it's probably me

[Turbo]

You made a bad choice of metal and rods to practice your arc welding - that combination would be difficult for even an experienced welder! On metal that light you should've used your mig.
If you want to practice arc start with good quality 3.2 rods and at least 4mm thick metal. As you improve step up to 2.4 rods & lighter metal. Since you have a mig don't bother with the 1.6 or 2mm rods. Given their age they are probably junk anyway.

 

[rich the mechanic]

Just a thought as i don't remember seeing it with arc can you make several passes over a short distance say a couple of inches or is it once you pass a point the slag needs to be removed before going over again?

 

[Bill Edwards]

You need to remove all the slag before you can weld again. A wire brush is very helpful for this if there are bits that won't fall off.

 

[rich the mechanic]

I had been chipping and brushing didn't know if you got a second hit while it was still hot or not.

 

[Bill Edwards]

Once the weld has solidified (which doesn't take long) the slag has to be removed before you can weld again, otherwise it will make a big mess of the next weld.