ERSA soldering iron tip suddenly un-tinnable

I think that you have to treat the tip as having reached the end of its life.

I have used tip cleaner (sort of waxy stuff in a little pot) but the effect doesn't last long).

MK

In my subjective opinion 0.4 mm pointy tips are easy to irreversibly destroy when they are hot and the point is tapped against a hard surface.

I use a non-pointy, 1 mm bevel (i.e. sloped) tip for SMD down to 0.65 mm pitch parts such as TSSOP.

Sometimes it helps to use an even bigger tip (e.g. spoon), and also relying on flux to make the solder easily float around and cling to metal without bridges across pins being formed.

At 0.4 mm pitch parts (like QFN) I often switch to reflow tools (in my case, preheater+hot air) but still feasible with a soldering iron and even with large tips and flux. A very fine pointy tip could be used there, but personally I wouldn't keep it regularly attached to my soldering iron; the very fine pointy tips still have their uses, but more niche purposes I feel.

It looks like the tip got too hot.

Or perhaps some foreign material was soldered onto it.

This can also happen unintentionally if you accidentally touch something while soldering.

If I want to burn off the scale, I use solder wire (>1mm, preferably lead-tin) with plenty of flux.

For cleaning, I use a sponge soaked in water, not copper wool.

Apply solder several times, wiping in between, until a layer of solder remains on the tip.

The correct melting point should be observed.

Soldering with Ersa soldering stations has always been a challenge for me.

...too hot, too cold, too...; the temperature was rarely transferred directly to the tip.

In my opinion, the alloy used for these Ersa tips is not optimal (I've been soldering with soldering irons and stations since 1976).

Hi Geralds,

Yes I wondered if the tip had got too hot. 
So what I've tried:-

I just very carefully scraped the tip with a scalpel blade being very gentle so as not to cause the blade to 'dig' in or remove metal.
The dark grey material does seem to come off and the tip returns to looking like the 'wider section' that solder DOES stick to.
However the tip still refused to tin at first.
As you said though continuous wiping and feeding copious solder onto the bit with it pointing down (making a large droplet of molten solder that envelopes the tip)
does seem to improve things and I managed to get part of the tip to tin again.
From what you have said, I guess I should press on cleaning and soldering over and over an see if the situation is resolved?

Like you I have been using solder stations since the 70's but of course these were crude 'curie' controlled ones like Weller's.
We are now a long way from the old ANTEX and even SOLON irons from the early 60's when I started soldering..lol!

Thanks everyone for your thoughts/hints/tips, please keep them coming

Dave

 RE: Reviving an oxidized tip 

The business end of a soldering tip is plated with iron to protect the copper and allow solder wetting. When solder is scraped off the iron (by brass wool) it can expose small areas that start to oxidize. Solder does not stick to rust. To revive the tip, it is necessary to remove the rust and immediately tin the tip with solder. Rust can be uneven, forming micro-pits which are hard to see and hard to remove. The iron layer is also pretty thin, so aggressive rust removal can remove the iron, which is needed. Tips can usually be revived enough to be used for non-critical soldering, but at some point it is not worth the fight.

The reason I don't use brass wool is that it seems like it might be able to scrape the solder down to bare iron. (I do not have any proof)

I did a video of trying to mechanically refurbish oxidized tips....

https://youtu.be/i-bmQsPNSQ0

dougw said:

The reason I don't use brass wool is that it seems like it might be able to scrape the solder down to bare iron. (I do not have any proof)

No. It's too soft for that.

Hello for the last 15 plus years i have been using Hako 926  iron with knife tip on daily basis, 

I admit i have used on melting plastic and as a chisel into potting mix, 

cleaning with wet pad and rarely using little pot that came with it 

putting temp to max on some military connectors, that was ok,

what i found last year that destroyed the tip with in days was using iron with solder with high silver content

and i had to crank up the temp because of the silver 

Sorry I only use Metcal. I have been using them for 25 years; the tips last forever.  And on eBay, about $35 or less, 

NEVER USE BRASS THINGS to clean the tip, only damp sponges, 

 I have a TIP for my Ungar Imperial Iron from high school (8 decades ago)!!  still clean and usable.. ~~ Cris H.

proof? did you read the NASA spec. only sponges 

Perhaps you're using the wrong type of flux (too strong, plumbing type) and it's corrosive to the plating on your tip, or the temperature is somehow too high (e.g. temperature feedback thermistor sensor is broken) and the heater is "running away" overheating the tips.

- Gough