Guide
Soldering Tips: Common Mistakes and How to Fix Them
Published:
TL;DR
- A dirty, oxidised tip is the most common cause of poor soldering, and the most overlooked fix.
- Tin the tip at the start of every session, not just when it looks obviously dirty.
- Solder that balls up instead of flowing is almost always a flux problem, not a heat problem.
- A tip that won't heat components properly even at high temperature may need replacing, tips wear out.
Solder won't stick to the joint
This is usually oxidation, either on the tip or the surface being soldered, not lacking heat. Wipe the tip clean, re-tin it, and try adding a little extra flux to the joint before soldering again. Our full breakdown of this specific problem is in the FAQ.
Joints look dull or grainy instead of shiny
A dull, grainy joint (a cold joint) means it wasn't hot enough when the solder was applied, or it moved before cooling. Reheat the joint fully until the solder flows again, then hold everything still while it cools.
Solder balls up on the tip instead of flowing onto the joint
This points to a flux problem: either the tip is too oxidised for the solder to wet it, or the joint surface itself is oxidised. Clean the tip, re-tin it, and add extra flux to stubborn joints rather than just adding more heat.
The tip stops heating components properly
Iron tips wear out. A tip that's pitted, black, or won't tin no matter how much you clean it has likely reached the end of its life and needs replacing, this is normal wear, not a fault with the iron itself.
Keep the tip clean between joints
Wipe the hot tip on a damp sponge or brass wool between joints to remove built-up oxidised solder, then re-tin it before the next joint. A tip cleaned this way through a session lasts longer and solders more consistently than one left to build up residue.