Best Solder Wire For Electronics Repair

If you are an electronics repair rookie, you might think that all solder spools are alike. But you will promptly figure out that’s far from the truth. Certain options are the best solder for electronics, while others might not completely satisfy your soldering needs.

In this review, you’ll dive deep into the types of solder. I carefully studied the market and picked the optimal offers based on critical parameters.

What type of solder to use?

There are two basic solder types used in electrical bounding – lead-based and lead-free. Basically, the key difference lies in the presence of lead. This parameter defines the melting temperature and spectrum of projects you can work on.

Lead-based solder

Until recent times, lead-based solder has been the common choice for soldering jobs. This alloy is composed of lead (Pb) and tin (Sn). The standard proportion of these metals is 60/40 (Sn/Pb), which delivers a great tensile and shear strength.

Lead solder has a reasonable flowing capacity that allows applying the solder easier. Since this solder type has a lower melting point (361°F), you will expose components to less thermal effect. Besides, when it cools down, it is prone to fewer flaws during thermal contraction and expansion due to a more stable structure.

Using lead-based solder following safety precautions poses no threat to the environment and people. However, there are some health and environmental risks connected with lead solder if it’s misused. Lead is hazardous to the human body when you inhale it with vapors. It also might harm a person who has disposed of the residues inappropriately or failed to wash hands carefully.

Lead-free solder

Lead-free solder doesn’t contain lead, which makes the product eco-friendly. It usually has tin combined with other elements like copper, silver, zinc, indium, and more.

The lead-free solder will melt at a higher temperature (around 417°F), which might not be appropriate for working with components that won’t resist high-temperature exposure. Besides, the lead solder replacement creates stronger bonds. Thus, it makes more reliable joints that are less prone to mechanical fatigue.

Best Solder for Electronics Reviews

Lead-based solders

Kester 24-6040-0027 – best lead-based

This 1-pound lead solder is probably the best stuff that can make soldering easy.

Being 0,03 inches in diameter, this solder is easy enough to manipulate. Because of the alloy composition (60% Sn, 40% Pb), this lead-based solder has a nice melting point (361° F / 183° C), which will help you avoid exposing your board to high heat.

Unlike MAIYUM solder with similar characteristics, this soldering material comes in one sloop size – 1 pound, which might be too much for small projects.

This solder has a rosin flux core, which prepares the surface for soldering and ensures a smoother solder flow. Based on my experience, you do not require additional flux to tackle ordinary projects.

MAIYUM – best budget

MAIYUM lead-based solder is a great solder for small electronics as it has proper wire diameter options (0,02 inches, 0,03 inches, and 0,04 inches) to help you tackle the accurate soldering task. Due to the high content of tin and moderate concentration of lead (63% Sn, 37% Pb), this solder ensures fast and strong soldering.

The announced melting temperature is 361°F, which is similar to Kester 24-6040-0027. But this product melts better at a heat that exceeds 361°F.

I got the utmost satisfaction when testing this solder. It has a moderate content of rosin flux (1,8%), which allowed me to get shiny joints without effort.

Kester 331

Consider this Kester 331 water-soluble solder for circuit boards with oxidation or heavy contamination.

Compared to Kester 24-6040-0027 and MAIYUM, this is a more aggressive solder. Because of the 3,3% of water-based flux, it can remove tarnishes. However, the significant drawback that I found embarrassing is that you’ve got to wash the board to remove residues that might be the reason for corrosion when left.

This solder flows perfectly and melts easily. Because of the 63% Sn, 37% Pb composition, it works under low temperatures. It is applicable both for small and projects due to the optimal 0,03 inch-wire diameter.

Lead-free solders

Mandala Crafts – best lead-free

The Mandala Crafts lead-free solder is made of 99% tin, 0,3% silver, and 0,7% copper. Thanks to 2% rosin flux, solder effortlessly flows over the elements without leaving any corrosion-provoking residues. Unlike lead-based Kester 24-6040-0027, this alloy melts under a temperature range between 419°F to 428°F, which is pretty high.

The wire gauge selection is wide: 0,01; 0,02; 0,03; 0,04; and even 0,06 inches. It also comes in different weight options: 1,8 ounces and 3.5 ounces.

However, mind that the solder will take a copper color once you apply it and the joints. It made no difference to me, but if you are concerned about the look of joints, then copper-based solder is probably not for you.

Enersystec

Enersystec is a budget-friendly lead-free solder made of a mix of 99% tin, 0,7 % copper, and 0,3% silver.

This solder is resistant to heat fatigue and oxidation while delivers perfect thermal and electrical conductivity. Its melting point is 419°F, which is similar to the Mandala Crafts product. However, the flux content is higher (2,5%), which enhances the flowability and cleaning properties of the solder.

What I noticed is that this solder produces less smoke and odor during the soldering process. But what is more important is that it sticks well, even though the temperature should be more than 419°F to ensure quick soldering.

AUSTOR

This AUSTOR lead-free solder for electronics works great for many soldering projects.

Being composed of 99% tin, 0,7 % copper, and 0,3% silver, it offers excellent control during the soldering process and strength when it cools down.

Besides, it is stuffed with rosin flux (2,5%) to deliver enough wetting as you work. It comes in several wire diameter options – 0,02; 0,03; 0,04; and 0,06 inches.

I should admit that the smell of this solder is much better compared to Kester 331. But considering that it is free of lead, that’s not a big surprise. The solder melts between the announced temperature range – 425°F. However, you should increase the soldering iron temp if you got used to lead solders like Kester 331 as this one requires more heat.

How to choose solder for electronics

If you are a complete newbie in the soldering and electronics repair industry, you might think that any spool will do as a great solder wire. But believe me, there are so many things you’ve got to consider to get the right solder for your project.

Type and content of flux in solder

Flux is an agent applied to the surface that is to be soldered. It cleans the metal surface from oxides and other impurities to protect it from oxidation. Flux also improves solder flow.

Some solder products come with flux in the core, while others don’t. So, based on flux content, there are three common types of solder:

• Water-soluble
• Rosin-based
• Flux-free

As the name implies, flux-free solder is free of flux and has a solid core. This is a common choice for DIY projects.

Rosin-based solder is the best solder for electronics repair as it is mildly reactive to oxides and improves solder flow, increasing the soldering process’s efficacy.

Water-soluble flux is stronger than rosin-based one, so it can remove tarnishes much easier. However, it leaves residues that should be completely removed by washing the boards with distilled water to avoid corrosive processes.

Flux content is another factor you should consider. The range of flux content varies from 0.5% to 3% and even higher. Less flux ensures there are fewer flux residues. However, the lack of flux will make soldering more complicated. So, it is better to stick with the golden middle and go with the wire with nearly 1.5% flux content.

What diameter of the solder wire to use?

You can find solder wires that are 0,015 inches, 0,02 inches, 0,032 inches, 0,04 inches, 0,062 inches, and more.

The main principle reads that the thinner the diameter of the wire is, the more precise work you’ll be able to perform. Thus, thin solder wire is suitable for small and single-strand projects, while the thicker one will do for larger elements and jobs that require creating joints for multiple components.

The most acceptable wire diameter for electronics is between 0,015-0,04 inches, depending on the type of device you are repairing.

How much solder do I need?

This might catch you off guard, but it turns out that solder for audio cables and other devices has a shelf life. Lead solder can be used within 6 months after the manufacturing date, while you should dispose of lead-free solder after 1 year since it has been produced.

With this in mind, you should consider the spool size when buying solder to spend your costs wisely. If you use solder for minor repair projects once in a while, go with the smallest spool size (2, 4, or 5 ounces). In case you are seriously involved in soldering, a 1-pound spool is the smartest choice.

Safe soldering checklist

• Wear protective stuff like gloves, glasses, and a mask, especially when working with lead-based solder.
• Ensure you work in a well-ventilated area to avoid exposure to fumes.
• Do not come in contact with lead solder. Wash your hands with warm water and soap if you accidentally touched the soldering material.
• Mind that rosin flux fumes might be harmful and be the reason for serious respiratory issues, so avoid inhaling them.
• Keep electric wires and easy-inflammable objects away from the soldering iron.
• Do not place a heated soldering iron on the working surface. Always put it back in the base.
• If the soldering iron drops, let it fall on the floor. Do not try to catch it with your hands. Pick it when it reaches the flooring.

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