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Help with open root mig

I have a weld test at a vessel fab shop that's going to be open root hardwire mig .035 wire on 1" plate with bevel. I've never done open root with mig. Can anyone help me as to what estimated settings and gap size would be best? They said it has to have "GOOD" penetration. Any position but what would also be the best position?

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It depends a lot on the angle of the bevel and the gap

for a 37.5 degree bevel on each plate, 19 volts and 230 inches per minute of wire speed will do it with a .125" gap and small land. ( .063"
)



if the bevel is narrower like 22.5 degrees, a full .125" gap is needed to get it done.
same settings will do with a tad more ipm.

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May 29, 2015
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by: Anonymous

I
Jan 15, 2015
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starstarstarstarstar 		welding roots NEW
by: Anonymous

if plate is 3/8 thick put 1/8 landing,3/16 gap set machine on 19 volts 135 amps ive welded roots at cameron valve for five years this is the spec we use.good luck god speed.




Jan 15, 2015
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starstarstarstarstar 		welding roots NEW
by: Anonymous

if plate is 3/8 thick put 1/8 landing,3/16 gap set machine on 19 volts 135 amps ive welded roots at cameron valve for five years this is the spec we use.good luck god speed.




Jul 02, 2012
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starstarstarstarstar 		MIG Welding Tips NEW
by: Anonymous

Fit-up: gap should be relatively large...I personally use 5/32". If this is you first go at it, I would recommend beveling to a knife edge. In reality, the land can be fairly large, but it takes a little more refined technique.

Procedure: do the root downhill using RMD mode. Every other pass should be uphill on Pro Pulse mode (or similar).

Technique: assuming the knife edge bevel, move side to side in crescent shapes down the root. If the coupon starts to keyhole increase oscillation speed and width (i.e. go further up the side of the bevel on both sides) until it starts to flow again. Do not worry about what it will look like. Root profile is hard to change with the MIG meaning that if it does keyhole, and you maintain your cool and keep going, you probably won't even be able to tell where the keyhole occurred. For the fills and cap, the easiest way is a 1-2-3 count on each side of the bevel using a staggered step pattern.

Settings: this varies from machine to machine. Ask the guys in the shop for advice.

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