Joe Kertzman - His Forge Burns Hot for Mosaic Damascus

Devin Thomas draws out a bar on a 150-pound air hammer.

My first exposure to damascus knives was through the book Knives 84. As a new knifemaker, I was most impressed by the knives of Kemal (Murad Sayen), Sid Birt and Hill Pearce. Since I had almost no contact with other knifemakers at the time, forging damascus seemed like an impossible dream.

An article by Wayne Goddard in Knives 86 on welded wire damascus inspired me to try my hand at pattern welding steel. I learned quickly that my wood stove did not get hot enough to weld cable. Twenty years later, I understand quite a bit more about making damascus, although Im still not able to pattern weld steel in my wood stove.

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.

For me, it has been a wonderful journeya journey that continues every day with no end in sight. After learning some of the basic techniques, there are no limits to where the journey can take you. With the basics of forge welding mastered, a blade smith can create new patterns and figures with each new steel billet. This thought has kept me obsessed with damascus for 10 years. The inspiration for new damascus patterns is everywhere; you just have to be open to unexpected influences.

Bernd Munsteiner, a world renowned lapidary, describes design as a personal creative search of the form, the comprehensive and visible expression of an individual which, through becoming aware and recognizing an order, sets the undefined bounds, recognizes chance and eliminates the arbitrary. This applies appropriately to the creation of damascus. Once the maker becomes aware and can recognize the order, creating new patterns becomes a matter of imagination, and the possibilities are endless.

Forge welding damascus can be complicated and there are many factors with potential to make a good weld an impossibility. I once conducted a damascus-making demonstration in Canada and could not achieve a good initial weld on my billet. After several unsuccessful attempts, I noticed a green color to the flame in the forge. After some questioning, I found out that mokume was being made in the forge prior to my demonstration. Some of the mokume had melted in the forge and the copper was contaminating the atmosphere inside the forge. After changing forges, I was able to weld my billet and save face.

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, Im confidant 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.

The author flattens an accordion-style damascus bar on a hydraulic press.

The blade I used to test for my American Bladesmith Society master smith stamp was made of these materials. It easily passed the performance test, which included cutting 1-inch rope in one swing, chopping a 2 4 in half twice, and still shaving hair, and then flexing 90 degrees without breaking. My blade flexed back to about 20 degrees with no cracks or any damage to the steel.

For specialized damascus billets, 1084 and pure nickel can be used, but edge holding is not on par with 1084 and 15N20. For some complicated mosaics, 1084 powder, 1018 powder, pure nickel powder and 4600E powder work well for me. The 4600E powder is similar to 15N20 but has less carbon.

As youve probably deduced, I make an effort to keep my damascus materials as simple as possible. I try to avoid steels that contain chromium, and since eliminating the use of 52100 and 5160 blade steels, my success has increased tremendously. By eliminating as many variables as possible, problems with forge welding are easier to identify.

I have used various propane forges to make all of my damascus steel. My first was built using plans I obtained from Wayne Goddard, and the one that I use now is similar to a Don Fogg design. At hammer-ins, I have used many variations of these forge designs, and all have worked well.

As with my philosophy on knifemaking, I like my forge to be simpleone 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.

Nineteen layers of 1084 and 15N20 are stacked with the thicker steel1084on the top and bottom to keep the thin 15N20 from warping in the heat.

A 19-layer billet is cut into five pieces and readied for a second weld, which will result in 95 layers.

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.