How to Connect a Brass Tube to a Brass Sheet

Preheat any thick sections of the metal at the point of the intended join with a preheating furnace. This step will reduce warping and blowholes in the weld, which may occur because the zinc in brass has a far lower melting point than that of the other components of brass. If the project is too small to warrant a preheating furnace, the torch itself can be used to gently heat the base metal.

Combine braze-welding boric acid flux with water to make a thick paste, and spread it with a wooden paddle on both pieces of brass at the place of the intended join.

Mix acetylene and oxygen to form the incendiary gas in a welder. This mixture will create an oxidizing gas that will reduce the tendency of zinc to vaporize and weaken the brass.

Start the flame of your welder, and carefully apply heat to the surfaces you plan to weld until a thin, white-hot layer of zinc begins building on the molten metal. Take care to prevent the brass from becoming white hot, which impedes the flow of the flux.

Allow the flux to work for a moment or two, then begin melting a silicon bronze filler rod to make the beading to join both pieces of brass. Press the pieces firmly together using a forehand technique.

Let the brass cool in a safe, well-ventilated space; slower cooling times will reduce the probability of a brittle join.