Tin-lead solder was used for more than 40 years for potable water copper
plumbing inside structures. It has now been replaced (by code) with
lead free solder to remove lead as a potential trace water contaminant.
The lead in solder exposed to the water can be leached into the water
stream.
Current building codes now prohibit soldered joints underground, even
with the new lead free (usually Sb/Sn) solders. They must be brazed
with forged fittings.
Re 63/37 Sn/Pb "electronic" solder exposure to soil and weather - my own
experience is they last about 5 - 7 years in the atmospheres where I
have lived. I didn't have any in ground contact. The recommendations
to protect the soldered joints with liquid tape or something similar
make a lot of sense to me. Any information on the long term corrosion
resistance of the common replacement solders (Ag/Sn, Sb/Sn, etc) would
be very interesting.
It is also relevant to the discussion that Cu building flashing is
soldered with 50/50 Sn/Pb bars and is intended to last a long time. I
don't understand the chemistry of eutectic (63/37) solder degradation,
but it is clear that more Pb is helpful and 5/95 Sn/Pb is (was) used for
corrosion protection of steel. Lead flashing for chimneys lasts a very
long time.
I've soldered some Cu flashing using the standard 50/50 bars, a MAPP
torch, and flux made for flashing. This flux is much easier and less
hazardous than using muriatic acid.
The Cad-Weld etc. copper thermite use has been previously covered in the
discussions about ground wires/ground rods as code requires lightning
protection connections that are not able to be inspected to be
welded/brazed. see http://www.gacopper.com/BrazingRod.html for some
recommendations on brazing rods.
Grant KZ1W
On 3/24/2011 9:34 AM, David Gilbert wrote:
> Moisture is a big issue for standard lead-tin solder and over time it
> can degrade a typical solder joint to the point of failure, although I'm
> sure it also depends upon other chemical influences. Whether that would
> happen in any of our remaining lifetimes is a point of conjecture.
> There is a reason, however, that lead-tin solder does not meet code for
> soldering copper water plumbing.
>
> Dave AB7E
>
>
>
> On 3/24/2011 6:02 AM, David Jordan wrote:
>> Hmmmm,
>>
>> I've had some wire antennas up in the air for over 20 yrs. Used rosin-core
>> solder. Surface looks weathered but below the surface the solder is stable,
>> connection good. Location is high acid, salt, blown sand/dust, relatively
>> high pollution. YMMV
>>
>> I use silver solder on pressurized copper tubing HVAC connections but don't
>> waste it on antennas and the melt temperature is higher risking compromise
>> of the small wires. Never saw the need to use silver solder for antennas so
>> I guess preferred is in the eye of the beholder, as in hold still so I can
>> get a good solder joint!
>>
>> 73,
>> Dave
>> Wa3gin
>>
>> -----Original Message-----
>> From: towertalk-bounces@contesting.com
>> [mailto:towertalk-bounces@contesting.com] On Behalf Of don daso
>> Sent: Wednesday, March 23, 2011 12:39 PM
>> To: TowerTalk@contesting.com
>> Subject: [TowerTalk] soldering radials (or any outdoor connection)
>>
>> The preferred method is to use Silver Solder.
>>
>>
>> _______________________________________________
>>
>>
>>
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