Desoldering *usable* plumbing fittings

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Awl--

For 1/2" to 1 1/4" copper pipe fittings.

Possible to desolder *and* be able to re-use them??
Worth the trouble for the various fittings, T's, unions, etc?  1 1/4 unions
are expensive!

Any special techniques beyond heating/wiping, heating/wiping?  Wipe w/
cloth, steel wool? With, w/o flux?
I think I've done, mebbe once, and it was a pita!

Btw, I found, at Home Despot, something called Tinning Flux, which lightly
tins the surfaces `*before* you actually add solder.
I think this is pretty neat.  Any opinions? I would imagine it cleans as
well as non-tinning flux, but I haven't compared.

Thanks!
----------------------------
Mr. P.V.'d
formerly Droll Troll



Re: Desoldering *usable* plumbing fittings

Proctologically Violated=A9=AE wrote:
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unions
w/
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lightly
as

I've used that flux, it works well, but it's not a replacement for
proper cleaning of tubing and fitting before assembly.  If you've got
clean surfaces, either the tinning flux or regular flux+solder will
work for tinning.  If you didn't have flux or solder at all and were
tooling up for a one-time fixit job, I'd suggest the tinning flux.

As to your other question, unless the fittings are absolutely green or
physically damaged, there's no reason they couldn't be reused.  If it's
recovered scrap from demolitions, just use a propane torch to heat up
the joints.  As you say, new copper fittings are getting pricey these
days and I don't think the quality is what it was.  I had to pick
through the bins the last time I bought fittings to find some that
didn't have defects.  Only possible downside to recycling fittings
besides having to look them over well is that there may be some lead
solder on them, environmentally a no-no these days.  Practically,
there's probably not enough remaining that it would leach out, but I
thought I'd just mention it.

Stan


Re: Desoldering *usable* plumbing fittings
Kris, I remember just heating them up and wiping the exterior with steel
wool, or twisting in an appropriate tube brush. It leaves the part shiny
and ready to reuse. If you couldn't reuse a part, then when you had to
break a joint, you would have to replace EVERYTHING.

GWE

Kris wrote:

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Re: Desoldering *usable* plumbing fittings

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unions

Do you run a lathe and mill?   If so, are you aware of 3 cornered scrapers?
Perfect for cleaning out solder residue while the fitting is cold and easy
to handle.   Takes a little time, but works well.    Use a file for exterior
surfaces. I always brush with a wire brush made for fittings when finished,
or abrasive strip cloth for exterior fittings.

Harold




Re: Desoldering *usable* plumbing fittings
Fittings in good condition are eminently reusabe.  Just pull apart and, when
reusing them, clean the excess solder out with a quick heat  and a slap on
something to remove the excess solder so that you can fit the pieces back
together.
As to the "Tinning flux", it is merely a flux which you can spread easily
over the copper rather than something that puts solder on the copper.  There
is flux that has solder chips included in it if you want to go that way with
a one-step tinning solution but the flux and solder isn't cheap.

--
Why isn't there an Ozone Hole at the NORTH Pole?



Re: Desoldering *usable* plumbing fittings
Proctologically Violated wrote:

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Yes, it's possible, in fact it's quite easy and straightforward to do. If
you can get any old lead solder off it's fairly sensible for DIY usage.

A professional plumber won't do it though, for several reasons - legal
regulations - the fittings won't look new, and the client is paying for new
fittings - the time it takes to desolder and clean them is too long, do you
know what a plumber gets paid? - the supply of used fittings is unreliable,
and a reused fitting is slightly less reliable than a new one - plumbers buy
in large quantities, when end feed 1 1/4 unions are no longer expensive,
they become quite cheap [1], - and last but not least, in the UK at least,
it's illegal to use lead in plumbing solder and the old fittings will have
lead solder on them.



--
Peter Fairbrother


[1] maybe 35c each, translated from UK sizes and prices, with a 40% trade
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Re: Desoldering *usable* plumbing fittings
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Yes, no, maybe, and it depends.  Mostly, if you heat it up, and give it a
good sling, the liquid solder will fly off and give you a nice clean piece.
If they are bent at all, they can be cranky.  Depending on the value of the
piece, and the criticality of the application you have to be the one to
decide to reuse or toss.  For noncritical stuff, though, they can be reused
easily.

Steve



Re: Desoldering *usable* plumbing fittings
Proctologically Violated wrote:
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I've done that many times. (If you asked SWMBO she would say of me, "Can
you spell c-h-e-a-p?")

On several occasions I found it extremely difficult to get the joints
apart, after they were heated to well above the melting point of soft
solder. Twisting a fitting while pulling on it to try and get it to come
off would produce a squeek like the door hinges from "Inner Sanctum".

I asked metallurgist about that and he told me it was due to the
formation of intermetallic compounds over time, which had a higher
melting point than solder.

Jeff


--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

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Re: Desoldering *usable* plumbing fittings
Since copper will slowly dissolve in molten solder, this causes both pitting
of copper soldering tips and increased melting temperature of solder which
joins copper pipes. Too much heat makes it worse, as does long heating
times. The best technique is to heat the joint carefully just until the
solder melts, then separate the parts quickly.
Don Young
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Re: Desoldering *usable* plumbing fittings
Jeff Wisnia wrote:


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Yep.

There's another similar phenomenon that's quite interesting, but perhaps not
directly relevant, diffusion brazing.

You braze a joint and keep it hot for an hour or do. Note that braze metal
necessarily has a lower melting point than the base metal, otherwise it
would ebe welding. The lower-melting metals in the braze diffuse into the
base metal, and eventually the melting point of the metal where the brazed
joint was is as high as the original base metal (it can actually even be
higher).


And the same Cu3Sn (or Sn3Cu, I'm too drunk to remember) molecules (*shhh..)
(though they are a problem in diffusion brazing - come to think of it, they
are also a problem in disassembling plumbing fittings - darn those Cu3Sn
molecules!) are often involved, to bring it right back on topic!


--
Peter Fairbrother

Love is old, love is new
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