[Elecraft] [K3] - mods and solder

[David Ferrington, M0XDF]

ok, thanks for that, the latest RS stuff says:
Crystal 400 60/40 Tin/Lead EN29453, S-Sn60Pb40E

the Elecraft HAGC mod instructions for SMD say
63/37 or 60/40 Sn/Pb-content rosin-core solder, 0.015" to 0.025"  
diameter

so my S-Sn60Pb40E looks like thats the same alloy, not sure what the  
'E' means.
it's 0.7mm, which is 0.027559055" (ok, conversion widget!)
so although thats a little over (by 0.002!) that would look to be ok.

I failed to mention that I have done a fair amount of soldering in my  
time (taught as an electronics apprentice and worked in defense  
electronics for 8 years), so don't have a problem with soldering.

I just didn't know about the make up of the solder - but of course  
'clicked' after your post.

Thank you Gary
73 de M0XDF, K3 #174
-- 
Those who walk bravely through life, unafraid of loss or failure,
find that they very rarely lose or fail.



On 2 Apr 2008, at 11:27, Gary Hvizdak wrote:
> At 0315 EST on Wednesday April 2nd 2008 David Ferrington (M0XDF)  
> wrote ...
>
> ... I KNOW some of you know a lot about solder. ...
>
> --
>
> Hi Dave,
>
>    Your 60/40 solder could possibly result in what are referred to as
> "cold" or "disturbed" solder joints.  If I were you I'd only use  
> that stuff
> for non-electrical hobby projects such as leaded glass, and jewelry.
>
>    For best results I would suggest eutectic solder which is an alloy
> composed of 63% tin and 37% lead.  In addition to it's having a lower
> melting point, it also transitions pretty much instantly from a  
> liquid to a
> solid, without any intervening "plastic" state.
>
>    In addition your .048" solder is much to thick for SMD work.  I  
> suggest
> something in the neighborhood of 0.020", plus or minus 0.005".  (You  
> need to
>
> match your solder size to your task, being careful that the solder  
> isn't too
>
> fine as this could result the flux burning off before it does its  
> job, which
>
> is to clean the surfaces to be soldered of any oxidation.)
>
>    Regarding the flux, your best bet is a mildly activated rosin  
> core flux.
>
> FYI, here mildly activated is a reference to the temperature at  
> which the
> rosin melts (so that it can do it's job).
>
>    DO NOT USE WATER SOLUBLE FLUX AS YOU WILL VOID THE WARRANTY OF  
> WHATEVER
> IT TOUCHES!  WATER SOLUBLE FLUX IS HIGHLY CORROSIVE AND  
> HYDROSCOPIC.  NEVER
> EVER USE IT WITH INSULATED WIRE (ESPECIALLY STRANDED) AS IT WILL  
> WICK UP
> UNDER THE INSULATION WHERE IT CAN'T BE COMPLETELY REMOVED.  OVER  
> TIME IT
> WILL EAT RIGHT THROUGH THE WIRE!
>
>    SIMILARLY DO NOT USE ACID CORE SOLDER!
>
>    No-clean fluxes are okay, but they have a higher activation  
> temperature
> and you should have some experience with them before using them on  
> something
>
> as expensive as the K3.  The advantage of no clean fluxes is that  
> they only
> leave about 3% of the residue left by a traditional rosin flux.
>
>    BTW, I won't even go into the subject of whether or not to remove  
> the
> flux and how to go about doing that.  If you are interested you can  
> see my
> previous post on this subject in the archives here ...
> http://mailman.qth.net/pipermail/elecraft/2005-November/049886.html
>
> 73,
> Gary  KI4GGX
>
> P.S.  I don't know a lot about solder, but I work with someone who  
> does!