[TowerTalk] Silver Solder

[Paul Christensen]

Use approved grounding clamps and conductor size to satisfy local code and NEC.  Then augment the system with silver-soldered connections.  

Paul, W9AC

Sent from my iPhone6

> On Aug 7, 2015, at 12:51 PM, Jim Lux <jimlux at earthlink.net> wrote:
> 
>> On 8/7/15 9:24 AM, mike stokes wrote:
>> Hello
>> 
>> I need to improve my radials and lightning protection.  What Silver Solder
>> is best for the job and where is a good place to purchase it ?
> 
> I'm not sure silver solder (called silver brazing these days) would be appropriate for lightning protection.  It's certainly not what the code requires for grounding (approved clamps or exothermic welds), although I think it's a reasonably workable solution.
> 
> For RF purposes (e.g. your ground radials), though, silver brazing isn't a bad idea. It's rugged, it's easy (assuming you have the right equipment).
> 
> I doubt that the specific alloy makes a lot of difference. What you're really looking for is that the melting point is higher than that of tin/lead, and that it's mechanically more rugged. I've used a variety of "hard solders" from the local hardware store. Typically, they are around half silver (price varies with silver content). Pretty much anything will work with copper/brass (if you're brazing steel, you need to be a bit more careful in material selection).  A typical alloy is something like Silvaloy 355 which is about half silver, 1/5th copper, and the rest zinc and tin.  No cadmium. At least that's what I found out in the garage that still has a label on it.. I'm not a pro welder, with ovens to keep my rods dry, records of material certs, etc.. Others on this list ARE much more knowledgeable and may have some recommendations on the best alloys.
> 
> As with all "melt metal to stick metal together" things, the right flux and the right heat source is probably more important than the actual metal you're melting.
> 
> I use the solid white paste flux, and I've used both a oxy-mapp rig (one of the ones with the two "propane torch" sized bottles) and a oxy-acetylene rig (with a fine tip on the torch).  Either works. The bigger rig (with big bottles, either oxy mapp or oxy acetylene) is nicer because you don't worry about running out of gas. If you could borrow or rent the rig, life is easy.
>