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Damascus steel, renowned for its durability, unique patterns, and a history steeped in myth and legend, represents one of the pinnacle achievements in metalworking. Among the contemporary artisans who have mastered this ancient craft, Bertie Rietveld stands out for his innovative and exquisite Dragon Skin Damascus steel. Rietveld, a South African blacksmith with a global reputation, has redefined the aesthetic and functional standards of Damascus steel through his unique pattern, aptly named ‘Dragon Skin’ for its striking resemblance to the mythical creature’s scales.
Nebula Damascus Steel, a marvel in metallurgy, stands as a testament to the fusion of artistry and precision in modern blacksmithing. Blacksmiths, through a complex process of layering, welding, and acid etching, coax out intricate designs that ensure no two pieces are ever alike. Nebula Damascus is more than just a pattern; it’s a piece of celestial art in the palm of your hand.
Bertie Rietveld, a name synonymous with innovation and mastery in the world of custom knife making, embarked on his journey in the small, picturesque town of Heidelberg, South Africa. From an early age, Rietveld’s fascination with metal and fire was evident, leading him to forge his first knife as a young man. His passion quickly turned into a vocation, as he honed his skills and delved deeper into the art of blacksmithing. Rietveld’s career catapulted to international acclaim with his unique and breathtaking Damascus patterns, particularly the renowned Dragon Skin and Nebula Damascus. His work has not only redefined aesthetic standards in knife making but also earned him numerous awards and recognition from prestigious institutions.
In the realm of custom knife making, the crafting process of Bertie Rietveld’s Dragon Skin Damascus is a meticulous ballet of fire, metal, and sheer skill. Rietveld employs a series of specialized techniques that set his work apart. His approach involves precise temperature control, ensuring that each metal part bonds perfectly without compromising the steel’s integrity. The distinctive pattern emerges through a careful process of acid etching, revealing the forged canister steel’s intricate layers. Rietveld’s workshop is a sanctuary of traditional anvils and hammers, alongside modern power hammers and hydraulic presses, each tool playing a crucial role in transforming raw steel into a Dragon Skin Damascus.
Before initiating the heat treatment of a Dragon Skin Damascus blade, ensure its alignment is perfect. Address any deviations by straightening the blade while it remains pliable, as heat treatment will not rectify bends. Begin by preheating the furnace to a temperature range of 900-950°C (1652-1742°F). Once the blade is positioned inside, wait for the furnace to reach the desired temperature again before proceeding to quench the blade in a medium or fast-acting quenching oil. While quenching, avoid lateral movements as this could introduce cooler oil to one side of the blade, increasing the risk of warping. Vertical movements within the oil are permissible.
Following the quenching process, temper the blade to enhance its durability. For robust blades, temper at 270°C (518°F) for one hour, and more refined blades, a slightly higher temperature of 280°C (536°F) for the same duration is advisable. If warping occurs during the heat treatment, the steel can be softened for correction. Accomplish this by allowing a slow cool down within the heat treat furnace, typically around 650-700°C (1202-1292°F). Alternatively, gently heat the spine with a small torch for manual straightening, though be mindful that this may affect the blade’s final appearance.
The coloring of Dragon Skin Damascus steel involves a process similar to traditional hot bluing, requiring a stainless tank equipped with a propane burner to regulate temperature. An accurate thermometer is crucial to monitor the temperature throughout the process. The necessary chemicals include:
Adjust the quantities based on the tank size, and add the chemicals gradually as they can significantly increase the solution’s temperature, especially Sodium Hydroxide. Ensure the tank has high sides to prevent overflow during boiling or foaming. Mark the original water level for future reference, as evaporation occurs during the process.
Suspend the knife blade in the tank using stainless wire, ensuring it doesn’t touch the sides or bottom. Occasionally reposition the blade to ensure even coloring, as temperature variations within the tank can affect the outcome. Initiate the process at approximately 100°C (212°F), with boiling typically starting between 110°C (230°F) and 120°C (248°F). Carefully add water if needed, but proceed slowly due to the violent reaction with the hot solution.
Monitor the coloring closely by frequently inspecting the blade, as the hues can change rapidly. Desirable colors usually emerge between 120°C and 130°C (248°F and 266°F). Dragon Skin Damascus Steel is particularly receptive to coloring, producing a range of vibrant greens, purples, and reds. Eventually, the steel will darken to blue and then black before turning brown with rust.
The chemical mixture remains effective unless overheated but requires replacement once colors appear less vivid. A fine satin finish of 1200 grit provides the best surface for coloring, as etched surfaces darken without much color, and polished surfaces yield a different color spectrum. After use, securely close the tank to prevent animals from accessing the solution, which is highly alkaline and can cause severe burns. Always use protective gear, including a face shield, respirator, and rubber gloves. Rinse the finished piece in water and apply a penetrating oil like Q20 for protection. Note that this steel type isn’t as structurally robust as layered Damascus, so avoid designs with thin, delicate points.
The chemical process described above is hazardous and requires cautious handling. It is imperative to always wear a full-face shield and rubber gloves when interacting with these substances. If you are not thoroughly acquainted with the chemicals, their properties, and the essential safety protocols, do not attempt this process. Instead, entrust your blade to a qualified professional, such as a gunsmith, for coloring. Bertie Rietveld expressly disclaims any liability for accidents, injuries, or losses that may occur as a result of using these chemicals or following the provided instructions. Your safety is paramount; proceed with utmost caution and awareness.
When working with Dragon Skin steel, which is forged rather than rolled like conventional steel, it’s essential to follow certain guidelines to maximize the potential of the material. Here’s how to ensure optimal use of the steel:
Blade Positioning: Align the blade so that its cutting edge is as distant from the bar’s sides as possible. This positioning minimizes potential weaknesses in the blade’s most critical functional area.
Orientation: The blade’s back end should align with the bar’s end, with the tip pointing inward. This alignment ensures efficient use of the steel and proper grain orientation.
Pre-Heat Treatment Thickness: Maintain the cutting edges at approximately 1mm thickness before heat treatment. This thickness allows for the final grind post-treatment, ensuring the edge doesn’t overheat and lose its integrity.
Refer to the accompanying diagram for a visual guide to the above layout recommendations.
As a craftsman, I dedicate significant care to preparing and forging the steel, ensuring its cleanliness, and minimizing visible flaws. However, it’s important to remember that all Damascus steel, including Dragon Skin, is a handmade product. Adhering to the above guidelines is crucial for achieving the best results.
The steel’s quality is optimal in the middle of the billet, so position the more delicate parts of your design accordingly, away from the edges. While the steel will be satisfactory in the majority of cases, always strive to leverage the best qualities of the material for an exceptional end product.
Before heat treating Nebula Damascus blades, confirm their straightness. Heat treatment won’t correct any existing bends, making this step crucial. Preheat your furnace to 900°C (1652°F) and insert the blade. Once the furnace stabilizes at the target temperature, swiftly remove the blade and quench it in a medium or fast-acting quenching oil. As Nebula Damascus is essentially a basic carbon steel, it doesn’t require prolonged soaking at the temperature. Typically, the blade should spend less than 10 minutes in the furnace. For an oxygen-reduced environment, consider placing a charcoal briquette at the furnace’s bottom rather than using foil packets, as quick removal is key for effective quenching.
During quenching, you may move the blade vertically, but avoid lateral movements. Sideways motion introduces colder oil to one side of the blade, likely leading to warping. Post-quenching, temper the blade at 200°C (392°F) for 30 minutes. While Nebula Damascus is generally stable, if warping occurs during heat treatment, you’ll need to anneal, straighten, and re-treat the steel, which might affect its quality. Anneal by heating to 650-700°C (1202-1292°F) and allow to cool slowly, either in a container of vermiculite or in the furnace overnight. Alternatively, you can carefully heat the spine with a small torch for straightening, though this may leave marks during coloring due to changes in the steel’s structure.
For optimal results with forged Nebula Damascus bars, position the blade so that the cutting edge is as distant from the bar’s sides as possible, and align the blade’s back end with the bar’s end, with the tip facing inward. Before heat treatment, keep cutting edges around 1mm thick, and perform the final grind afterward, ensuring you don’t overheat the edge. Refer to the provided diagram for a visual guide to these layout tips.
The coloring process for Nebula Damascus steel closely resembles traditional hot bluing methods and requires a stainless steel tank with a propane burner to achieve the necessary temperatures. Essential for monitoring the process is an accurate thermometer. The chemicals needed include:
Adjust the recipe based on your tank’s size, ensuring the solids dissolve completely in the water. Introduce the chemicals gradually, particularly the Caustic Soda, to manage the significant rise in temperature. If the mixture becomes too hot, pause and allow it to cool before continuing. Construct the tank with heightened sides to prevent overflow from boiling or foaming. Mark the tank’s initial water level to replenish it to the same point in future sessions, compensating for evaporation.
Suspend the blade in the tank using stainless wire, such as TIG welding wire, to ensure it hangs freely without contacting the tank’s sides or bottom. Periodically adjust the blade’s position to ensure even coloring. Start heating the tank and introduce the blade at about 100°C (212°F). Boiling typically begins between 110°C (230°F) and 120°C (248°F). If the boiling temperature exceeds this range, cautiously add water, bearing in mind the potential for a violent reaction. Monitor the color changes closely, especially as the temperature reaches 120°-130°C (248-266°F), where the most vibrant colors emerge. The steel transitions through various hues before ultimately turning dark blue, then black, and finally, brown with rust.
For an optimal finish, a fine satin 1200-grit surface is recommended. Alternatively, for a striking effect, etch the steel deeply with Ferric Chloride to elevate the nickel and then color it, producing deep black steel with shiny nickel highlights. Maintain the coloring solution’s effectiveness by avoiding overheating and replacing it when colors begin to fade.
Upon completion, secure the tank to prevent accidental access, as the solution is a potent alkaline and poses severe burn risks. Always employ protective gear, including a face shield, respirator, and rubber gloves. Rinse the finished piece in water and apply a penetrating oil like Q20 for protection. Remember, Nebula Damascus steel is not as structurally robust as layered Damascus, so handle thin blades with delicate points cautiously and consider avoiding such designs.
The described chemical process and associated materials are HAZARDOUS and require meticulous handling. When working with these chemicals, always wear a full-face shield and rubber gloves. If you lack a comprehensive understanding of the chemicals, their properties, and the mandatory safety protocols, refrain from undertaking this process. Instead, entrust your blade to a qualified gunsmith for coloring. Bertie Rietveld explicitly disclaims liability for any accidents, injuries, or losses that may arise from the use of these chemicals or from following the provided instructions. Prioritize your safety and ensure you’re well informed and equipped before considering this process.
The art of crafting Damascus steel, particularly the exotic Dragon Skin and Nebula patterns, stands as a testament to the fusion of ancient tradition and modern innovation. Bertie Rietveld, with his exceptional craftsmanship and dedication, has not only preserved the legacy of this ancient art but has also elevated it to new heights. His unique techniques and the intricate beauty of his work underscore the limitless potential of human creativity and technical skill. As we reflect on the mesmerizing patterns of Dragon Skin and Nebula Damascus, we are reminded of the beauty that emerges from the perfect blend of fire, metal and the human spirit. The journey through the world of Damascus Steel is an ongoing saga of innovation, artistry, and the relentless pursuit of perfection.
Authors: Aleks Nemtcev | Connect with me on LinkedIn and Bertie Rietveld.