[Moon-net] protective coating for soldered joints outdoors

[Lance Collister]

peter blair wrote:
>  I keep on having problems with soldered joint corrosion on the junctions between 141 cable inners ( which are silver plated ) and  my 23cm and 13cm folded dipoles which are made from copper rod.  I cut slots in the ends and thus clamp the wires as well as soldering but I find that the joints are corroding. They are made with resin cored solder, not acid flux.  The joints are out in the weather under protection that keeps direct rain off them. Im looking for some compound to coat them with after soldering. 
>   In the absence of other ideas I will  try just clear varnish.
>  Any ideas ... this is my tropo system I should add  but these reflectors are usually the place to find a good answer.
>  thanks 
> 73 Peter G3LTF 
> _______________________________________________
> Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html
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> 
Hi Peter,

If you look at the dissimilar corrosion tables, you will see that it is 
recommended to use LEAD BEARING solder to join silver to copper.  I realize this 
does not address your weatherproofing issue, but the dissimilar metal probelm is 
something that needs to be addressed separately from weatherproofing. 
Weatherproofing is also needed, but it does not solve a dissimilar metal corrosion 
problem.

Good luck and VY 73, Lance

-- 
Lance Collister, W7GJ (ex: WN3GPL, WA3GPL, WA1JXN, WA1JXN/C6A, ZF2OC/ZF8)
P.O. Box 73
Frenchtown, MT  59834  USA
QTH: DN27UB
TEL: (406) 626-5728   URL: http://www.bigskyspaces.com/w7gj
2m DXCC #11, 6m DXCC #815