To weave or not to weave?

[Llama]

Hi all,

I've been mig welding for a bit now, and when I was learning, I practised on small stuff, fillets and laps on <3mm steel. As I had seen in some of the videos, I would weave as much as I could. Little o's and e's on everything but a butt weld.

Then I worked in a fab shop for a while and was doing fillets on 35mm plate with a rather large three phase machine and spray transfer. The welds where somewhat cosmetic, and one of the guys told me not to weave, just build up a puddle then move it straight along

Is that due to the transfer type? Is weaving just a helpful technique for controlling speed? Or does it get used for other reasons.

I made myself a towbar the other day, I was quite happy with how the welds turned out. I looked back afterwards and realised that I didnt weave, just did what I had been with the industrial work on my smaller MIG at home.

Welder was a BOC 180P with pure CO2.

This is 16mm tongue onto 3mm

3mm onto 6mm plate with about a 2mm gap (ignore the lumpy bit on the side, it was me running over tacks and I cleaned it up later)

Any comments appreciated.

 

[Lawnmowerboy]

I never weave on anything under about 5-8mm. No need for it. Wastes time gas and wire and can have a detrimental effect on penetration. first welds look fine and have sunken in well. 2nd ones look a bit on the cold side to me?

 

[bpcoryton]

a lot depends on posision of the weld,type of joint&joint prep,root/hot pass/cap&size of weld etc.
1st fillet dosent go to both edges fully and may be a little to hot and dirty parent metal,2nd fillet looks a little cold/wire feed to high?and the fillet on the right(vertical) is way to cold/dirty parant metal and could have porosity in last part if you 'nick it' with a grinder.
i hate bare/soild mig wire,dual shield all day long as you can 'wash out' all the crap with it!
just my 2p worth.