Aluminum gel frames
Posted: Mon Nov 12, 2018 2:05 pm
I'm welding 48" x 48" 6061 aluminum film lighting gel frames from 1/4" x 1" bar. I'm welding with a Lincoln PT185, with a WP-26 torch, 3/32" thoriated tungsten, and 3/32" 4043 aluminum rod. My joints are all butt welds with the bar cut at a 45 degree miter and each miter beveled to a clean edge.
Because I've had trouble with the material literally dropping away, I'm backing each joint with a 18" x 18" x 5/8" piece of solid aluminum. This helps greatly to pull the heat out of the joint. It also obviously means I have to crank up the amperage to get a good weld.
When I get a chance, I'll post a picture of my welds. In the meantime, I'm concerned that I'm not getting full penetration on my "root" pass (I'm not actually doing more than one pass on this relatively thin material). When I weld the first side (all four corners) and then flip the piece over, I have not actually welded through. In other words, that knife edge where the two pieces meet to be welded is still a knife edge.
Should I be concerned about this? Please understand that this is not a critical application and these joints are not under tremendous stress. But still, in addition to my wanting my welds to look good, I also don't want them to break and come back to me for repair.
Any advice would be appreciated. Who knows? Maybe someone out there thinks I should be doing multiple passes, starting with a DC- pass and then switching to AC. I'm always open to suggestions.
THKS!
Jon
Because I've had trouble with the material literally dropping away, I'm backing each joint with a 18" x 18" x 5/8" piece of solid aluminum. This helps greatly to pull the heat out of the joint. It also obviously means I have to crank up the amperage to get a good weld.
When I get a chance, I'll post a picture of my welds. In the meantime, I'm concerned that I'm not getting full penetration on my "root" pass (I'm not actually doing more than one pass on this relatively thin material). When I weld the first side (all four corners) and then flip the piece over, I have not actually welded through. In other words, that knife edge where the two pieces meet to be welded is still a knife edge.
Should I be concerned about this? Please understand that this is not a critical application and these joints are not under tremendous stress. But still, in addition to my wanting my welds to look good, I also don't want them to break and come back to me for repair.
Any advice would be appreciated. Who knows? Maybe someone out there thinks I should be doing multiple passes, starting with a DC- pass and then switching to AC. I'm always open to suggestions.
THKS!
Jon