From using desoldering irons to sketchily knocking breadboard components off on the side of a table, there are tons of ways to remove components from a circuit board. Desoldering is an important skill to learn once you've gotten the hang of soldering, because messing up a soldering job isn't improbable.
The basic concept of desoldering is very simple: you need to heat up the solder, then you need to figure out how to get the component or wires out nicely, and then you need to clean up all the solder still attached to the board and/or the component. In this guide you'll learn many of the diverse methods used to desolder through-hole components, from the nice, clean techniques to the last resort, end of the world schemes to get your desperately needed components back. If you have any other desoldering methods, please comment!
Step 1: How to Use a Soldering Iron to Desolder
If all you have is a soldering iron, then your only option is to heat up the solder and fiddle with it until you can get the components out. Here's what you can do:
1. Heat up the solder with the iron.
2. Slide the iron up the pins to bring the majority of the solder away from the joint.
2. Using pliers, gently pull at the components to remove their pins from the pin holes while they are still hot. It's a good idea to pull by their leads as opposed to on the components themselves to maintain the quality of the component.
Tip (edit): If you need to get excess solder out of holes, try sticking something like a safety pin or needle through to clear out the through-holes. Using the tip of the soldering iron will remove the copper plating from the PCB.
Pros: You need nothing but a soldering iron, and the components can be reused.
Cons: You may damage the board if you leave the soldering iron on it for too long.
Step 2: How to Use Desoldering Braid
Desoldering braid, or solder wick, is a nice desoldering method used to essentially soak up unwanted solder. It comes in a coil of braided together strands of wire. Because copper conducts heat well, and solder is attracted to heat, by heating up the braid you can draw the solder off your part and into the braid. Some desolering braid comes with flux within it, which makes it much easier and cleaner to remove a part. If your soldering braid does not contain flux, then you can apply it by dipping the section of the braid you will use into the flux. Here's how to use it:
1. Unwind a few inches of braid from the coil.
2. If your solder wick does not have flux on it, it would be a good idea to add flux to the section you are going to use to make for a clean removal.
3. Place the braid over the joint you want to rework.
4. Place a hot soldering iron against the braid and desired pin.
5. Wait a few seconds. The solder will flow off the pin and onto the braid.
6. Remove the braid. The braid will be very hot at this point, so make sure not to touch the braid itself, only the spool.
7. Remove the component.
8. Repeat steps 1-5 to remove excess solder.
Tip: Use a pair of needle-nose pliers to position and hold down the braid without getting burned.
Pros: It's cheap and easy to use, and comes in various sizes depending on the magnitude of the solder you want to remove. Desoldering braid is great for removing solder from flat surfaces. Removed components can be reused.
Cons: Desoldering braid isn't reusable, you'll want to start with a clean segment of braid each time you use it. Because it gets so hot, it can be tough to reposition once you've started. It's also pretty hard to get solder out of pin holes.
Step 3: How to Use a Desoldering Pump
One of the nicest ways to desolder a component involves using a desoldering pump. A desoldering pump is essentially a small, high pressure vacuum. After heating up the solder, you can use the desoldering pump to suck the solder up and out of the way. Here are the basic steps for using a hand-powered desoldering pump:
1. Heat up the solder you want to remove with a soldering iron (some desoldering pumps also come with attached irons).
2. Press down on the plunger (If your pump has a bulb, just squeeze the bulb).
3. Once the solder is molten, place the tip of the desoldering pump against the solder that you want to remove.
4. Release the plunger or bulb. Some desoldering pumps have a release button so that you don't have to hold it the whole time.
5. Remove free component.
6. Repeat steps 1-4 to remove any excess solder.
7. Dispose of the solder inside the pump by repeatedly pressing down and releasing the plunger.
Tip: If you are trying to remove excess bits of solder, you may want to add more solder to the joint, because the solder will stay liquid for longer when in larger "blobs", and thus be easier to remove.
Pros: Desoldering pumps come in a wide range of styles, from handheld pumps to electronic, heated guns that require no iron to use. They are great for reworking small parts and getting solder out of pin holes. Removed components can be reused.
Cons: Although the pumps can have small tips, they are large in general and may be hard to get into very tight spaces.
Step 4: How to Use a Heat Gun to Desolder
Using a heat gun is another way to remove solder without the use of a soldering iron. Basically, it heats up the solder enough to be able to remove the components. Using a hot air station is a slightly more professional and expensive way of doing this, as it is basically a heat gun specifically meant for desoldering. If you don't have one of those though, here's how you can use a heat gun to desolder components:
1. Turn on the heat gun.
2. Use pliers to hold the circuit board above the air streaTim.
3. Use a pair of needle nose pliers to pull the component out of the board.
Tip: You only need to heat gun the board for a few seconds, or else you will melt the copper plating on the PCB and damage the board, as shown in the picture.
Pros: Simple and quick way to get a component out of a PCB without a soldering iron. The components may be reused, depending on the damage done.
Cons: It can get very, very hot. The board itself heats up pretty quickly, and you can damage it or your fingers pretty badly if you aren't careful. The components and/or the board may not be salvageable.
Step 5: How to Use Compressed Air to Desolder (Method 1)
If you don't have access to some of the tools I mentioned previously, there are a couple other neat ways to remove components if you desperately need them, and using a compressed air can is one of them. You can use it to remove solder from your component by simply blasting molten solder away. Here's how:
WARNING: If you are going to do this, you must wear safety glasses. This method sends chunks of molten solder flying everywhere.
1. Heat up the solder with a soldering iron.
2. Once the solder is molten, get the nose of the compressed air can or gun up close to the joint.
3. Blast it with air, with the nozzle pointing away from you.
Tip: Because the air can is pretty powerful, you can heat up solder stuck in pin holes and blast it out
Pros: It's fun, messy, quick, and who doesn't love playing with compressed air? Also, the removed components can be reused.
Cons: It's messy, so solder may get all over your workspace and circuit board if you aren't careful with your aim. This is why you need safety glasses.
Step 6: How to Use Compressed Air to Desolder (Method 2)
Don't have access to a soldering iron? That's ok! You can use a compressed air in another neat (but more aggressive) way to remove soldered components. When you turn a compressed air can upside-down, it sprays out a freezing cold liquid solvent. This super-cools the solder, making it extremely brittle. Here's what you can do:
1. Turn the compressed air car upside-down.
2. Spray it against the joints. Parts of the board (top and bottom) will turn while, but after a few seconds it will return to normal.
3. Wrench the components off with pliers.
Tip: If you don't have pliers, you can knock the components off using the edge of a table.
Pros: You don't need a soldering iron, and you get to see what happens when you turn an air can upside-down! This process is also the only one that isn't very hot.
Cons: Components cannot always be salvaged.
Step 7: Experiment and Explore!
Desoldering can be pretty tricky business, and many people have come up with their own techniques to cleanly removing their components from a circuit board. This instructable only covered how to remove through-hole components, but there are many other ways to desolder other types of circuits. If you have any other desoldering methods you'd like to share, please add them in the comments!