I wipe down the spring and the inside of the glass tube with a bit of silicone spray lube after cleaning. Makes the solder less likely to stick, and easier to remove if it does.
I have an anti-stick spray for welding; I imagine that would work well too. I always thought that spray was silicone based, but it explicitly says no silicones on the can.
I assumed the plating on the tips (which you have to punch through) was lead-free solder, but it doesn't seem to be (my lead-free doesn't take)? It's also not melting but instead starting to flake (break) off in places - is that normal?
Just checked my tip and it does look like the plating flaked off, however I remember that the solder never actually wetted to the tip, which surprised me at first, but it never impede the desoldering process as far as I can tell. Also if not wetting means the tip doesn't get eaten away as fast as on previous desoldering stations I had, then that's fine with me.
I desolder at 380 °C, seems to work best for me, it's fast and no clogging. I also accustomed myself to hold the trigger a little longer when I pull back, which also seems to help with clogging.
I find removing the barrel rather tricky(difficult). Is there a "trick" to doing this that I might be missing?
Yes, removing and putting back the tube is rather tricky. I tend to push on the sledge in order to take force of the latch and then pull down the latch. Then I push the glass tube and everything back towards the latch and pull the glass tube out from the front. Back in reverse.
You could try re-hardening by heating to red and quenching in water. It will then be brittle, so temper it by heating to straw colour and quenching again.
Yeah I tried that, well not entirely, I didn't bother with polishing and annealing ... let's just say it broke in one place while others were still ductile like copper ... I'm done with that spring
I don't think my solution for the spring will help others, but I had an old type spring lying around. That and a piece of aluminium foil in the back works just perfectly. No stuck solder lumps, no stuck solder on the filter and good continuous suction.
The plastic tube has some ridges in the back to hold the filter, the glass tube is supposed to be used with the new spring and the aluminium disc with the notches to hold back the filter. But I got the impression that the aluminium disc pressed against the filter and the build-up of the solder dramatically impacted suction after some time. So I'm using the glass tube with the old spring and an o-ring that just fits inside to hold back the filter ... I'm happy with it.