[Julesomega]

Re the grades of rosin flux, I'm not sure what I'm using, most likely RMA. It was being thrown out of Stores 25 years ago for exceeding the use by date, I can only read "Ersin Multicore Rosin Flux Type 5381 1L" so I have several lifetime's supply. We later used a pale blue water-based flux which left no residue and was slightly more 'activated'. This was brilliant and if I had to buy flux now I'd look for something similar - but beware, most are corrosive and for plumbing or soldering steel or stainless. The clue seems to be to look for rosin-free, halide-free, Lead Free