Discover what pot metal is. Learn about its frustrating properties, and find out if you could tackle a pot metal welding project. Find out how it originated, along with its properties and what projects commonly use this type of metal.
Uses for Pot Metal
There are many different types of metal that you may work with as a welder. Whether you weld professionally or it is just a hobby, you may at some point come across pot metal. This type of metal is much different than other metals you may be used to working with. If you don’t understand its properties, it can be difficult to use.
There is a lot to learn about this type of metal if you want to use it. This includes exactly what it is, what makes it unique and what is good about it. You also may benefit from learning about how it is commonly used. The following is an overview of pot metal that should help clear things up for you if you want to work with it, or if you come across it on a welding project.
What Is Pot Metal?
Pot metal is a cheap metal that is typically a mixture of metals in which each has a low melting point. It is known for its inferior quality. It is generally reserved for projects requiring the use of inexpensive metals. The name comes from its origins. In automotive repair shops , scrap metal used to be gathered and put into a pot so it could be melted for use on patch jobs or other small jobs as needed.
Some people call pot metal monkey metal, die-cast zinc or white metal. Typically, this type of metal includes:
It can really include scraps of pretty much anything, but typically, it is largely zinc. All the metals are melted together, which alters the properties of each individual metal included in the pot so it has a low melting point and is rather weak. Including too much of a metal such as iron could raise the melting point of the mixture and make it something other than a true pot metal.
Pot metal is available to buy, but you can also make your own. Foundries are a good source if you are looking to buy scrap metal. The issue with pot metal made from scrap metal is that it often contains impurities which will lead to problems as you try to work with it. Making your own allows you to control the blend and reduce impurities.
Because pot metal is of low quality, it does not age well. It may crack, bend, shatter, pit or distort over time. It is also often filled with bubbles, which make it weak. It may be susceptible to corrosion, as well. Furthermore, it is not ideal for items or surfaces that need to be painted because paint will peel off it over time.
How To Identify Pot Metal
You may come across an unidentifiable metal, or perhaps you come across a project and cannot identify the metal used for it. Due to its mixed nature, pot metal can be hard to identify. Sometimes it looks like another metal if it contains a higher level of a certain metal. So, it may look like that metal, but it won’t have that metal’s properties. This poses a problem. You need to properly identify the metal in order to be able to work with it.
Identifying pot metal can be tricky. If you have a true pot metal that is largely zinc, then you can heat it up and watch the color of the smoke. If it is white, then it is likely pot metal. You may also be able to tell because pot metal melting temperatures are pretty low in comparison to those of other metals. You may also weigh the metal. Pot metal is very heavy compared to aluminum, for example. If you are familiar with aluminum, then you may be able to judge this.
Pot metal often does look like aluminum, but there should be clear signs that it is not. Look for a pattern in the finish that would not be present in aluminum. Also, if you see darker areas, this is a good indicator.
The Problem With Pot Metal
Pot metal actually has a few problems, most of which stem from its mixed-metal nature. The first problem that you are likely to notice is that it is not easy to weld it. To begin with, you really need to know the type of metal you are working with, so using a mixed metal makes things difficult. If the pot metal has a high level of zinc, then you really should not weld it at all. Zinc, when welded, releases fumes that can be toxic and make you sick. If your pot metal contains a lot of aluminum, welding is going to be very tough.
In addition, because pot metal has a low melting point, it is very easy to raise the temperature too high and end up with a lump of metal. You may have to use an alternate process to fuse pot metal parts together.
Even if you are able to weld the pot metal, you must be very careful as you work with it. Its soft nature is going to be one of the biggest issues you face.
Benefits of Pot Metal
Not every aspect of pot metal is negative. It does cast well. The process is fast and easy, so it is very commonly used to make items that can be finished in a mold. It also doesn’t require complex tools to work with, and it is easy to cast without special molds.
Pot metal is also very inexpensive, especially when compared to other metals. If it works for your project, it can really help to keep the overall costs down. Plus, it is readily available, so you shouldn’t have trouble getting the amount you need for a project.
Uses for Pot Metal
Now that you know a little about pot metal and how it reacts to welding, you may wonder how you could possibly use it. It actually is used a lot in many different goods. You might be surprised at how often it is found around the home. Because pot metal does not age well, it is generally used for items that are not going to be exposed to rough use or weather. This makes it ideal for use in home goods.
You might find pot metal being used in the kitchen. It is a popular choice for cookie cutters. You have probably seen old, metal cookie cutters. One of their attributes is that they bend pretty easily. You can thank the pot metal for that.
It may be found in the toy box, as toy cars are often made from pot metal. It may even be found in other toys that have metal elements. Using pot metal helps to keep down the cost of these cheap toys.
This metal is also found in fittings used in lower-cost furniture. It may be used in cheap tools and electronic items. Lower-end guitars and other musical instruments may also use it.
In the past, pot metal was used for automotive parts, primarily window cranks. Before electric windows were standard, every car had window cranks to get those windows rolled down. This cheap metal was a great way to add this important function without increasing manufacturing costs.
Pot metal is also very popular in jewelry making. Many artists use it since jewelry does not require a strong metal because it is generally treated gently. It also can be shaped easily, which makes the jewelry-making process faster and easier for the artist.
How to Weld Pot Metal
If you want to try your hand at welding with pot metal or trying to use it in some other way, then you really need to make sure you understand how to work with it. It will not act like other metals you may be accustomed to working with. A wrong move could spell disaster for your project if you don’t treat the pot metal properly.
Pot metal is notorious for being difficult to weld. Its low melting point, combined with the fact that there are mixed metals in it, and that zinc gives off toxic fumes, means you should expect to have some trials when welding it. There are some tricks to the process that will help you to weld it more easily.
First, you need to tig weld this type of metal. As you know, tig welding requires some skill, so you should have the knowledge and equipment to properly weld the pot metal. However, you will find it easiest if you have experience welding aluminum. Pot metal is similar in many ways, so if you can weld aluminum, then you can usually weld pot metal.
As you begin, use low temperature settings and work slowly. Use the same method you would use for aluminum. Keep the heat low so you don’t end up completely melting the piece you are working on. You want to weld in short bursts of about five to ten seconds. You want to let it cool in between. Once it starts to flow, you need to stop and let it cool or you will end up with a mess.
As mentioned above, welding pot metal is not an easy task. Even more accomplished and experienced welders will shy away from it because of the difficulty. Not everyone will find it easy to do, and some welders may never master the task. However, if you want to take on the challenge, you are now armed with what you need to know to at least give it a try.