pipe welding with lo/hi

[1423 stuart]

hi every one need some advice on welding carbon steel pipe with lo hydregon pipe rods ,ive been told conflicting advice on revercing the polarity from a negative earth to a positive earth when using them ,hope someone can answer this ....many thanks...stu..

 

[Paul.]

Hi Welcome to the forum
Electrode polarity will depend on what you are actually using, Low hydrogens are not all the same, the info on the electrode packet should give you the answer, or a WPS (if you're working to one). Although most that Ive come across are DC electrode +, and some can be used either way
If you can Identify the make and AWS number, post it here and I'm sure one of us will look it up for you.

 

[TechnicAl]

usually Negative Root , Positive Fill and Cap

 

[DIY Welding]

Depends on which electrode, what size and shed pipe and what equipment you are using ie ac or dc output some low hy rods actually run better on ac

 

[aero]

If you have a large fillet to fill AC is better due - I believe - to the constantly reversing magnetic field. I have only ever used them on AC, but thats the only set I have.