How to Weld brass Brass is an alloy of copper and zinc and is a highly useful metal that has many applications. However, it is a difficult metal to weld as copper and zinc have very different melting points (zincs is much lower). Tig welding is the most popular choice for brass, although a strong weld can be achieved with Mig as well. Technically, brass is braze welded due to the lower temperature used. Before you start, find out the zinc content of your particular brass, as this will determine how strong a flame you will need. You will also need to invest in some oxyacetylene gas which will form a protective shield around the brass during the welding process. The oxygen and acetylene gases are stored separately, but are mixed during welding. Make sure you are in a well ventilated area using a respirator or fume extractor. Also ensure that you have the correct protective clothing. Next you will need to mix a flux with water to create a paste, and paint this on to the brass surfaces that you intend to weld. You should buy either a braze-welding flux or one that is specifically designed for oxyacetylene welding. This removes iron oxide. Adjust the acetylene gas to low until you have achieved a strong oxidizing flame that is sufficient enough to develop a coating on the brass metal. This is extremely important, as having enough oxygen will ensure that zinc fumes are not released from the brass. Having too much oxygen will make welding very difficult. Ensure that the welding tip you are going to use is at least one size larger than you would use for steel of a similar thickness. This is because as brass has a high heat conductivity, it will make welding the brass together much easier.