Silver Soldering

[flintstone mop]

hello Radio!
I'm getting ready to lay down some radials and have heard wisdom floating around about corrosion of standard solder in a wet environment or near the ground for the copper tubing around the base of the vertical.
Any ideas on the material needed? I have seen what happens to regular solder connections exposed to MaNature. Any easy tricks?

Fred

[WBear2GCR]

regular 60/40 or similar solders are ok, but don't do that well when exposed to the ground... I'd be sure to try to coat them - non acetic acid cure silicon rubber would be my first choice on that.

The so called "refrigeration solder" is I think 96 tin and 4% silver and is higher temp may do a better job, assuming the copper wire is thick enough to support the extra heat needed.

Silver "brazing" is higher temp and may not be suitable for normal gauge copper wire because of the temp required  which may also melt the copper... that would have to be checked and probably the heat controlled carefully, but if it works would likely be the strongest and longest lasting joint that can be made short of resistance welding the copper itself...

These are only my seat-of-the-pants rantings...

                 _-_-bear

[Ed/KB1HYS]

Get a Mapp gas torch and braze em. Clean and then apply a spraypaint finish over the joint. Couple of coats ought to do. Bury it nicely

[flintstone mop]

Get a Mapp gas torch and braze em. Clean and then apply a spraypaint finish over the joint. Couple of coats ought to do. Bury it nicely

Ed , I think you re-connected some brain cells of mine. I DO remember soldering and painting with some Primer type spray, and held up well over the Winter.

Fred

[k4kyv]

Go to a plumbing supply shop and ask for silver alloy brazing sticks.  They are about 18" long and flat, about 1/8" wide.  No flux is required.  Just use a mapp gas torch.  Heat the copper to where you can see a dull red glow in low light.  No flux is needed.  Copper soaks up the stuff like a sponge soaks up water.  No need to clean the copper to a bright finish.  Just remove any scaly crud from the surface, and the rest will burn off with the heat. The only time I had any problem with the wire melting was when I was brazing my #12 copper radials to the ground strap. Just be careful not to heat the copper to an orange glow.

No need to coat the finished joints with any kind of paint or sealer.  After 25 years mine look just as good as the day I brazed them.

The brazing rods are not cheap, but not unreasonably expensive either, because they are widely used in plumbing.  It is against code to use lead/tin solder for copper plumbing because of the fear of lead leaching into drinking water and the  fact that the lead/tin solder deteriorates when in contact with water and wet minerals.

For my first radial system I built back in the stone age I used lead/tin solder.  I had to go out about once a month and re-solder the radials because the solder would turn into a white powder and the radial would literally fall off the bus wire.  The same thing happens when copper pipes are soldered with lead/tin.  The solder turns to  dust and the joint begins to leak.  Because of the volume of sales, the silver alloy is relatively inexpensive.