Forging Brass By Marcus Wedra

Marcus has been fascinated by working with bronze since his early school training. He calls bronzesmithing the king-class of the blacksmithing profession. Especially because bronze as a material with its appearance can be fantastically combined with other metals. Because of the special colour effects.

Some basic facts

Bronze is a copper/tin alloy. Brass is a copper/zinc alloy. The bronze used for forging is actually brass. In German called ‘Schmiedebronze’. It consists of 76% copper, 21% zinc and approximately 3% silicon. There are many types of bronze, each with its own material composition. For example, Naval bronze C46400.

Forging

The melting temperature is around 1,000°C. When processing it is essential to pay attention to the correct temperature. The temperature window within which you can forge is significantly smaller than with steel. And if you forge too cold, the material is brittle. If you forge too hot, it melts away under your fingers. The material melts suddenly and does not give off a 'spark warning' like steel does.

Therefore, it is recommended to only heat the metal in a gas oven for good temperature control. The bronze quickly reaches the right temperature: 'cherry red'. 850°C is the most ideal forging temperature. Little deformation energy is required to get the material into the right shape. A light hammer blow already causes a great deal of deformation.
And the material also cools down very quickly so you have to work quickly. It is therefore important to constantly observe your bronze workpiece carefully during heating and processing.

Deforming and post-treatment

Use the best polished hammers for a smooth surface. Because every imperfection is visible. That property also gives you the opportunity to apply special surface texture. The surface treatment after forging is very labor and time intensive. Oxides can be removed by grinding or with hydrochloric acid. You can then allow the surface to 'age' naturally or you can also apply a beautiful patina using a chemical agent called 'Brünierung' (burnishing or black oxidation).  You can find examples at https://www.instagram.com/marcuswedra/ or https://sculptnouveau.com/ . You can then prevent aging with a layer of lacquer, wax or oil.

Welding and joining

Bronze cannot be fire welded, but it can be TIG welded. The material to be added is special bronze welding rods. Brazing is also a good option for joining parts together.
Tip when welding bronze: Support your workpiece over its entire length because when welding the material becomes as soft as butter and your workpiece will sag under its own weight.

From beginning to end were 12 very engaged listeners from 6 countries with whom experiences were shared and questions answered.

Thanks to our cooperation with ABANA we will be publishing the recording of this Treff in not too far future.

The next Treff is on May 26 by Nick Downing.
Start: 19.00 CEST
Room Open: 18.45 CEST