Proper storage and controlled transportation are crucial for the quality of welding rods.
If the humidity is too high - e.g. over 60% or if temperatures fluctuate greatly - oxidation of the wire surface can occur. This oxide layer impairs the metallurgical bonding process during welding.
A common phenomenon resulting from such oxidation are so-called silicon islands: residues of Si-containing alloy components that do not integrate correctly into the weld seam and remain as visible, dark spots on the surface.