Eduardo Berardo
Eduardo Berardo JS
- Joined
- Jan 26, 2009
- Messages
- 331
Recently I and my friends Ricardo Vilar (JS) and Rodrigo Sfreddo (MS) were in Milano Knife Show. There we three have received many accolades for high contrast and definition of our damascus. We realize that bladesmiths of Europe were not a step in the treatment of damascus that caused it to get very dark, high-definition: the immersion in phosphate and manganese.
My friends Vilar and Sfreddo told me that a large percentage of North America bladesmiths no did the immersion with manganese phosphate.
Recently I have received some emails from bladesmiths wondering how I could make my damascus black and high definition. Thus I decided to describe my whole process of treatment of damascus. I'm not pretending to teach people because certainly some must have procedures that result in better scores than those I can. The idea is just to disclose the custom cutlery has an evolving technique. Bladesmiths want to help others as I have received valuable guidance from excellent bladesmiths. Let me clarify that this process is essentially what we do in Brazil with some peculiarity of mine. I held with my friends bladesmiths more experienced.
I'll try to explain in detail all my treatment of damascus. Maybe the translation leave any questions, please let me know if you do not understand something.
1) Acid attack:
After finishing all trim pieces that make up the knife (sanding to up 320 grit sandpaper) I do a complete cleaning with liquid detergent. The attack is made with ferric perchlorate.
The attack time and the proportion of the acid solution in water vary. The lower layers of steel in damascus, the weaker the acid solution and the slower the attack. I'll try to explain with an example:
a) For a blade in standard ladder with about 360 layers I would attack with a weak acid solution that would last about 90 or 100 minutes.
b) For a blade in the same pattern with about 160 layers with the attack would be a more concentrated solution, which lasted about 40 minutes.
This is just one example. The important thing is to understand that the smaller the thickness of its layers of softer steel will be the acid attack. This is because a very aggressive attack on a plate with thin layers of damascus steel will take the definition of these layers. When the acid solution is too strong it will also attack the nickel steel (15N20) and will make a perfect setting between the layers. Here in Brazil we say "blurring the damascus".
Of course, during the whole process of attack should check the progress from time to time not only building on the clock.
After the etching I cleans the piece with a sanding with 1200 and a toothbrush to clean the layers in low relief.
Then comes the step that makes my damascus become quite black.
2) Immersion with manganese phosphate:
I prepare a solution containing 10% manganese phosphate and 90% water. Heat this solution between 95 and 98 ° C (controlled with thermometer immersion) in an iron container (can not be stainless steel). As the solution reaches the desired temperature I dive a steel wool (for washing pots) tied on a wire and keep the shackles for an hour (always keeping the temperature within the range cited). After an hour I pull the steel wool (it dissolves in the water) and I can make the immersion of the pieces of my knife. The shower lasts 80-20 minutes. Depends on the evolution of the reaction. The reaction chemistry of adhesion of the manganese phosphate produces bubbles like champagne. When the bubbles stop is a sign that the reaction is over and you can remove the piece. PS: In the next pieces that you are doing the dumping is no longer necessary to make the "activation" with steel wool for an hour. Just heat up between 95 and 98 º C and do the dip. The same solution should last for more than 15 knives. Completed immersion fofato the manganese will be deposited throughout the blade. Sand the entire piece thoroughly with sandpaper grit 1200. This sanding will remove the manganese phosphate which is deposited only on the layers of nickel steel (in my case 15N20) as this is in high relief. Already the layers of carbon steel (in my case O1 or VND) remain covered by manganese phosphate as the acid attack left them in low relief. This gives the appearance of black in my damascus. After that just make the final step: polishing.
3) Polishing:
Initially I do a hand-polished with 2000 grit sandpaper or 2500. Est process must be very careful not to remove the manganese phosphate. Once you get a good result at hand I do with a polishing cloth wheel (with mass polishing). This polishing is dangerous. The wheel should feel very gently steel for not remove the manganese phosphate.
If the phosphate is removed from the immersion in any area can be rebuilt without any problems. For patterns damacus with large black areas requires more care.
That's it. The practice and experience of each will yield excellent results.
I sincerely hope to have helped and I am at your disposal for any questions.
God blesses,
Eduardo Berardo.
My friends Vilar and Sfreddo told me that a large percentage of North America bladesmiths no did the immersion with manganese phosphate.
Recently I have received some emails from bladesmiths wondering how I could make my damascus black and high definition. Thus I decided to describe my whole process of treatment of damascus. I'm not pretending to teach people because certainly some must have procedures that result in better scores than those I can. The idea is just to disclose the custom cutlery has an evolving technique. Bladesmiths want to help others as I have received valuable guidance from excellent bladesmiths. Let me clarify that this process is essentially what we do in Brazil with some peculiarity of mine. I held with my friends bladesmiths more experienced.
I'll try to explain in detail all my treatment of damascus. Maybe the translation leave any questions, please let me know if you do not understand something.
1) Acid attack:
After finishing all trim pieces that make up the knife (sanding to up 320 grit sandpaper) I do a complete cleaning with liquid detergent. The attack is made with ferric perchlorate.
The attack time and the proportion of the acid solution in water vary. The lower layers of steel in damascus, the weaker the acid solution and the slower the attack. I'll try to explain with an example:
a) For a blade in standard ladder with about 360 layers I would attack with a weak acid solution that would last about 90 or 100 minutes.
b) For a blade in the same pattern with about 160 layers with the attack would be a more concentrated solution, which lasted about 40 minutes.
This is just one example. The important thing is to understand that the smaller the thickness of its layers of softer steel will be the acid attack. This is because a very aggressive attack on a plate with thin layers of damascus steel will take the definition of these layers. When the acid solution is too strong it will also attack the nickel steel (15N20) and will make a perfect setting between the layers. Here in Brazil we say "blurring the damascus".
Of course, during the whole process of attack should check the progress from time to time not only building on the clock.
After the etching I cleans the piece with a sanding with 1200 and a toothbrush to clean the layers in low relief.
Then comes the step that makes my damascus become quite black.
2) Immersion with manganese phosphate:
I prepare a solution containing 10% manganese phosphate and 90% water. Heat this solution between 95 and 98 ° C (controlled with thermometer immersion) in an iron container (can not be stainless steel). As the solution reaches the desired temperature I dive a steel wool (for washing pots) tied on a wire and keep the shackles for an hour (always keeping the temperature within the range cited). After an hour I pull the steel wool (it dissolves in the water) and I can make the immersion of the pieces of my knife. The shower lasts 80-20 minutes. Depends on the evolution of the reaction. The reaction chemistry of adhesion of the manganese phosphate produces bubbles like champagne. When the bubbles stop is a sign that the reaction is over and you can remove the piece. PS: In the next pieces that you are doing the dumping is no longer necessary to make the "activation" with steel wool for an hour. Just heat up between 95 and 98 º C and do the dip. The same solution should last for more than 15 knives. Completed immersion fofato the manganese will be deposited throughout the blade. Sand the entire piece thoroughly with sandpaper grit 1200. This sanding will remove the manganese phosphate which is deposited only on the layers of nickel steel (in my case 15N20) as this is in high relief. Already the layers of carbon steel (in my case O1 or VND) remain covered by manganese phosphate as the acid attack left them in low relief. This gives the appearance of black in my damascus. After that just make the final step: polishing.
3) Polishing:
Initially I do a hand-polished with 2000 grit sandpaper or 2500. Est process must be very careful not to remove the manganese phosphate. Once you get a good result at hand I do with a polishing cloth wheel (with mass polishing). This polishing is dangerous. The wheel should feel very gently steel for not remove the manganese phosphate.
If the phosphate is removed from the immersion in any area can be rebuilt without any problems. For patterns damacus with large black areas requires more care.
That's it. The practice and experience of each will yield excellent results.
I sincerely hope to have helped and I am at your disposal for any questions.
God blesses,
Eduardo Berardo.