Soldering irons and soldering guns come in a range of sizes and configurations—each one tailored to a specific job or application. (Image/OnAllCylinders)

Whether it’s for a holiday or birthday, this Tools Under 30 Dollars Gift Guide Series shows you important, yet somewhat uncommon, tools that any gearhead would want.

Today, let’s talk about Soldering Irons & Soldering Guns.

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Knowing how to solder is a pretty handy skill to have if you’re a gearhead. It can help you make error-proof, reliable electrical connections—whether you’re doing an EFI conversion or just installing a bangin’ stereo.

If you’re unfamiliar with what soldering is, think of it as essentially “gluing” an electrical connection together using a melted metal alloy called solder. And you’ll commonly see soldering used to join together electrical wires, finish electrical connectors or terminals, and to connect components on a printed circuit board (PCB).

Solder itself typically comes in a solid wire form, often coiled within handy tube dispensers. (Image/OnAllCylinders)

What’s the Difference Between a Soldering Iron & Soldering Gun?

So, for the purposes of this story, we’ll focus on the two most common types of soldering tools: soldering guns and soldering irons.

What’s the difference? It boils down largely to the jobs they’re used for—we’ll give some basic pros/cons below, along with some standard use cases.

Soldering Guns

Thanks to their ability to heat up quickly, soldering guns can be good for occasional, garage use. (Image/OnAllCylinders)

Soldering guns are useful because they can heat up quickly, using a trigger mechanism to allow you to activate them only when you’re ready to solder. Though due to their large size and typically broad heating tip, they’re not well suited to precise applications, like soldering on a PCB or in close quarters to sensitive electrical parts.

Yet soldering guns are really handy for soldering wires together or building/modifying a wiring harness—especially when it’s on the vehicle.

Soldering Irons

Soldering irons tend to be more precise, with finer heating tips that allow you to make more targeted solder applications. But irons take a while to heat up and, as a result, they typically need to be on full-time, to ensure they’re ready when you need them. Not a big deal if you’re at a workbench, but tricky if you’re shoulders-deep in an engine bay.

A soldering iron’s precision can be vitally important though, and many feature adjustable temperature settings to allow you to solder contacts without excessive heatsoak into surrounding electrical components. They’re also ideal for applying solder into crowded chassis and PCBs.

Need to work inside a tight spot and around delicate components—like a vintage tube amplifier chassis? A soldering iron offers vital precision. (Image/OnAllCylinders)

How To Splice & Connect Wires Via Solder

While soldering has plenty of applications outside of this quick demo below, we wanted to show you a very basic look at the soldering process in a typical use case: connecting two wires together, also known as “splicing.”

1. Strip Away the Wire Insulation

Using our old pal the wire stripping tool, we expose the stranded wire underneath. (Image/OnAllCylinders)

2. Connect the 2 Wires by Splicing the Stripped Ends

Hemmings has a good write-up on some common splicing methods. This was a relatively short run of wire for a tube audio amplifier that demanded a truncated version of the “linesman splice.” (Image/OnAllCylinders)

3. Touch the Iron or Gun Tip to the Joint Before Applying Solder

This is a key step. With the iron or gun already hot, touch the tip to the exposed wires in the joint for a few seconds. This allows the wires themselves to heat up, ready to accept solder. Then, you take your soldering wire and touch it to the superheated joint—note the iron and solder wire are not touching. Done properly, the solder will flow into the nooks and crannies within the joint, for a strong electrical connection. (Image/OnAllCylinders)

4. Insulate the Connection

You’re not done yet. Make sure to insulate the solder connection you just made, to prevent shorting and corrosion. You can either wrap the joint in specialty electrical tape or use heat shrink tubing. (Image/OnAllCylinders)

Selecting the Right Soldering Iron or Gun

While soldering irons and soldering guns can get expensive quickly, there are plenty of affordable options that’ll let you learn and hone your soldering technique. And given how versatile a skill like soldering can be, giving someone a soldering iron or soldering gun can be a pretty thoughtful gift—especially since you can likely find a basic soldering iron or soldering gun for under 30 bucks.

Many soldering irons use interchangeable soldering tips as well, so you can use the one best suited to the soldering job at hand. (Image/OnAllCylinders)

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Author: Paul Sakalas

Paul is the editor of OnAllCylinders. When he's not writing, you'll probably find him fixing oil leaks in a Jeep CJ-5 or roof leaks in an old Corvette ragtop. Thanks to a penchant for vintage Honda motorcycles, he spends the rest of his time fiddling with carburetors and cleaning chain lube off his left pant leg.