What's the most common welding defect

In my experience as a welding inspector, the most prevalent defect I encounter is porosity. It’s a tricky issue, often caused by contaminants in the base material or improper shielding. Have you all noticed similar trends, or do you see other defects more frequently in your work?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌⁠‌⁠‌‍‍‍​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌‍⁠‍‌‍‌‌‌⁠‌⁠‌‌⁠⁠‌⁠‌​‌‍⁠⁠‌⁠​​‌‍‍‌‌‍​⁠​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​‍​‍‌‍⁠‍‌‍‌‌‌⁠‌⁠​‍​‍​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠​‍​⁠​‍​⁠‌​​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌‌​‍‌​⁠‌‌⁠‍‌​⁠‌⁠‌​‌​‌​‍‍​⁠​⁠‌‍⁠‌‌⁠‌​‌‍‌‍​⁠‌⁠‌⁠‍​​⁠​‌‌‍‌⁠‌⁠‌⁠‌‍‌​​‍​‍‌⁠⁠‌​​

Porosity really is like that stubborn stain on your favorite shirt — it just won’t go away! I’ve seen lack of preheat be a common culprit too. Have you ever tried adjusting your settings to see if it helps?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌⁠‌⁠‌‍‍‍​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠‌‌​⁠‌​​⁠‌⁠​⁠​​​⁠‍‌​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠​‍​⁠​‍​⁠‌⁠​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌‍‌‍‌‌​‌‌​‌​​⁠​‍​⁠‌⁠‌​‌​‌‌‍​‌⁠‍‍‌‌‌​‌​⁠‌‌‍‌​‌​‍​‌⁠‍​‌⁠​‌‌‍‍⁠‌​⁠​​‍​‍‌⁠⁠‌

I’ve noticed porosity too, especially with contaminants. Have you tried using different shielding gases? What works best for you?

‌⁠‍⁠​‍​‍‌⁠‌​​‍​‍​⁠‍‍​‍​‍‌‍‌⁠‌⁠‌⁠‌‍‍‍​‍​‍​‍⁠​​‍​‍‌‍‍⁠​‍​‍​⁠‍‍​‍​‍‌⁠​‍‌‍‌‌‌⁠​​‌‍⁠​‌⁠‍‌​‍​‍​‍⁠​​‍​‍‌‍‍‌‌‍‌​​‍​‍​⁠‍‍​⁠‌‌​⁠‌​​⁠‌⁠​⁠​​​⁠‍‌​‍⁠​​‍​‍‌‍‌​​‍​‍​⁠‍‍​‍​‍​⁠​‍​⁠​​​⁠​‍​⁠‌‍​⁠​​​⁠​⁠​⁠​​​⁠‌‌​‍​‍​‍⁠​​‍​‍‌‍‍​​‍​‍​⁠‍‍​‍​‍‌⁠​⁠‌‌​⁠‌‍​⁠​⁠‌‍‌‍‍​‌​‍​‌⁠‌‍‌⁠​⁠‌​‍​‌​‌‌‌‍​⁠‌‍‌​‌⁠​‍‌‌‌‌‌​⁠⁠‌‍‍‍​‍​‍‌⁠⁠‌