these welds were done with 2.4mm rods and where they didnt peel i used a wire brush and pushed the slag of, the only reason i think they look poor is because i did it on the floor out of practise and didnt go in a striaght line ahah
I find they tend to peel if the metal is really cold (as said above), and you start moving straight away as soon as the arc is struck. And yes, that's with Aldi rods.
Most of mine come off in one piece with a prod from a screwdriver near the start though, so I guess the slag is more stuck down at the start of the weld, but sufficiently detached from the weld to just fall off once that bond is broken.
I still need to work on getting my verticals to detach the slag as easily though - they generally take a bit of chipping or wire brushing to remove.