4G MMAW
Posted: Thu Feb 04, 2010 8:34 pm
Hi guys,
I'm an Aussie Boilermaker in heavy construction. I mainly do iron ore plants,coal plants and the occational gas power station. As a boilermaker I actually don't do a lot of welding these days as it is mostly prefab and brought to site. However I'm being called upon to do more and more 4G. Now to my challenge.
I seem to always have trouble with the weld not getting enough penetration ie. not gathering the top edges. The weld tends to sag or I just can't get the penetration. We can't use a backing strip in most cases. I've tried using a knife edge V butt joint with and without gap, with landings with gap. with various amperage settings.
I've watched various videos but they do not show joint preparation. I try to keep the stick at 90 degrees with a tight arc. Over here we use 2.6mm 7016 for root runs and then 3.2mm 7018's for hot passes and capping.
What are your thoughts??
Cheers Horse
I'm an Aussie Boilermaker in heavy construction. I mainly do iron ore plants,coal plants and the occational gas power station. As a boilermaker I actually don't do a lot of welding these days as it is mostly prefab and brought to site. However I'm being called upon to do more and more 4G. Now to my challenge.
I seem to always have trouble with the weld not getting enough penetration ie. not gathering the top edges. The weld tends to sag or I just can't get the penetration. We can't use a backing strip in most cases. I've tried using a knife edge V butt joint with and without gap, with landings with gap. with various amperage settings.
I've watched various videos but they do not show joint preparation. I try to keep the stick at 90 degrees with a tight arc. Over here we use 2.6mm 7016 for root runs and then 3.2mm 7018's for hot passes and capping.
What are your thoughts??
Cheers Horse