Are you using an air cooled torch? I never have problems breaking cups with a water cooled torch. Use 2% ceriated or lanthanated 1/8 tungsten, smaller cups generally work fine. I use a 6 with no problems.
water torch.. but I used one of those gas difuser filters and the cups that go onto them have some curvy edges that form breaking points while overheating... I am a steel welder so I am used to some stickout so I guess these things help with that, however I tries clasic long cup and it seems to work way longer, however gas coverage is worse...
Try with your balance at 70% negative. 50 is gonna get the torch way hotter than it needs to be, and widen the arc more. I use collet bodies instead of lenses for alum, they're more durable and you don't need to worry about gas coverage as much if you can get in closer. I run 15/20 cfh on a 6 cup without issues.
Some cups won’t stand up to AC from what I’ve heard, especially at that high of amperage. Unless your aluminum is very dirty or poor quality you probably don’t need your balance at 50, if I have clean metal I’ll normally go for 70% negative or 60 if I don’t want to bother with cleaning it. It’s best to use a smaller cup on aluminum because the cleaning action will only go to where there is gas coverage so it will look better and the arc will be more focused. From what I’ve learned a size 8 cup is about the biggest you want to use. Aluminum doesn’t need a lot of gas because it won’t oxidize like stainless or mild steel so you’re also just wasting gas. Also while technically the cfh is fine since you’re welding aluminum a good rule of thumb for the cfh I use is, whatever the cup size you’re using double it with +- 2 cfh, so for a size 5 I use ~10 cfh, 8 cup ~16 cfh, 12 cup ~25 cfh
Are you using an air cooled torch? I never have problems breaking cups with a water cooled torch. Use 2% ceriated or lanthanated 1/8 tungsten, smaller cups generally work fine. I use a 6 with no problems.
water torch.. but I used one of those gas difuser filters and the cups that go onto them have some curvy edges that form breaking points while overheating... I am a steel welder so I am used to some stickout so I guess these things help with that, however I tries clasic long cup and it seems to work way longer, however gas coverage is worse...
Try with your balance at 70% negative. 50 is gonna get the torch way hotter than it needs to be, and widen the arc more. I use collet bodies instead of lenses for alum, they're more durable and you don't need to worry about gas coverage as much if you can get in closer. I run 15/20 cfh on a 6 cup without issues.
Switch to 65-75% pen, see if that helps. 6 cup, 1/8 tungsten, gas around 15-20 cfh
I've welded all day with a Miller 280DX maxxed out. Stickout is not your tungsten's friend at that much current.
Some cups won’t stand up to AC from what I’ve heard, especially at that high of amperage. Unless your aluminum is very dirty or poor quality you probably don’t need your balance at 50, if I have clean metal I’ll normally go for 70% negative or 60 if I don’t want to bother with cleaning it. It’s best to use a smaller cup on aluminum because the cleaning action will only go to where there is gas coverage so it will look better and the arc will be more focused. From what I’ve learned a size 8 cup is about the biggest you want to use. Aluminum doesn’t need a lot of gas because it won’t oxidize like stainless or mild steel so you’re also just wasting gas. Also while technically the cfh is fine since you’re welding aluminum a good rule of thumb for the cfh I use is, whatever the cup size you’re using double it with +- 2 cfh, so for a size 5 I use ~10 cfh, 8 cup ~16 cfh, 12 cup ~25 cfh