Question 1

What does 'low hydrogen' mean and why does it matter?

Accepted Answer

Low-hydrogen electrodes (E7018, E7016) have moisture-resistant coatings that produce less than 4 mL of diffusible hydrogen per 100g of weld metal. Hydrogen causes cold cracking in medium/high carbon steels and is the #1 cause of weld failure in structural applications. These rods must be stored in heated ovens (120-150°C) after opening and used within 4 hours of exposure.

Question 2

Can I use the same rod for all positions?

Accepted Answer

Not all electrodes work in every position. The third digit in the AWS classification indicates position capability: '1' = all positions (flat, horizontal, vertical, overhead), '2' = flat and horizontal only. E7018 is all-position, but E7024 (high iron powder for high deposition) is limited to flat and horizontal. For vertical-up and overhead work, use '1'-designated electrodes with appropriate technique.