The green stuff on a PCB

[mackrackit]

Just the thought of somebody coming anywhere near my tips with a rasp file is well and truly an

Duncan

I can understand that, but look at it this way. Someone had to grind, file, rasp, or use a small lathe to make the tip in the first place. I have an old iron that has the hard to find tips too. A friend of mine makes them for me. I am not sure of the alloy, it is a hard copper of some kind. When he is finished shaping and threading I clean the tip and drop it in a lead pot to tin. Works good. But that is just me.