[Boatanchors] (de) soldering question

[J. Forster]

Likely oxide of the solder. Fresh solder on the joint helps, but braid recently
wetted with rosin based flux does wonders.

BTW, I forgot to suggest buying a sucking machine used. There are older models
than the PPS-5 also. They show up at fleas for about $100, but may need some
internal cleaning or a kerosene or mineral spirits flush of the air pump.

-John

WA5CAB at cs.com wrote:

> Norm,
>
> I'm sure that John is correct about the solder wick although I have never used
> it much.  I've always preferred and used one of the spring-loaded mechanical
> pumps like the Soldapult or the smaller Paladin (but have been recently
> seriously considering a desoldering station for use on major jobs).  But even
> with the vacuum gear, on old sets (OK, there aren't any other kinds discussed
> here), and especially ones that have been MFP'd, even after mechanical
> cleaning of the joint before heating I get consistantly better results if I
> flow just a little fresh solder into it before applying the vacuum.  Even when
> molten, the old solder often still appears somewhat dull gray and grainy or
> lumpy.  A little new solder and it turns bright and molten and much more of it
> leaves the joint with one "suck".
>
> I don't know for certain whether the reason is an original difference in the
> older solder or oxidation effects (I'd bet on the latter) but the small amount
> of fresh solder technique always seems to work.