Help - my soldering iron tips are black!

[Bandit Mick]

I’m using non acidic flux, decent solder, wipe the tip regularly, and use my iron with care, ensuring it’s up to temperature before use and still the tip blackens over time until it won’t hold solder. What am I doing wrong? PS It’s a new tip cos the same thing happened to my previous one. I’m using an antex xs25 iron. Any ideas gratefully received - I only have 4 more wires to solder and I’m now at a standstill!

[Walkingthedog]

Shouldn’t do that if it is always covered in a thin layer of solder. Why are you at a standstill. Clean the tip with emery paper or a fine file.

I don’t use any flux apart from that In the solder.

[Bandit Mick]

Thanks WTD but I have been told previously that using emery paper takes off the fine ‘covering’ on the tips surface and ruins it. I’m at a standstill as I can’t power the track up until these last rails are joined to the bus. All wiring has gone well but not my soldering!

[Walkingthedog]

OK, let the iron heat up then wipe the tip on a damp sponge, I do this constantly while soldering. Once clean re-tin the tip. Are you getting insulation from the wire on the tip?

Don’t use extra flux, just make sure the two surfaces being soldered are absolutely clean and then tinned. Wipe the tip regularly on the damp sponge.

[Brian]

Hi
Wiping the hot tip onto a damp sponge during soldering is essential, as WTD has stated. Also I find an occasional hot tip wipe in one of these very useful too. Link to tip cleaner Others are of course available this is an example

[Bandit Mick]

Thanks again. I’m using a damp sponge regularly. Am now wondering if I’ve touched any sleepers with the tip. Will go and investigate. I always work carefully so am very frustrated.

[Brian]

Whatever you do DO NOT file or Emery cloth clean the tip You will remove the protective coating applied to the tip!

[Bandit Mick]

Thanks Brian I won’t. I haven’t touched anything plastic with the iron - neither wires or sleepers. I should have mentioned that as I used my iron last night the tip surface was reduced ie blackened from the edge. When I came to use it this morning the whole surface was black. I keep all working surfaces clean and always take my time yet every tip I use gets ruined. I’m obviously making a basic mistake but don’t know what!

[Bandit Mick]

Have just tried using the second tip from the set of 3 - a pointed one and that too has instantly turned brown and won’t hold solder.

[Tricky Dicky]

Badly oxidised tips are a real mare to restore. Files and emery cloth may remove the oxide quickly but will damage the iron carbide layer on your Antex irons tip. When I was still working our technician used to restore tips using a small brass wire brush in a Dremel or alternatively one of those brass brushes used to restore suede. Do ensure that the wires are brass and not simply steel plated to look like brass.

You can get a cleaning/ tinning paste similar to solder paste where you just push the tip in the paste which cleans off oxide and then tins the tip, but I find it is not up to dealing with Heavy oxidation and can often leave a dirty tip.

https://www.rapidonline.com/multicore-l ... oz-85-0630

Richard