Vertical Up vs Down Questions

[leeave96]

When vertical Mig welding 3/16" thick plate into 'T' or 'L' shapes, should the joints be welded vertical up or down & why?

Would the same technique apply for both Mig and stick?

Thanks!
Bill

[PAddy]

Vertical up will provide better penetration with the GMAW process.

[HAWK]

leeave96,

Good questions!

Vertical up also provides increased penetration with the SMAW (stick) process too! Everything structural welded in a vertical position should be upward travel.

Vertical down travel in both process provides for faster travel and less burn through.

There are some exceptions for pipe welding where both downhill and up hill passes are used in combination or perhaps downhill only.

[timw]

As posted vertical up has more strength. The trick to vertical up is you have to have your heat set right, not too hot, not too cold. Also you basicly weave pass going fast past the center and slowing on the sides to keep the puddle from dropping. You are stacking each weld on the previous pass. Once you get the hang of it and understand how it works it's not that bad. Vertical down is easy, looks great but turns out with little penatration or strength.

[Paul Seaman]

Vertical down is easier and in the learning process looks better to begin with. In agreement though vert. up is better once you get it, and then looks are mute point!