I have a brand new soldering iron, the tip turned black while heating on my first use, and now solder won't stick to it, it just rolls off.

All the answers in similar questions here tell me to stick solder to the tip but it won't stick because the tip is black. I have never used this iron and have been unable to tin it.

I've tried cleaning with a damped (not wet) sponge as several people suggested, but nothing comes off with several minutes of scrubbing.

How do I solve this chicken / egg situation?

A shot of the tip as requested/suggested

  • \$\begingroup\$ Dip it in water when on - use a wet sponge to drag off all the sh*t. Or maybe you've bought from a disreputable source? \$\endgroup\$ – Andy aka Dec 2 '15 at 23:15
  • \$\begingroup\$ It's from Maplin, a pretty large electronics retailer in the UK. I have literally just heated it to use it, the tip turned black, and now solder won't stick. Going to reheat it now and try the dip/sponge thing. \$\endgroup\$ – Hippyjim Dec 2 '15 at 23:31
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    \$\begingroup\$ "Dipped it in water". This is not what you want to be doing. It cools the tip right down and will harden the grot. You want to wipe it on a damp sponge. \$\endgroup\$ – Tom Carpenter Dec 2 '15 at 23:58
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    \$\begingroup\$ @Matt Young, no it hasn't. Similar questions that do not answer this one have. This is a brand new iron. I have never been able to tin it. It has been cleaned - there is nothing to clean. I know how to use stack exchange, but I don't know how to fix my brand new iron. \$\endgroup\$ – Hippyjim Dec 3 '15 at 12:12
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    \$\begingroup\$ Followup. I found with some research that brass sponge is pretty much a requirement for lead-free (I generally stick to leaded, because it doesn't suck). The rapid cooling of lead-free leads to cracking of the tip coating and rapidly degrading the life of the tip. Leaded, use a damp sponge; lead-free, use the brass thing. \$\endgroup\$ – Kris Bahnsen Dec 3 '15 at 17:41

As pointed out in the comments and other answer, you need to clean the tip.

There are two options for cleaning, depending on what you have, or what came with the Iron.

  1. A Compressed Cellulose sponge, which has been wetted with water. You want it to be damp, but not soaking wet. If it is soaking it just cools the tip down and doesn't help clean it. If it is dry, the sponge will burn, putting more crap on the tip.

Cellulose Sponge

Image from here

  1. A Brass Wire cleaning sponge. These are not the same as steel wool. Steel wool is an abrasive which will damage the tip (as will sand paper). The tips are made internally of copper which is great for heat transfer, but will be damaged/dissolved by the tin in the solder. To allow the tip to work, it is plated with Iron which will withstand the soldering process, and is key to ensuring the tip can be used. This plating is thin and can be easily damaged by abrasives, or scratching against things. The brass wire sponges are not abrasive, they are like the scrubbing pads people sometimes use for washing up. They look like this:

Brass sponge

Image from here

For both cases you need to do the same thing, basically just drag the tip across the sponge a few times (may only take a couple, may take a dozen, depends on how much grot is on there) at a sort of medium pace (like washing up really). You should see the tip start to go shiny and silver. Once it is, put some solder on, and then again wipe on the sponge. Finally put some more solder on (tin the tip) when not in use.

So why did it happen so quick? I can think of a couple of reasons:

  1. There was some coating on the tip to protect it when sitting on a shelf for ages. Not sure if this would be done - if it was tinned, that should be enough, but you never know.

  2. If it is not a temperature controlled iron, then who knows what temperature the tip is at - ideally it should be around 360-380°C, but the non-controlled ones can be anywhere, even as much as 450+°C. The higher temperature will cause the tip to oxidise from stuff in the air much faster. Hopefully you should be able to clean it off on a sponge. Then once clean always leave it

  • \$\begingroup\$ Thanks for the step-by-step. I bought a stand and sponge with the iron, and have given it a good clean but I can't be sure there's actually anything on the tip - nothing comes off and the tip colour doesn't change. It's midnight. I give up. \$\endgroup\$ – Hippyjim Dec 3 '15 at 0:02
  • \$\begingroup\$ @Hippyjim Could you post a close up picture of the tip at some point (given how late it is there, perhaps tomorrow). \$\endgroup\$ – Tom Carpenter Dec 3 '15 at 0:04
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    \$\begingroup\$ @Hippyjim are you using rosin-based flux, and a rosin-cored solder? Try putting some flux on the end of the solder and give that a go. If it starts sticking, alternate between cleaning and flux+solder. Hopefully this is a one-time affair for those particular tips. \$\endgroup\$ – rdtsc Dec 3 '15 at 0:58
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    \$\begingroup\$ Thanks - I used tip tinner (basically flux & a cleaner) and after a few tries, (heat iron, dip in tinner, let iron cool, heat iron, wipe on sponge, repeat) that did the trick. \$\endgroup\$ – Hippyjim Dec 3 '15 at 21:39
  • \$\begingroup\$ @Hippyjim, just make sure you are thorough in cleaning off the tip cleaner (tin the tip with regular solder a few times and wipe off). The tip cleaner contains quite a strong acid (why it works so well!), and if any is left on the tip for too long it will start to damage the tip itself. \$\endgroup\$ – Tom Carpenter Dec 3 '15 at 22:42

Clean the tip with a brass cleaning sponge.

Now, when you finish using it, store the tip with solder melted on it. Do not clean it off before you're done, the solder layer keeps the metal of the iron from oxidizing and easily cleans off next time the iron gets hot.

  • \$\begingroup\$ Thanks, but "store the tip with solder melted on it" - how? The solder rolls off, that's the problem I'm having. \$\endgroup\$ – Hippyjim Dec 2 '15 at 23:29
  • \$\begingroup\$ Please don't clean the tip with steel wool. It will just damage the plating and cause it to oxidise much faster - basically wrecking the tip. Clean it with a damp (not wet) sponge, or a brass cleaning sponge. Note that the latter is very different from steel wool, it is much coarser and won't damage the tip. \$\endgroup\$ – Tom Carpenter Dec 2 '15 at 23:38
  • \$\begingroup\$ @TomCarpenter Yes, thank you, I did mean a brass cleaning sponge. \$\endgroup\$ – Samuel Dec 2 '15 at 23:43

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