Why it is sometimes necessary to preheat the base material before welding?
a) To remove oil and grease
b) To remove moisture from inside the material
c) To prevent the possible risk of cracking
d) Not required if using cellulosic electrodes as these will provide enough heat
a) To remove oil and grease
b) To remove moisture from inside the material
c) To prevent the possible risk of cracking
d) Not required if using cellulosic electrodes as these will provide enough heat