Zink-aluminum welding rods - cheap technique to fabricate applicable repairs

You heard now about aluminum welding rods that are used to repair die-cast, zinc and aluminium. Aluminum can be joined by brazing, but it is not an easy task (more hear). The main factor of the material usefulness is a low enough temperature (about 380 degrees Celsius) to avoid recrystallizing the base material. Aluminum welding rod is stronger than base aluminum alloy.

Zn-Al welding won't work on ferrous metals except galvanized steel, they also don't stick to Stainless steel or 2000 grade aluminium, mazac and pewter. You need to scrupulously clean aluminum with wire wheel and solvent from oxidized metal, it should be shiny. Heat needs to be applied before welding and carefully whilst prodding/scratching around the weld area with the welding rod to watch for it starting to wet the surface.

You can use any heat source, but if the surface is large (like a boat bottom) or the joint is on heavy component, oxyacetylene or mapp torch are much better. Heat the aluminium parts hot enough for the rod to flow without the aid of the flame, thoroughly tinning the surface. In any case don't place the rod onto the flame, or the weld won't be strong enough.

392°C working temperature makes aluminum brasing rods the easiest method of aluminium repairs. For the repairs there is no need in use TIG welding machine, small, cheap and portable gas torch is enough. Because it's more like soldering, joints are clean and free from slag. Zn-Al welding rods can be used with Oxyacetylene, Map/Pro hand torch and works with almost all non-ferrous metals.

I'll give you some final advices. It's great if you spend time on pre-tinning. Tin both parts separately. Remove pores and bubbles with brush, in this case you can use direct flame on alloy. With sides thoroughly tinned, assemble the details and flow in enough rod to fill the vee. The use of appropriate flux paste will make your results better, but you should choose the right one which corresponds to the working temperature (aluminum welding rods).