Making and Using AIM Solder

Although soldering, the process of joining together metallic materials by melting and manipulating an alloy to fill the joint space, has a slew of modern day applications, it has actually been in use for nearly 5,000 years. There is evidence that ancient Sumerian swords and other weapons from around 3,000 BC were made by soldering different metal components. It has also been used throughout history in making jewelry, cookware, and stained glass, among other things.

What exactly is solder?

Firstly, it is important to differentiate soldering from welding. Soldering is not the same as welding because welding involves melting the pieces of metal you are joining. In contrast, soldering requires the melting of a filler metal (alloy) to bridge the gap, but does not involve thermal manipulation of the other metal components that are being joined. Therefore, the filler metals that are utilized in soldering must possess a lower melting point than the other elements. Conventional soldering usually incorporates lead into the solder mixture. However, increased awareness about environmental protection has made lead a less popular choice. The three main types of soldering are soft soldering (often involving tin/lead alloy), silver soldering (silver alloy), and brazing (brass alloy).

What industries is it used in?

AIM solder is used in a number of industries including electronics, plumbing, jewelry, metalwork, canning, stained glass, fishing, radiator, automotive, and ammunition industries. Soldering is useful in products that require strong but potentially reversible joining of metal parts without damaging the structure of the components. Electronic work often includes soldering because the low melting point of solder means delicate circuits aren't damaged by heat, and solder mixtures are generally good electrical conductors.

How to make solder (alloy)

Solder is available in a range of different alloy mixtures. The ideal alloy mixture will depend on your intended application. For instance, 60/40 and 63/37 tin and lead alloys have a relatively low melting temperature (meaning they require low heat) and are often used in PCB or stained glass assembly. There are also 50/50 Aquasol and Econosol alloys which are used for plumbing purposes since lead cannot be used in plumbing due to its toxicity. Some tin solders contain less than five percent tin and are used in instances where temperatures can exceed 250°F.

It is possible to actually make your own tin/lead solder alloy, although precaution should be taken to avoid burns and lead poisoning. First, you should weigh out 1g each of tin and lead. Use a crucible to melt the lead and add some carbon powder to prevent formation of a film on the top surface. Next, add the tin and stir until both metals are molten. Pour the molten metal into casting sand or a ceramic tile and wait for it to cool. After it has cooled completely, you can test the integrity of the alloy's hardness, density, and melting point by scratching the alloy with lead, comparing the weight of lead and the alloy, and comparing the melting point to that of pure lead. The alloy should be harder, less dense, and have a higher melting point than pure lead. Again, be careful not to inhale fumes from the lead as this could pose a serious health threat.

How to use solder

We've already discussed all of the industries and products that use solder, but how is it actually applied? Soldering is a skill that has to be developed over time. Basically, you use a soldering gun or soldering iron (there are many different variations of these tools commercially available) to heat the alloy until it melts, then manipulate it while it's still molten to solidify a joint. You will need to select a type of solder that is appropriate for your intended application. For instance, you may use solder wire for small electronic work that requires precision and low melting point.

Editor's Note: Written by Steve Ruzumna. Steve is a master distributor for AIM Solder. He has served many industries ranging from radiator, stained glass, industrial and jewelry.

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