(updated :: see 10th post)
so this tip is fairly newish, about 1 month
previously i have seen this reaction before, but i didnt try to question the why of it.
there is another thread talking about fluxes (so many kinds
) , some acidic, some not, etc ... but flux are suppose to oxidise stuff to clean stuff ... so it is reactive
notice the layer behind the tip is a rough shiny surface when new, that is turning a rusty color, it looks like a reaction to acid. because it happened gradually in a few days without soldering lol (i did do a few rounds of soldering work, some acidic flux was involved). if heavy on flux use, normally it turns chocolatey like a stain, but this looks like iron rusting
anyone seen this before?
i will be getting some new ROSIN flux maybe next week. so likely i will try it without the acidic flux i have been using to see if it does the same thing
... or maybe its the acid from the "glue" ...
the felder flux is indeed powerful, which give me the impression of "i like it" ... but now looking at this scenario ... it seems too acidic? lol
(if anybody handles fibre glass sleeve, the fibre ends are suppose to go thru some kind of sintering with a torch so that the ends melt onto each other to prevent breaking off. fibre dust it is a lung/skin/eye irritant)