[Elecraft] Broke my K2 :(

[Alan Bloom]

Don is exactly right about this.  When I was at HP/Agilent, the company 
directive was generally not to try to clean the rosin with alcohol.  
(Rosin-core solder was used only in rework.)  The rosin contains an acid 
to help with the soldering, but the acid is locked up inside the rosin 
where it does no harm.  Once you dissolve the rosin with the alcohol it 
spreads out and can cause leakage paths between connections.  Just leave 
the rosin there; it does no harm

HP did clean production boards after going through the wave solder 
machine.  But that used a water-soluble flux and the cleaning process 
was thorough enough to completely remove all traces of flux.  That's 
basically not possible using alcohol and cotton swabs on rosin.

Alan N1AL


On 7/14/2021 5:20 PM, Don Wilhelm wrote:
> When I have cleaned boards with IPA or other cleaners, I apply the IPA 
> only in a small spot with a q-tip and then blot it with a paper towel 
> to help dry it - do not flood the board.
> I generally do not recommend cleaning boards, solder flux is 
> non-conductive and will normally not cause a problem.
> I only clean when the solder flux residue is really nasty as might 
> occur with Kester 44 solder.
> Use of a solder with a mildly reactive flux (Kester 385) will reduce 
> the need for cleaning the board - there is almost no residue.
>
> If you do choose to clean the board, make sure your cleaning work is 
> complete.  While solder flux is non-conductive, the flux plus the 
> cleaner may be conductive leading to resistive leakage paths. If you 
> can see any white stuff on the board, you have not done a complete job.
>
> 73,
> Don W3FPR
>
> On 7/14/2021 6:41 PM, Peter Eijlander (PA0PJE) wrote:
>> Yes Jerry, isopropyl alcohol does this!
>> I once cleaned a working print of a GPS receiver with isopropyl 
>> alcohol and it stopped working. Letting it be and trying it again 
>> next day turned out it worked perfectly again.
>>
>>  From then on I leave a PCB to rest after cleaning to have the IPA 
>> dry out completely...