What Can a Soldering Iron Melt?

Electric soldering irons are designed to melt solder, typically an alloy of tin and lead or tin with other metals. High-powered models can produce temperatures up to 540°C (1004°F). But is this temperature enough to melt things than solder?

Let’s delve into the fascinating world of melting with a soldering iron!

Can a Soldering Iron Melt Metal?

Have you ever wondered if you could melt metal using a soldering iron? It all depends on the metal’s melting point.

While a soldering iron could melt some metals with low melting points (like tin or lead), it’s generally not capable of melting most metals. For those, you’d need a melting furnace or kiln or a tool that can generate much higher temperatures, like a blowtorch.

Let’s take a closer look at some popular metals and check whether a soldering iron can melt them or not.

Copper

Soldering irons can’t melt copper as its melting point is (1985°F (degrees Fahrenheit) or 1085°C (degrees Celsius).

Could you imagine if irons were able to do it? Using a soldering iron to join wires, which are usually made of this material, would be impossible. Not to mention that some soldering tips are made of copper, so it would be impossible to use them without melting the tip.

What’s doable is soldering copper to repair pipes or join copper sheets and foils.

To solder copper, the method is similar to when working with glass. You can make solder stick into the copper to be soldered by applying a coat of flux, and that’s it; you are ready to go. It’s important to note that to do this job properly and quickly, you should use a high-wattage soldering iron of between 80 and 100 Watts equipped with a thick or chisel tip.

Aluminum

This metal is called a “cold metal”, and its melting point is as low as 1220.54°F (660.3°C), so, in theory, you could melt a thin layer of aluminum foil using a soldering iron. Melting a piece of aluminum thicker than cooking aluminum foil gets more difficult and almost impossible, as this metal has exceptional heat dissipation capacity, so it would cool faster than it would take for the soldering iron to heat it beyond its melting point.

If you are wondering if it’s possible to solder aluminum, the answer is yes. It can be soldered using flux, as you would do with copper or glass. However, soldering cold aluminum wouldn’t work or create a solid joint; you will need to heat the workpiece to solder it effectively.

Alert: Metals such as copper and aluminum will get oxidized when heated above a limit. This will be a problem when you want to solder these metals later.

Gold

This is one of the metals with the highest melting point (1,947°F or 1064°C), so not only impossible to melt it using a soldering iron, but it’s also impossible to work with gold using one.

To solder gold pieces, you need what it’s called a gold solder or a torch, as solder used to work with this material also has a high melting point, which exceeds the heat a regular soldering iron can produce.

Silver

Silver’s melting point is 1763°F (961.8°C), so melting it using a soldering iron is impossible. If you are wondering if you can use a soldering iron to work with silver pieces, in theory, it’s possible, but it’s not advised because the piece could be stained or damaged when exposed to heat for an extended time.

The best way to solder silver jewelry and parts is to use a torch or a special solder that allows you more control and precision.

Brass

Brass is not a pure metal but basically an alloy of copper and zinc. It has a higher melting point than what a soldering iron can achieve; however, you can solder in a similar way you would solder copper pieces. The only thing to keep in mind is that because of the zinc contained in it, you wouldn’t be able to use regular flux but a special one made to solder brass.

For tasks requiring higher heat, like melting certain metals, butane torches might be a better fit. These tools, while still not capable of melting every type of metal, can reach higher temperatures than their electric counterparts.

Melting Plastic

Soldering irons are great for melting different plastics, making them very practical to repair, weld, and mold plastic pieces. When working with plastic, it’s essential to use enough temperature to melt it without burning it.

Another important thing to consider when using a soldering iron is that these jobs usually take time, eroding and damaging the tip. For this reason, I would recommend using a cheap tip, or at least a different one, when working with plastic. In this way, if the tip gets damaged, you can just replace it, and it won’t affect your soldering iron’s ability to do other tasks properly.

Using a soldering iron with a damaged tip can be very frustrating as it can make your joints look like golf balls.

Please note that only thermoplastics can be effectively welded with soldering iron. Once set, the thermoset plastics are impossible to remold.

Safety:

Some plastics can release toxic fumes when melted. So always wear a mask and it is important to ensure adequate ventilation when melting any type of plastic.

Can a Soldering Iron Melt Glass?

Melting glass using a soldering iron is not possible as glass melts at temperatures much higher than what the most powerful soldering irons can reach. Even glasses made for crafts, called “art glasses,” have a melting point between 1472-1832 degrees Fahrenheit (800-1000 Celsius degrees).

However, you can use a high-power soldering iron for your stained glass projects. You will need a high-wattage soldering iron and a wide tip. The most common way of joining glass pieces is by applying copper or lead foil to the edges of each piece. The copper foil has a strong adhesive so that you can stick to the edges of the glass pieces.

Once you have applied foil to all the parts, you are ready for the following step.

Before joining everything together, it’s recommended to apply flux to the foil covering the edges you want to join. Flux is a liquid that helps remove any oxidation and, as its name suggests, allows the solder to flow better, helping to create a stronger bond between the parts. Once flux is applied, you can then attach the pieces using special solder and a soldering iron.

There are many decorative touches you can add with creativity and by combining the soldering iron and solder with other tools and processes. Since the soldering iron can’t melt glass, it’s a perfect tool to work with it safely.

Exceptions

While the majority of glass types require temperatures far exceeding what a soldering iron can provide to melt, certain types of glasses, such as soda-lime glass and lead glass, have lower melting points and can be worked with at lower temperatures.

However, even these lower melting point glasses typically require temperatures above the range of most soldering irons and would more typically be worked with using a glass kiln or torch.

Cutting Glass with Soldering Iron

Even when you can’t melt glass with it, you can use a soldering iron to cut glass. However, don’t expect it to cut it or create forms as if you were using a hot wire on polystyrene foam (how cool would that be!).

The process takes time and patience, but it’s very interesting, and I want to share it with you.

Cutting plain glass is easy; you can use a pencil-style glass cutter to score the glass and then snap it. However, this method can’t be used for cutting volumetric glass pieces like bottles. For these objects, a soldering iron can be of great help for making great and accurate cuts.

How to Cut a Hole in a Glass Bottle?

The process is pretty simple, think that you want to cut a window on the bottle’s surface or that you want to split it in two. You have to follow these steps:

1. Use a marker to create a guideline with the shape you want to cut.
2. Use a pen-style glass cutter to score a line over the guideline you drew. Don’t apply much pressure to avoid breaking or cracking the bottle, and try to do the least passes as possible.
3. Heat up your soldering iron (any model capable of reaching about 400°C or around 800°F will be enough.)
4. Press the score lines with the side of the soldering iron’s tip, and leave it for 5 to 8 seconds each time. Heating and cooling the glass will start cracking the glass, and the scores will work as a limit so the cracks don’t extend over that limit.
5. Repeat the previous step along the marked line several times until you see a complete see-through gap between the parts or the glass is thin enough to split it by gently tapping the edges of the lines or carefully detaching them using your hand.

A word of caution: Wear gloves and safety glasses when working with glass, as broken pieces can be sharp and potentially dangerous.

To Wrap It Up

Using a soldering iron for melting metals is impossible in most cases. However, using it for what it’s actually designed, which is joining parts together, works for almost all metals using proper solder and flux.

It’s important to highlight that tin-lead solder only works for some stained glass work, as for other applications, you will need to use special solder.

Another interesting thing about soldering irons is that they can be very practical to melt and work with plastic, helping you in multiple jobs. If you are a serious craft lover or do a lot of plumbing, my best advice would be to move on to another tool, like a butane soldering iron or a torch, which will allow you to reach higher temperatures and soldering most effectively. For working with plastics, I wouldn’t change a soldering iron for another tool; besides being practical, it is super practical to use them to melt plastic from time to time.

In conclusion, while soldering irons are primarily designed for soldering, their versatile nature allows for usage beyond just metals. With creativity and understanding of their capabilities, you can use these tools effectively on certain types of plastic and even soft glass, expanding the possibilities for craft, repair, and construction projects. However, always remember the limitations and safety precautions necessary when working with heat and different materials.