How to Remove Solder without a Solder Pump

Introduction

Removing solder is a necessary skill in electronics work for tasks like desoldering components, repairing connections, or modifying circuits. While a solder pump (also called a desoldering iron) is the most efficient desoldering tool, it is possible to desolder without one in a pinch.

This guide covers simple techniques to remove solder using just a soldering iron and basic tools. With some manual dexterity and proper safety precautions, you can desolder components for electronics work without investing in specialty desoldering kits.

Key Takeaways

• Solder wick and solder braid are inexpensive alternatives to solder pumps for wicking away unwanted solder.
• Applying flux helps the solder wick make good contact and absorb molten solder.
• Elevating components lets molten solder drip out when heating joints.
• Removing larger pieces requires carefully reheating all pins and gently shaking loose.
• Avoid overheating and damaging PCBs, components or joints in the process.
• Proper fume extraction is essential when extensively desoldering.
• While tedious, desoldering without a pump is feasible for removing small discrete components.

Solder Wick

Solder wick, also called desoldering braid, offers the simplest solder removal method without a pump. It consists of finely braided copper mesh with flux embedded into the strands. Pressing the wick against a heated solder joint causes the molten solder to be drawn into the mesh through capillary action.

To use solder wick:

• Cut off a piece slightly longer than the solder joint.
• Position it over the joint, pressing down with tweezers.
• Heat the joint with the iron until the solder melts into the wick.
• Remove the wick once the joint is desoldered.

The main advantages of solder wick are its low cost and simplicity. However, removing large amounts of solder across multiple joints can burn through many inches of wick quickly. Also, the wick does not remove solder as efficiently or completely as a suction pump.

Using Flux

For best results, apply a small amount of liquid flux to the solder wick before pressing it against the heated joint. The flux aids the wick’s wetting action, improving contact and allowing it to draw more solder away from the joint.

Be sure to clean any remaining flux residue from the board after desoldering using isopropyl alcohol to prevent corrosion. And use flux designed specifically for electronics rather than plumbing flux, which can contain acids harmful to electronics.

Elevating Components

Another basic technique is to raise up the component to be desoldered before heating joints. This allows molten solder to drip out of through-hole joints, or flow down away from surface-mount pads.

Methods to elevate components include:

• Pressing from the top with a thin tool or tweezer tip.
• Placing a small acrylic block underneath.
• Supporting bottom pins and leads on a silicon sticky mat.

As the joints reflow, gently shake or rock the component to encourage solder to drizzle out. Be careful not to apply so much force that the component or PCB pads get damaged.

Desoldering and Removing Larger Components

For larger multi-pin components like integrated circuits or connectors, simultaneously heating all terminals is key for fully desoldering and removal.

Carefully reheat each pin on both sides of the component. Apply solder wick or flux and allow the joints to fully liquefy before attempting to lift the component free. Check that all pins move freely by gently rocking or wiggling the component.

Once fully desoldered, very slowly lift the component perpendicular to the board to avoid ripping pads off. If needed, use a pair of tweezers to grasp and pull pins one side at a time.

Patience and repeatedly reapplying the iron is critical to evenly heating all the hidden inner surfaces. Rushing can overheat the PCB or component.

Avoiding Damage

It’s important to be cautious when desoldering not to damage boards or parts in the process:

• Don’t rapidly heat/cool solder joints to minimize thermal shock to components.
• Do not apply force on component leads until all solder is molten to avoid ripping pads off boards.
• Avoid prolonged heating that degrades the flux or chars the PCB substrate.
• Prevent static discharge which can destroy sensitive IC components.
• Check for lifted pads or fractured solder pads that weaken the joint.
• Ensure no solder shards or pieces of wick/braid are left behind shorting pads.

Careful desoldering technique minimizes the risks of collateral damage. But without a vacuum pump, more repetitive heating cycles are needed.

Proper Fume Extraction

When desoldering extensively, proper fume extraction is absolutely essential. Desoldering produces toxic lead and chemical fumes that must be captured and filtered.

Use a close-mounted fume extractor placed near the solder joint, and position it to avoid blowing fumes towards your face. Open windows or room fans are not sufficient – a filtered fume extractor is required for any significant desoldering work.

When Solder Pumps Are Better

While certainly feasible for removing small discrete components, desoldering ICs and larger connectors can be extremely tedious without a dedicated solder pump tool. The pumping action provides powerful vacuum suction that quickly clears joints in 1-2 pumps.

If doing production-level board rework and component removal, investing in a solder pump tool saves huge amounts of time and frustration. But for occasional desoldering needs, the manual wick and heating techniques can get the job done.

Conclusion

With some flux, finesse and patience, it is possible to desolder and remove components from a PCB without using a solder pump. For small-scale hobbyist projects, basic solder wick and manual heating methods can work. But for production desoldering jobs, a quality solder sucker makes the process far quicker and easier.

The most important factors are using ample flux, carefully controlling heat input, and gently removing parts only once all solder is fully melted. Avoiding damage to boards or components requires a delicate heating touch. And be sure to extract all solder fumes to protect your health.

While a specialized desoldering station is ideal, the manual techniques covered here can certainly get you through basic desoldering tasks in a pinch when you find yourself without your trusty solder pump tool. Just be slow, gentle and thorough when heating to avoid making a recoverable situation worse.

FAQ

Q: What can I use instead of solder wick if I don’t have any available?

A: In a pinch, regular braided wire can work similarly to wick soaked in flux. Some use stainless steel pot scrubbers too. But proper desoldering wick works most effectively.

Q: How do I remove solder from a wire joint without damaging the wire?

A: Use alligator clips on the wires as heat sinks. Keep the soldering iron moving continuously to avoid overheating the wire insulation.

Q: What temperature should I set the soldering iron to for desoldering?

A: Around 700-750°F offers a good balance for melting solder quickly without excessive heat. Higher temperatures can be used briefly if needed.

Q: How can I prevent pads from getting ripped off when removing components?

A: Always ensure all solder is fully melted before attempting to lift components. Rock side to side slowly to break all solder bonds before vertically lifting.

Q: I need to replace a processor chip. How do I fully desolder all the pins and legs?

A: Continuously reheat all pins while wicking each side. Chip should lift easily when all solder is melted. Do not force lifting before completely melted.

Q: What size tip should I use on the soldering iron for desoldering?

A: A pointed conical tip 1-2mm wide lets you focus heat precisely on a joint. A wide screwdriver-type tip works better for larger joints.

Q: Is it safe to breathe the fumes produced when desoldering a lot?

A: No – always use a fume extractor. Desoldering produces lead oxide fumes and flux vapors that should never be inhaled.

Q: After desoldering, there is still some solder left on the board pads. How do I completely clean it?

A: Reapply flux and solder wick to wick up remaining solder. Use solder braid to gently scrape pads. And clean with isopropyl alcohol.