Help. How do you avoid undercut.

[Mysfyt]

What SA said plus I'll throw this in: take a little time and clean your surface that you are going to weld with a 4-1/2 grinder. If you don't have one, get one! It's a welders best friend.

 

[4570Man]

I have an air powered grinder that is my favorite, a air powered grinder with a wire wheel, a big 6" handheld electric grinder, and a couple of bench grinders with one wire wheel. I usually do grind off the rust before welding.

 

[Arc weld]

Ok, you've got an SRH or maybe a Goldstar SS industrial 3 phase DC machine so no problems there. I think the first thing you should do is get some proper practice pieces. You won't learn anything welding a bunch of different scrap like the inside of an angle iron or across the back corner of it. I not sure if you understand what undercut is and may be confusing it with too much build up from the weld not wetting out. Other than the last weld picture I don't see any undercut. :confused3: About 125/130 amps should be in the ballpark. You need 4 basic things right to make a decent weld: Distance (arc length), Angle (rod angle), Speed (travel ) and Heat (amperage). Get some proper practice plates at least 1/4" thick and 6" long and experiment doing the same welds with different settings. Trying to learn how to weld and improve problem areas would take a month of years welding a different type of joint every time you ran a bead. Start off doing pad welds trying to keep a consistent width and straight line. Soapstone lines would help for straight lines and getting a consistent width.

 

[cormier]

Try to place yourself in as comfortable position you can, sit on a chair if you have to. then try to keep a steady travel speed. Remember, 7018 once its started you can actually drag it on your work piece, it doesn't need to have a gap between the end of the rod and work piece. For beginners keep your arc length as close to you work as you can, once you get the hang of it you can start giving a little arc length and experiment till you find what works best for you. To long of arc length will give you undercut for sure. Don't look at the rod when your welding, look at the puddle behind the rod and learn how to read it. A nice even consistent puddle = nice weld

 

[CNC Dan]

I find that I listen to the sound of the arc to tell me what the arc length is.

Try listening to the sound as you go from long to short arc length. That might free up your eyes to look at the puddle.

Also check out the videos from wall mountain.

 

[Shield Arc]

I find that I listen to the sound of the arc to tell me what the arc length is.

Try listening to the sound as you go from long to short arc length. That might free up your eyes to look at the puddle.

Sound of the arc tells me a lot. Changes in the sound will get my attention fast. When I'm welding I kind of day dream, I'm generally thinking of the next 4 or 5 moves I have to make.
It's like driving a car, when driving do you think about driving, or a thousand other things?:laughing: