How to Desolder a Joint

The soldering iron is the main tool in both soldering and desoldering.

Simple devices such as capacitors, diodes, resistors, transistors and integrated circuits are electrically connected through soldering. Individually, these little parts would be useless. Electricians use soldering irons to connect these devices to each other, as well as to other mechanical devices, such as creating a connection between the unit and a circuit board. Of equal importance is the ability of the electrician to desolder, which is removing a solder from a joint. There are three ways of desoldering. One way requires the use of an agent. Another method requires the usage of vacuum pumps. You can also use a specialized tool called a desoldering iron.

Things You'll Need

• Soldering iron
• Desoldering braid
• Vacuum pumps (solder suckers)
• Desoldering iron

Instructions

Desoldering with Copper Braid

1. Remove any grease, glue or varnish on the joint before you start heating.

2. Position the iron tip against both the component lead and the board. Give it a second or two to heat up.

3. Place the tip of the copper braid against the cold solder.

4. Stick the soldering iron against the desoldering braid. This will heat up both the solder and the braid, but make sure that the copper gets most of the heat.

5. "Pick up" the solder once the copper has mixed with the melted solder, using the soldering iron. You can also pick out the solder with a pair of tongs after letting it cool a bit.

Desoldering with Solder Sucker

1. Remove any grease, glue or varnish from the joint before you start heating.

2. Heat the solder with a soldering iron or a soldering braid. This will soften up the material.

3. Push down on the plunger of a vacuum pump solder sucker, until you hear or feel a click. This means that the machine is ready for use. In the alternative, if you are using a ball-pump solder sucker, squeeze the ball in preparation.

4. Remove the soldering iron from the molten solder, and place the sucker in its place.

5. Push the button of the pump solder sucker. This will create a vacuum that will suck out the old solder. If you are using a ball-pump solder sucker, releasing your hold on the ball pump will achieve the same effect.

Desoldering with Desoldering Iron

1. Remove any grease, glue or varnish from the joint before you start heating.

2. Place a bit of tin on the tip of the desoldering iron, in the same way you would on a normal soldering iron.

3. Push the pump/press on the ball of the vacuum component of the desoldering iron in preparation.

4. Place the iron tip against the solder joint in order to melt the material.

5. Push the button of the pump solder sucker or release the ball of the ball-pump solder sucker once the solder has melted enough. This will create a vacuum that will pull out the old solder.

Tips & Warnings

• Be careful while you are desoldering; the resin in the solder, and the coating on the board, can both release toxic fumes. It's best to work in a well-ventilated area.

• Remember that a hot solder is hazardous. Molten material can hurt or maim you. Wear protective headgear and gloves in order to keep your head and arms safe.

References

• New Mexico State University, College of Engineering; Soldering; Mark J. Hoban and Barry M. Lunt; 1997
• Electronics Projects: How to Desolder
• West Florida Components: Desoldering - Why Is It Necessary and How Is It Done? October 2008

Resources

• Aaron's Homepage; Electronics - How to Desolder; Aaron Cake