Diagnose common solder-line problems
Use what the seam looks like to adjust heat, speed, cleanliness, and solder feed.
Practical referenceReviewed August 2026
Flat or starved seams
Add solder steadily and move at a controlled pace. Repeatedly reheating tiny amounts can leave an uneven, weak-looking line.
Peaks and ridges
The solder may be cooling before it flows. Check tip condition and temperature, then work in shorter deliberate sections.
Dull or contaminated joints
Clean and reflux the area. Oxidation, exhausted flux, residue, or a dirty tip can prevent a smooth bond.
Heat damage
Lifted foil, burned adhesive, and cracked glass signal too much concentrated heat. Alternate areas and let the panel cool instead of chasing one seam.