[Elecraft] OT: Another quick question about solder...

[Ron D'Eau Claire]

A good "solder sucker" is also an excellent investment, as is some narrow
desoldering braid and a little rosin flux, either in a pen or small bottle.


Although elegant, the powered solder suckers are not necessary. A good
spring-loaded unit will do the job 99% of the time. They sell for US $10 to
$15. Where the sucker isn't convenient, the braid works FB. 

I also keep a little rosin flux around, but the only place I've used it in
conjunction with Elecraft gear is with solder braid to de-solder filled vias
and pads. Many have reported a few of those to clear when doing the mods in
question. I did. 

I don't put the flux on the board, but rather add some to the tip of good,
narrow solder braid, then press the braid against the via with the iron on
top. I raise the temperature of the iron to 750 - 800 F when doing that to
compensate for the heat absorbed by the braid. The flux mainly stays in the
braid, cleaning oxidation from the braid itself so it will more quickly wick
up the solder from the board into the braid. The action is obvious as the
copper braid turns silver with solder. 

That's how the vias on the left side in the VFO noise mod document were
cleared. In that case, the 1/4 watt resistor leads are a very close fit in
the vias and a thin probe pushed gently into the opened via compresses the
thin layer or solder remaining to provide the needed clearance. 

If you look closely at the photos you'll see a little flux on the board.
It's virtually clear - a sure sign it wasn't over-heated. That flux is
absolutely safe there; it will not damage the board in any way. Remember
that rosin flux is only active when it's up around the temperature of melted
solder, and if your K3 gets hot enough to melt the solder off of the boards
the flux will be the least of your concerns, Hi! 

As others said, a little practice before 'diving in' is an excellent idea.
If you don't have any scrap boards around, places like RadioShack have
little project boards that are an inexpensive way to get the feel of your
iron before working on the K3. 

Ron AC7AC