[steelbeam78]

My son and I are practicing running stringer beads with 7018 vertical.
Machine is set at about 100 amps. We are using 1/8" rod.
Having trouble with the weld sagging. We are keeping a pretty tight arc.
Any suggestions?

[Otto Nobedder]

Assuming your amp indicator is right (and that is a huge assumption on a machine that's not been calibrated since it was new, if then), you're running a little cold. It took me very much practice to do that at 105A so I could do all positions on pipe at the same setting I could run a "bury-rod" 1/8" 6010 root.

Typically, a vertical "up" with 1/8" 7018 is done anywhere from 110 to 125A. Some can do it even hotter, and some, like me, can do it colder, but if you're beginning, I'd start at 115A. Hold on each side, sweep fast across the middle, and don't get in a hurry to get to the top. Patience is the secret to all things.

Steve S

[Mike]

Welcome to the forum.

[Mike]

Welcome to the forum.

[Boomer63]

Laying a stringer on a bare plate with 7018 1/8" is not easy. The weld seems to want to pile up and look like a fat worm laying on the iron.

Try taking your grinder and making some 'U' grooves about 1/4" apart. After you run those stringers, you can fill in the new valleys you have created.

Also, for starters, try your plate at something more like a 45 degree angle, rather than heading straight for the 90. Then when you get comfortable with the 45, work the transition to the 90!
Gary

[weldingt]

Try a very slight manipulation side to side with a distinct pause in each side. The bead does not have to be very wide for this to affect the sagging through the middle. Another option is to start with a smaller electrode.

Also note this, if you are welding an material that is in the thinner side, heat in the base metal can be a cause of the convexity.

[Owr]

As the previous poster mentioned, base metal thickness can be a factor too when you have weld sagging.

For 1/8 vertical stringer you could go below 100 amps, the lower the better since travel speed will be slow. When you strike the arc and get a good "burn" of the rod, get a really tight arc length so the voltage drops. You can then manipulate rod angle for a little extra help against weld sagging.

Imagine a rod is a wax candle that you drag on a hot surface - lay it on the surface and let it melt with a slow, low force arc so the stringer builds up itself if that makes any sense. Rutile coated stainless rods on ss is best practice for this, makes mild steel runs seem "easy":).

[Nome27]

What brand of E7018 are you using? I find i run a lot hotter with lincoln excaliburs than i do with say hobart 7018. When i run vertical up i tend to run a little hotter and hold a slightly longer arc length (not long arc length just a little longer than i would running flat position) this might help to spread the bead out because a longer arc length decreases amps and increases volts giving the arc itself a little more power to jump the gap and spread the bead (holding a tighter arc increases amps and decreases volts because the arc doesnt have as far of a gap to jump from the rod tip to base mettal). In combination with that add a small wiggle from side to side as you move at a steady pace up the joint. Rod angle is also very important, i ty to aim straight in, neither up nor down, straight in, aiming up will push heat up the joint as you travel and by the time you get to the top it may become hard to control the puddle especialy on thinner base metal, And play with your amperage, i know some guys that weld real hot and others that weld cold so finding amperage your comfortable with is important.