Handy Hints:
FIXING PROBLEMS RELATED TO WELD POROSITY
Common cause of weld porosity and solution you can use to limit porosity in your welds.
Cause: Impurities on the surface of your metal.
Solution: Clean your metal thoroughly before you weld it. You need to make sure it’s free of impurities like water, oil, and flux. If you’re welding aluminum, you have to make sure you clean off the outside layer of oxide before welding, or it will cause serious porosity.