Damascus – “Pattern Welding”

Pattern welded steel originated around the second or third century when blacksmiths began to use layer welding techniques to incorporate designs into the steel. Early blacksmiths used layer welding to combine hard and soft steels to produce a stronger, more flexible blade. Hard steel, which maintains a sharp edge, was used for the cutting edge while softer; more flexible steel covered the sides of the blade for protection.

Forge welding is the core technique involved in creating Damascus steels. It is a solid-phase bonding technique that uses heat and pressure to make the weld. To make Damascus steels the current method is to stack alternating pieces of steel, each with a contrasting composition, heat the billet in a fire and at the proper temperature apply pressure to make the weld.

Damascus is made by cutting and stacking layers of different steels together and welding them into a solid piece. This piece is called a billet. This billet is then drawn and cut into two or more pieces, restacked and welded. The number of layers in the final billet will depend on the number of distinct layers in the initial billet and the number of times it is folded and welded. Each fold is a geometric progression 4,8,16,32,64,128,256,512 etc.

The beauty of Damascus steel often lies in the contrast between the layers. To get a good contrast between the steels you must use steels of differing compositions. For bright lines, steels that are high in chrome or nickel are often used. For the darker lines simple carbon steels or even low carbon steel may be used. While it is subtle, there are the shades of gray that can be achieved by varying the high carbon steels used.

“The reason for Damascus steel is that it is beautiful. It requires skill to produce and more than any other material we work with; it is capable of reflecting the knowledge, craftsmanship and sensitivity of the bladesmith. It is endlessly fascinating how light plays along its surface; even the most subtle actions are captured in the metal. It maintains a history with the fire and hammer, and because it is so responsive, it has an organic quality that transcends a plain polished surface. It is the next level." - Don Fogg, Master Bladesmith

The patterns on Damascus are the result of twisting, stock removal, or hammering a laminate of different steels.

The basic steps in producing a pattern-welded blade are as follows:

• Begin with several layers of two different alloys
• Stack the layers, alternating the alloys
• Weld the layers into one bar
• Hammer to lengthen the bar and fold
• Re-weld the bar
• Repeat the previous two steps until a bar with the desired number of layers is achieved.
• Create desired pattern by stock removal, punching, or twisting the laminate.

First step is to clean your material. I use copper and nickel silver sheet that I think is 0.020 thick. I buy it in 6 inch widths; I then cut the pieces into 0.75 wide strips, six inches long. I wash them in hot soapy water, to remove any dirt, oil, grease, etc. then I rinse in hot water, and put them into a container and pour straight distilled white vinegar into the container to cover all the pieces. The vinegar will remove any oxides that may be on the surface. If you are not in a hurry, let then soak for 12 hours. I have also stuck them into the oven at 180 deg F for two hours when I was crunched for time. That works well too.

Once they have soaked in the vinegar, rinse them in hot water and dry. But do not touch anything but the edges. I suppose wearing latex gloves would be good, but I guess I prefer all those little cuts on my finger tips from the sharp edges. Any oil from your hands on the mating surfaces could lead to a bad fusion.

Now stack them in an alternating fashion, starting and ending with the nickel silver. NS has a higher melting point than the copper, so you want that on the top and bottom of the billet since that is what is in contact with you pressure plates. Your copper layers basically act as the solder to stick all the NS together.

When you get them all stacked, place them between your pressure plates. My plates are made from 0.5 thick stainless steel plates. They are about 4 x 6 with a hole in each corner to accept 1/2 inch bolts. Tip of the day: stack your billet and get it lined up on a clean surface. Compress one end by pinching with your fingers and wrap a couple layers of masking tape around it (it will just burn away). Do the same with the other end. This will make it 1000 easier to get all the pieces between your plates. My typical billet has 37 layers in it; 19 NS and 18 Cu.

Once your billet is in between the plates, stick it in your shop vise and squeeze the snot out of it and start tightening your bolts. Tighten them as much as possible. If you have a shop press, that might be easier, but you want to get as much pressure as possible on the billet.

Note: The edges of the individual pieces need to be flat. I use a bench shear to cut mine, so they come out pretty flat. If you use hand shears, you will need to flatten out all those little serrations left from cutting. All the pieces need to be touching each other to get a good bond.

Now put the whole thing into the forge and heat it evenly. Don't take it out of the forge, that will let oxidation happen and will ruin the bond. What you are trying to do is get the whole piece up to around 1950 deg F. That is where the copper starts to melt. Go slow, until you know what is going on. Once you start getting to orange color, things start to happen fast.

What you are looking for is the copper to sweat. Little bb's of copper will start to form on the edges of the billet, that is the copper melting into the solodus (sp?) stage. Look for even sweat all over, it is easy to have one part of the billet start to fuse before the other. That is why it is easier to go slow and avoid overheating one area and not having enough heat in another.

I usually get some pea sized globs of molten copper on the billet too, no worries, it is still good. If you watch and go slow, you can see the molten copper on the edges run just like solder does. Once you get good even fusion, turn off the gas, close the forge doors, and let the whole thing cool down to red.

Once red, take out the assembly, undo the bolts, remove the billet, lightly forge, let cool to black, and quench if you are in a hurry.

Now, clean up the billet on the grinder and forge or pattern it as you would Damascus. When forging be careful not to get it too hot and melt your billet. I do all my forging and twisting at a full cherry red heat. It used to take me forever to get the billet to fuse, but after a few times, you know what to look for and now from dead cold to fused is about 10 minutes.

Note: To not have your billet stick to your pressure plates, you can paint them (the plates) with white out or if using SS, heat them in the forge to orange, take them out, let cool to black, repeat. That will let the SS oxidize and the NS won't stick.