You control slag deposition in 3 ways…travel speed, arc length, and angle of electrode. Experiment with all 3.

Higher amp for T-joints then for flat (2 surfaces)

Work on clean metal. It's not a deep penetration rod and therefore does not burn though surface contaminants very well.

In T-joint hold rot 30-35 degrees from horizontal plane, to make sure that enough is deposit on the vertical plane. Gravity will take care of horizontal plane

Having a slag stringer in the start of a 6013 bead is very common. What you are seeing is the heavy flux on top of the weld pool, and not molten metal. Getting a slightly slower start to the weld bead will solve this problem. A little hesitation before moving the rod will give the puddle time to bridge between both surfaces and solve this problem.

Try pausing when you first strike up so that a puddle can form and slow the travel speed down a little for the first inch

holding too long of an arc length, and it is difficult to manipulate the metal where to go. Put the rod right into the crack

1.6 rods are difficult to learn. 2mm aren't much better. 2.5 are the best place to start, you can get away with a lot, but picking up bad habits isn't easy, with 3.2mm rods you can just drag the end of the rod on the metal and it will weld, try that with a 2.5 and you will find problems. 1.6mm rods burn away faster than a sneeze and are hard to control.

6010

7018 (7016)