On 2008-01-30, Ross Herbert wrote:

Your desoldering tool (like most) is probably fitted with a small diameter tip
(approx 0.8mm - 1.00mm inside diameter)

Yes.

designed for sucking solder from around small gauge component leads
and IC pins where the tip make full peripheral contact with the
board. When the solder melts around a pin all the air passes solely
around the lead and maximum effect is achieved inside the through
hole.

Well, it does this pretty well with a real vacuum pump attached
instead of the "desoldering station pump".

When you try to suck solder from around pcb mount switch terminals you have to
do it in stages because the tip doesn't have the closest contact with the pcb
for most of its tip periphery. There is usually a fair gap between the switch
terminal and the side of the mounting hole and when the solder melts and the
suction starts it will pull solder from only a small section of the hole before
the rest of the solder cools due to the air passing. There will be much more
solder around a switch terminal as well so it may take several goes working your
way around the pin.

Somehow, to my amazement, usually one "suck" was enough per pin. The
pins were too thick to fit inside the tube, so I had to approach it
from the side, and yet, it worked out.

My Hakko desoldering station has good suction but when it comes to desoldering
switches and other large terminal items I usually prefer to use my old manual
Soldapult. These only take one or two goes to remove all solder.
http://www.stanleysupplyservices.com...spx?pn=114-202

I am confused as to how it works, do I need a separate source of heat
for that one?

thanks

i