered billet, and welded. Then, during the drawing process, the billet is rotated 90 degrees and forged into a rectangular bar with vertical layers. This bar is then ground free of scale, cut into pieces and restacked.

When the second weld sequence is complete, the layers remain vertical. This bar is then cut again and restacked for the third weld sequence. If the ends of these pieces are etched, they will reveal vertical layers that are distorted and starting to form the “W’s.” The third weld sequence will distort the layers even more and make the “W’s” much more dramatic. Any layer count works well on this pattern, and any of the patterning techniques, including twists, ladders, raindrops and even accordions, help to further expose the pattern.

The next level of advanced pattern welding is the making of mosaic damascus. The patterns in mosaic damascus are visible on the ends of the bars, yet what truly comprises mosaic damascus has never been clearly defined. At the BLADE Show in 1999, I questioned some of the best damascus makers on hand as to their opinion on this topic and each one had a different definition for mosaic damascus. Since there seems to be no clear definition we will refer to all end-grain patterns as mosaics.

How to Make Basket Weaves, Spider Webs and Radial W’s

The basket weave or parquet is a relatively simple mosaic-damascus pattern and makes for a good first mosaic project. To begin, forge weld a low, 5-to-9-layered billet and draw it out into a 1-inch square bar. Cut this bar into four pieces and stack them into a 2-inch-by-2-inch square, with the horizontal layers in two opposing corners, and the vertical layers in the other corners.
Forge weld the stack and draw the bar out, keeping the bar square by forging evenly on all sides. Several series of cutting and re-welding as described above will give a nice basket-weave pattern, a design that works well for background filler in complicated mosaic projects.

The spider web or grid is another simple mosaic pattern. It is started with squares of solid steel, such as 1050 or 1095. Cut four squares of the steel and stack them into a square billet. Add shims of contrasting steel, such as 15N20 or pure nickel, and then forge weld and draw the billet down into a 1-inch-square bar. Cut the bar into four pieces, stack, and re-weld until the desired size grid is achieved. The grid may be intentionally distorted by forging on a bias to create a spider web-like effect to the pattern.

Another mosaic-damascus pattern is the radial. The radial design is started with a low-layered billet of flat laminates. The bar is cut with a die, which compresses the center layers. The halves are then cut into four pieces, stacked into a square and then forge welded back together. This gives the effect of the layers radiating out from the center of the square.

The radial technique applied to a “W’s” pattern bar accomplishes a spectacular design. As with all of the patterning techniques, you can try them with any billet that you like. You never know when you will come up with a great new pattern.

Four-Way and Nine-Way Forging

For the best effect in the finished blade, it is often necessary to incorporate more than one radial or one jellyroll in the pattern. A bar can be cut into four pieces, stacked into a square billet of two rows of two pieces, and forge welded. This is referred to as a “four-way.” The bar can also be cut into nine pieces and stacked into three rows of three pieces, or a “nine-way.”

These four- or nine-way billets may be repeated several times to accomplish the desired effect. The size of the blade to be made will dictate the number of the original elements in the finished bar. For large fixed-blade knives, I like at least 16 of the original elements, and two four-ways will accomplish that number.

For small fixed blades or folders, I use 36 or 64 of the original elements in the bar. To achieve 36 elements requires a nine-way and a four-way, while a billet of 64 elements is accomplished with three four-ways. These numbers are only recommendations, as personal preference will dictate how each blade smith uses the material.

Single patterns or several different patterns can be combined in four-way or nine-way combinations, resulting in extremely interesting patterns with high contrast. There is no end to the possibilities for creating patterns with these combinations.

After combining and forge welding the desired number of elements, there are several ways to expose the pattern that is on the end of the bar. Twisting the bar and then forging to shape will expose the pattern along the edges of the blade. As with any twisted bar, the edge should be left fairly thick so that more grinding is required because the pattern is better near the center.

To expose the pattern, the bar can also be forged into a rectangular shape and ladder patterned either by pressing the ladders into the bar or grinding them in. And although I have never used it, the raindrop patterning technique should also bring the pattern to the surface of a rectangular bar just as well as the ladder pattern method.

The Accordian Method

The accordion method is my favorite way of exposing an end grain or mosaic pattern. I like the appearance of movement and flow that is created by the accordion technique. There are several different methods that can be used to open a bar like an accordion, and I use one suggested to me by Don Fogg.

The damascus bar is forged to final dimensions and annealed. The bar is then cut on a band saw, removing triangles of material from alternating sides of the bar. After all of the cutting is done, the sharp corners are rounded off on a grinder. The bar is then ready to flatten. While flattening the accordion, the bar should be worked at a welding heat. If the bar tears at the bottom of the cuts, apply flux and gently weld them closed. I can usually flatten the whole bar in one heat. The bar is then forged to final dimension.

The cut-out-triangles accordion method has worked so well for me that I do not use other accordion methods. This method is more labor-intensive, but at this stage, the damascus bar is valuable to me and I do not mind a little extra work to help maximize the material that I obtain from the bar.

The Loaf Method

Another popular method of exposing end grain patterns is the loaf method. The loaf method is accomplished by forge welding several blocks together side by side and then slicing blades off of the loaf. It is helpful to surround the blocks with sacrificial material like damascus or plain carbon steel. The seams can be welded shut and the billet dry welded. Having the blocks fit together nicely will simplify the weld. The loaf method works well for patterns or figures where no distortion is desired.

Cutting tiles off the bar, dovetailing them, then forge welding them together is one more way to expose patterning and produce blade material. This is a difficult forge weld and I do not recommend it for the beginner. The tiles are usually tack welded to a sacrificial plate, which is ground off after the forge weld. This method also does not distort the original pattern.

The Plug Method

The final method of exposing end grain patterns to be addressed is the plug weld. The original bar can be turned or forged into a round bar and plugs are then cut off. A hole is drilled into a blade and the plug is fit into the hole. A good, tight fit is desirable, and the plug should be slightly thicker than the blade.

The blade and plug combination are heated to a welding heat and welded in one press or hammer sequence. Several plugs can be welded into one blade if desired. This is another method that does not produce distortion.

There are times when distortion can be used to enhance a pattern or even create a new pattern. By forging a square bar on a 90-degree bias, the pattern in the bar will be distorted. The distortion continues as the bar is forged on the bias until it is square again. This can then be used as is, or incorporated into a four-way or a nine-way.

How to Make the “Persian Ribbon”

A pattern that is not so spectacular can be brought to life by using distortion to your advantage. The squares in a four-way will be triangles after a 90-degree bias forging, and can then be oriented on the next four-way to create diamonds in the pattern.

This is the technique used to create the pattern I call “Persian Ribbon.” Four blocks are stacked in a square with borders of contrasting material between the blocks. These are then forge welded and turned on a bias, with the borders now creating an “X” across the bar. The bar is then opened up using the accordion method and the Persian Ribbon pattern is created by the “X.”

Creating Custom Images

Beyond damascus patterning is the topic of creating figures within the damascus steel. Placing pictures in damascus has now become commonplace, as I have seen bird-hunting scenes and the outlines of mammoths, shamrocks, dragons and countless other objects in blades. The use of powdered steels has made creating these figures and pictures much simpler.

Prior to the use of powdered steel, an EDM (Electrical Discharge Machining) machine could be used to cut a figure from two blocks of contrasting steel, and the male parts were interchanged. Forge welding resulted in two bars with the same figure, one dark and one light. This method was very expensive, and although intricate details could be cut, distortion was still a problem with uneven forging.

When using powdered steel, one block can be cut on the EDM machine and the figure is then removed and the hole filled with contrasting powdered steel. The male part can be placed in a square tube with one end capped, filled with a contrasting powdered steel and forge welded. This yields two bars with the same figure for half the cost of the EDM work.

A second method for making figures or pictures in steel is to cut plate material and stack the plates. The plates can be cut by laser or water jet less expensively than with an EDM. The plates are stacked in a square tube, and the cut-out figure is filled with contrasting powdered steel, and forge welded. I suggest that the first weld be on the ends of the stack to weld the plates to each other and prevent the powder from sifting between them.

The billet is then forged out into a square bar with the figure on the end. This method provides great detail for a fraction of the cost of the EDM, and materials are more readily available.
Figures can also be made by forming pure nickel sheet around cut-out molds. I have cut out wooden figures of birds, fish, shamrocks and many other figures to form the nickel around. This is obviously inexpensive and requires no outside work like using the EDM or laser cutting does. The nickel form is placed in a square tube and powdered steel is used to fill the tube. Special shapes may also be forged and placed in these billets, using whatever it takes to get the desired effect.

When using powdered steels, you must compact the powder as much as possible before sealing the tube. Vibrating the tube works well to help the powder settle and become as dense as possible. These billets feel soft during the initial forge welding, but after the billet has been reduced by about one-third, it will begin to feel solid.

Certain powders move at different rates while being forged, so experience is critical in forging billets with little distortion. Start with something simple and pay attention to how things move inside the billet and it will not be long until the results will be predictable.

Powdered steel has not been used in damascus steel for long. Steve Schwarzer pioneered its use in the early 1990s, and in 1999, I acquired some powdered steel from Devin Thomas and Ed Schempp, making several knives with powdered steel damascus for the BLADE Show that summer. Since then, its use has become widespread and the impact on the Damascus steel world has been tremendous. In my opinion, we have only scratched the surface and the possibilities for its use are limitless.

Conclusion

If the damascus bug has not bitten you at this stage, you must be immune. If you are infected, I welcome you to a wonderful world.

The information shared here has been gathered through personal experience and sharing with some of the world’s greatest blade smiths. I can never fully express my appreciation to Fogg, Schwarzer, Thomas, Schempp, Daryl Meier, Hank Knickmeyer, Al Dippold, Rob Hudson, and the three other original members of the “Montana Mafia,” Shane Taylor, Barry Gallagher and Wade Colter. Each one has contributed tremendously to my success as a blade smith, and without them I am sure I would not be writing this article.

Out of respect to the above-mentioned blade smiths, I ask you to take this information and build upon it. Share what you learn and give credit to those who help you along the way.