After a few hours practicing desoldering on old computer boards with a cheap RadioShack 40W (~800F) iron, I noticed the very tip started disintegrating. My preparations were instruction manual-perfect; before melting each contact I applied flux to prevent oxidation and improve wetting, and after, to clean oxidation and residue from the tip frequently, I vigorously brushed it with steel wool, which I now figure might be damaging given how abrasive it is and how thin the copper core's protective coating is. Or--without verifying with chemical calculations--I figured the strength of the flux's acid dissolved both the coating and copper, or only the copper after wool exposed it. Furthermore, from what little I've read, 600-700F of 15-25W irons are sufficient for most solder alloys. So is the flux's acid too strong when liquified; the steel wool too abrasive; the soldering iron poor quality or too hot; or a combination?
Thanks
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