So I have my new arc welder and am trying to relearn. I have four different sorts of 2.5mm 6013 rods to work with, some unbranded that came with the welder, some "Magma Weld", some Oerlikon Overcord, and some SIP that I found in the cupboard left over. Of the four types I am finding the SIP impossible, the arc strikes erratically, and once running it's prone to sticking and welding itself solid to the work. None of the others do that, in fact I can't remember ever having a rod stick while running. So my question, are SIP really that bad, or should I persist with them? They're old, maybe 20 years but my workshop is pretty dry. Is it work sticking them in the airing cupboard for a few months? I hate to scrap anything, and I also found some SIP 2.0mm which I would really like to try as well - I may have some jobs where 2.5 is a bit big.