The term pot metal (also known as monkey metal, white metal, and die cast zinc) refers to any alloys that are inexpensive, have a low melting, and can produce a cost effective casting. These metals include zinc, copper, tin, lead, magnesium, cadmium and iron. Due to the low melting point of these metals, high tech and costly foundry equipment is not necessary. These alloys are used to make toys, electronic components, some furniture fittings, and many other products including car parts. It is also used to experiment with moldings before a final product is created with more expensive metals. White metals are popular due their cost effectiveness but repairing them is not as easy as producing them. The low melting point which makes the metals inexpensive to use also makes fixing these metals with a blow torch quite difficult.
While using a propane torch to fix broken metals may be difficult, it is not impossible. There are a few things the welder must know before attempting to repair any monkey metal. First the person behind the torch must be trained in its use safely as it can be very dangerous piece of equipment. The operator must know how to operate the supply valve properly to ensure they the use correct temperature but they must first be educated in the exact temperatures for the types of metal with which they are working. After being schooled in proper torch execution for the particular metals the actual repair can begin.
Monkey metals have melting points that vary from 610 to 1600 degrees Fahrenheit which can make repair difficult as it may reach the melting point before the repair is complete. This is especially true when working with aluminum. Recent developments in heated metal repair have produced a product known as Super Alloy 1. This rod melts at 350 degrees Fahrenheit and bonds at about half the melting point of most white metals. Its honey flux turns brown telling the welder when it has reached the proper temperature for bonding. The finished product can be plated or polished and is as strong as the base metal making this an inexpensive and effective way to repair zinc metals with a torch, even for an inexperienced welder.
Pot metal repair was once next to impossible and can still be difficult without the proper tools and knowledge. It is important to first know what kind of metal you are trying to repair so you know what the proper tools for the job are. Research the types of rods best used in your torch for the type of metal you need to repair and make sure the repair is necessary and cost effective; it may be more plausible to sell it as scrap and buy a new item. If the item cannot be replaced easily or cost effectively and repair is the only way to go all you really need is a blow torch and Super Alloy. If you are still hesitant to make the repair at home there are always professional welders that are skilled and knowledgeable in white metal repairs and would be happy to help you for a marginal fee.
This is a guest post by Vit Marks