[Elecraft] Organic Rosin Core Solder

[John Bonk]

It's possible that it's not corrosion at all....could be the just the
leftovers drying up.  It's not showing up like that on the PCB though....you
have to catch it in the light just right.....

-John

-----Original Message-----
From: Jim W7RY [mailto:w7ry at centurytel.net] 
Sent: Saturday, May 14, 2005 2:07 PM
To: John Bonk; Elecraft at mailman.qth.net
Subject: Re: [Elecraft] Organic Rosin Core Solder

I would think you could use a good solder sucker and suck all the bad 
solder off the board.

Then re-do all joints with the correct solder.

Are you sure it's really corrosion?  Seems odd that the solder would 
corrode. Solder is for soldering brass, silver, copper, tin and etc... Why 
would it corrode the elements that it's designed to work with?

What is the stated purpose for water soluble flux in led/tin solder?

Interesting discussion..

73
Jim W7RY
K2 4914



At 01:56 PM 5/14/2005, John Bonk wrote:
>Just a friendly warning to those who may not know the exact origin of their
>solder.  I used a Kester solder that was labeled "organic rosin core" on my
>K2 (only 75% of the RF board) while I was waiting for a re-supply order to
>come in.
>
>
>
>Fast forward one week:
>
>
>
>Minus one sloppy joint, my K2 fired up and was putting out the expected
>power during part three of alignment.  Big whoop of satisfaction follows.
>Completed kit build with no issues.yet.
>
>
>
>Fast forward two weeks:
>
>
>
>Turned on the K2 to do some listening, upon hitting the tune button, I see
>the High Current warning.  After pulling apart the K2 again, I notice that
>75% of the solder joints on the RF board seem to be suffering from some
sort
>of corrosion.  Attempted to clean small portion with alcohol, very little
>luck..showing strange resistance values across the board.
>
>
>
>Three hours later:
>
>
>
>After two and a half hours of pulling my hair out, I decided to do another
>check of the solder to make SURE that I didn't make a mistake.  A bit of
>digging turned up the ORGANIC=WATER SOLUBLE.  The values I'm seeing and the
>corrosion of the RF board support this finding.
>
>
>
>The first attempt was a q-tip and water.  Second attempt was distilled
water
>and a toothbrush to help the process.  Neither has proved helpful and I'm
>still showing strange resistance values from the collector to ground on Q6,
>7 and 8, high current warning on keying.  Voltage checks show within specs
>for RF board during receive.
>
>
>
>So now I sit with a defunct K2, any suggestions for what I can try before I
>order K2-Part Deux would be appreciated.
>
>
>
>Lessons learned:  Throw away all unknown solder before you start.  Don't
use
>organic core solder.
>
>
>
>John
>
>KD7ZYR
>
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