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7018 3G with Backing strip

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7018 3G with Backing strip

Postby zachpalm96 » Sun Feb 11, 2018 5:58 pm

Currently enrolled in trade school to get my welding cert. I am in my 2nd semester and I am having a hard time dealing with the 3G position. I have always struggled with vertical welding. My root pass always comes out great and exactly how I need it to be for me to run my next pass. However, when I run my 2nd pass, I have a huge amount of undercut, my bead isn't straight, and there is build up in certain areas. I can see my puddle just fine, but I am pretty sure my travel speed and angle is off. Any tips on how to fill up a v-groove and cap it in a 3g position?
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Re: 7018 3G with Backing strip

Postby MinnesotaDave » Tue Feb 13, 2018 8:04 am

Here's part 2 of the series Jody did
Dave J.

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Re: 7018 3G with Backing strip

Postby Farmwelding » Tue Feb 13, 2018 11:37 am

My biggest struggle with 3g was the cap pass. I figured out to not touch it until the area of the weld joint wasn't over 250 degrees. I used an infrared thermometer. I played with temperatures and thats what worked best. Just give them toes some love if you are getting undercut. Stringers or weave?
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Re: 7018 3G with Backing strip

Postby PeteM » Wed Feb 14, 2018 1:16 am

A pic of each pass where the problem is occuring would help, minus that, what I've seen a lot of people do is not stick the sides adequately or in the right place, and end up with a ropy log looking thing in the middle.
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7018 3G with Backing strip

Postby snoeproe » Wed Feb 14, 2018 1:27 pm

You have to use a side to side oscillation when welding vertical up. Even your stringers must be ran with a slight side to side z motion. You need to pause briefly on each side of your side to side motion. It's just a very small weave technique. If you dwell in the middle or just try running straight up, you get a vine full of grapes and valleys with undercut on the toes.
The pausing on the sides helps fill the undercut and valleys and flatten the bead. Don't dwell in the middle with your rod, the middle takes care of itself.
If you amps are set too high, you will notice it starting to dig on you about 3/4 of the way up the plate.
I always weave my cap and last fill passes on vertical up. I find I can control my cap height, undercut and cap appearance better when I weave. Vertical is the only position that I weave in.
I like to have my plate as hot as possible when welding with stick. That heat can help you with fusion and cap appearance, as long as you learn to control everything with it.
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Re: 7018 3G with Backing strip

Postby Poland308 » Wed Feb 14, 2018 9:07 pm

My motion is more of a c but it’s open side is up and favors one side more than the other.
I have more questions than answers

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