[sdiy] Solder won't stick to old PCB

[flightofharmony]

> > Ingo, your iron was probably too
> > hot to start with, the solder you describe will definitely have a
> > higher
> > melting point than your usual 60/40 lead alloy.
> 
> I didn't say I was having any problems with soldering :-)
> However I do have a problem: when using a very fine tip, the solder
> sticks well on component wires and PCB traces but not on the tip. It
> seems these very fine tips you only need for SMT work wear out really
> quick. The Weller "tip activator" helps a bit, but only for a short
> time, and it smells very bad...
> 
> No this is not a lead-free solder problem. It happens with leaded
> solder too.
> 
> Ingo

I don't recall if you mentioned or not, but what type of flux core are you
using?
I've noticed similar problems when soldering (using a Weller WES51, and ETR
tip for SMD), but it depends on the flux.
Both no-clean and water-soluble fluxes have this issue - the no-clean(Kester
245) is the worst, while the water-soluble(Kester 331) is a little better. I
have to use tip tinner every 20 or so connections with the 331, but that's
about it. The 245 is a pain.
I have no problems when using the classic Kester "44" rosin core though.
Before turning off the iron, I'll tin the tip with the "44", wipe it on a
brass wool pad and re-tin it. This keeps the tip in good condition.

Unrelated, but a handy trick I've found: the 331 flux is VERY vigorous, and
I've noticed that tips that don't clean up very well with other solders
become smooth and shiny-tinned after tinning with 331 & wiping.

Best regards, 

~flight
flight at flightofharmony.com
http://www.flightofharmony.comdropmix.xs4all.nl/mailman/listinfo/synth-diy