Mig welding overhead Question
I need to do some mig welding overhead. The thickness of the material is 1 CM (.393") its 5 Cm ( 2") wide and 20 cm ( 8") long but i got my machine on this: 24 Volts 140 amps
Answer to mig welding Question
The best advice I can give you for welding overhead with Mig is pay attention to 3 things:
1. Make sure and have the machine set hot enough...I use the same settings I would use welding flat. 21 volts sounds pretty good but is probable too hot for an open butt root.
2. Make sure your stickout is right...Stickout being the distance between the arc and the copper contact tip. Make sure the contact tip is at least flush with the nozzle and preferably protruding about 1/16". Even if you have to trim the nozzle to get this it is well worth it..... and keep the stickout to 1/2"--3/8"...this is really important.
3. keep the torch angle to a minumum. Dead nuts straight in is good . if you are welding an open butt v groove weld, use about a 5 degree drag angle for the root...and a 5 degree push angle for the fill passes. Stay on the front of the puddle all the while keeping your stickout no more than 3/8"
The Two problems I see most often on overhead mig is too much stickout and too much torch angle..number three is not welding hot enough. Using a long stickout along with not enough amperage just makes the weld pile up high.
Using enough amperge, good stickout, and correct angle lets the arc force punch the weld and helps it flatten out.
The Rule of thumb Wire feed settings table below can help you in getting your machine set right. You will need to convert cm to inches but since you said you were welding with 140 amps, if you are using .035" wire, that would be 224 ipm. I think your voltage is pretty high. I would try lowering the voltage to around 20-21.
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