MIG welding over tacks

[GrahamGKD]

I'm MIG welding some ordinary steel box section together (T joints) which involves tacking it, checking angles etc. and then welding the four sides. On heavier projects when I have been MMA welding I normally find I can 'melt' over the tack with the permanent weld and end up with a result which doesn’t show where the tack was. With this MIG job, though, I'm finding I need to tack two sides, weld the other two sides and then grind off the tack before welding the last two sides (where the tacks were) to get a nice looking finished weld over the tack.

I was just wondering what you folks out there normally do please? Is there a trick to welding over a tack without grinding it off first?

Cheers,

Graham.

 

[Hitch]

Tack it right on the corners, then a slight lump doesnt notice as it would if you tacked it elsewhere.

 

[GrahamGKD]

Tack it right on the corners, then a slight lump doesnt notice as it would if you tacked it elsewhere.

Ah yes - why didn't I think of that!! Thanks, Graham.

 

[weldingscotty803]

Tack it right on the corners, then a slight lump doesnt notice as it would if you tacked it elsewhere.

same here
atb scott

 

[Weldingartisan]

Wind the juice up for the tacks to give a flat profile. W/A

 

[3Rs]

What I do is feather edge the ends with a grinder then weld into the teck,

What you have to remember is that a teck is a weld in it self.

 

[Welderpaul]

Tack it right on the corners, then a slight lump doesnt notice as it would if you tacked it elsewhere.

Its easier to align the joint if its tacked on the corners