[Elecraft] K2

[Don Wilhelm]

Mike,

If you have only limited experience soldering, check out the Soldering 
Tutorial on the Elecraft website.  Most problems are caused by poor 
soldering, followed by poorly stripped and tinned toroid leads, and that 
followed by misplaced components.

A quick insight on soldering - the old thinking of using a minimum 
soldering time to avoid damage should be discarded with modern 
temperature controlled soldering stations - that was for the old days of 
non-controlled irons that got very hot.
We now have boards with thru-plated holes and components that will 
withstand soldering temperatures for at least 5 seconds.  I normally use 
a temperature of 750 degF.

Watch for the solder to flow as you solder.  It should wick out 
completely onto the solder pad and the component lead in 2 to 3 
seconds.  If it takes longer than that the iron is too cold, if shorter, 
the iron is too hot.  Larger leads and solder pads connected to the 
ground plane are exceptions and are expected to take longer.

While a highly reactive solder flux (like Kester 44) is OK, IMHO it 
leaves a flux mess.
I use solder with a mildly reactive flux (Kester 385) and there is very 
little solder residue.

Do *not* clean the flux except in areas that have been reworked several 
times, and then clean up with alcohol on a swab.  Do *not* flood the 
board and get residue under components where it cannot be removed except 
by de-soldering the components.
If you do attempt to remove the flux, make sure *all* of it is gone.  
Flux is not conductive, but when combined with flux removers, any 
residue left may develop conductive paths when exposed to normal 
moisture in the air.  If you see 'whitish' rings around component leads, 
the flux and remover residue is still present and can cause problems later.

73,
Don W3FPR

On 6/2/2016 6:51 AM, Mike via Elecraft wrote:
> A K2 kit is on it's way.  Although I do have some experience  soldering, it
> has been 30+ years and I am open to any suggestions as to  equipment
> needed.  I have a Hakko FS-951 soldering station. I have seen  various mechanisms
> for holding the circuit boards while working on them.   Any other tips
> and/or caveats are more than welcome.  A retirement project,  hopefully to be
> completed by the time the sun comes back in a few  years. :)
>