The advice about replacement of the section of tubing is the easy repair, is
correct.

Soldering copper tube and fittings isn't difficult to learn. Buy at least a
couple of handfuls of fittings and a section of tubing and practice on
fittings facing in all directions.

Use all the proper standard practices.. cut the tubing with a tubing cutter,
deburr the end ID burr, shine the tubing end and the inside of the fitting
(should actually produce bands of fine scratches for the capillary action),
emory cloth is commonly used for the tubing ends and a properly-sized round
wire brush is the easiest method for the fitting openings. Special round
wire brushes are sold for shining tubing ends, too (these brushes work like
battery post cleaners).
Keep the shined ends clean.
Apply a thin flux coating to both parts immediately after shining the solder
areas and fit the two parts together.

The proper temperature isn't highly critical, and the end of the solder
touching the fitting near the connection will be the best indicator of the
proper temperature. The flux will sizzle as the temperature gets close to
the solder's melting point.
The flame is applied to the back side to give the best visibility while
watching the joint draw in/wick-in the molten solder.
Feed in the solder, remove the flame and carefully swipe the joint with a
clean, damp cotton cloth/shop rag. Extinguish the fire if you sat the lit
torch where you shouldn't have.

Safety.. I always try to have a reliable trigger-spray bottle full of water
within reach, and a fire extinguisher only a couple of steps away.
Specially-treated mats are available for using as a shield over wood and
other flammable materials near connections to be soldered. I find thin
aluminum roofing flashing to be very versatile for using as heat shields.

After doing a couple of practice joints, take 'em over to the bandsaw or
grab a hacksaw, and cut the joints and peel them open to see if full
coverage is attained on the two mating surfaces.
Practicing on joints that are oriented in different directions will be
effective learning aids.

Valves and some other fittings can be a bit trickier, but learn the
essential basic steps first before proceeding to the other items.
The most used fittings will probably be els and couplers. Master these, then
practice on other items. Sections of tubing can be sweated to some new
valves for practice now, but for future use.. compressed air and soapy water
can be used to check for leaks. Since there's no water pressure in the
practice piece (which would make a mess if it failed), some light hand
pressure force can be applied to the tubing ends to test for strength of the
joints, followed by air pressure testing. When the valves are needed, just
use couplers to fit the ends in place.
Valves are generally soldered in the open position. The trigger-spray water
bottle can be used to cool valves and larger components quickly.

All systems should have valves at each point of use, at the minimum. Trying
to get a line emptied when it's connected to 50 feet of line above is a
nuisance, but if you can shut a nearby valve, the section of line drains
right now.
Some valves have a port with a small knurled cap to drain lines to aid in
draining, and bleeding air from lines.
Placing some extra valves at random locations in a system can be a great
convenience in the future when repairs (leaks?) or expansions are needed.

--
WB
..........


"Pete C." wrote in message
er.com...

Karl Townsend wrote:

I've got a pin hole leak in a copper pipe on my hot water heat sytem.

Murphy is my partner. So, of course, the leak is right where the pipe
goes through the floor and you can't get at it. A proper repair is
going to mean removing the radiator above, cutting out a whole section
of pipe and replacing.

To avoid this job, does anyone suggest some sort of goo to just apply
to the surface of the pipe? Other easy fix?

Karl

Cutting out a section of pipe and replacing it *is* the easy way to do
it. Once you have some experience soldering plumbing you'll realize this
and just cut and replace the offending section rather that spending 3X
the time trying to band-aid it.

You need to at least partially drain the loop so there is no water in
the area you are working on. Get one of the little fiberglass heat
shield cloth squares to use to back the work area and avoid torching the
wall, floor, etc. Have a damp rag available to wipe excess solder from
hot joints for neatness. A pair of channel-lock type pliers is essential
if you try to un-solder any existing connections.

They make couplers that do not have the center dimples / grove and allow
you to slide them fully onto a piece of pipe before aligning with
another pipe and sliding over the joint. Make a mark on the pipe so you
will know when the coupler is centered. A good lead-free paste flux and
some abrasive cloth are essential in getting a good joint, especially on
existing pipe. Use lead-free solder as well, likely all you'll find
these days anyway.

Don't skimp on pipe cutters, get something decent like Rigid and in both
full-size and the mini ones which you can use in close quarters. One of
the mini-hacksaw handles is also helpful for areas too tight for even
the mini tubing cutters. Don't bother trying to use a propane torch,
only use MAPP or MAPP equivalent and use a good trigger-start torch like
a Bernz-o-Matic TS4000. Don't be tempted to use oxy-acetylene, it's too
hot for soldering (good for brazing), plumbers sometimes use
air-acetylene, but not O/A generally.

Use only type L pipe, not the thinner type M. If you have a pinhole leak
and it's not from mechanical rubbing damage, you may well have a lot
more places ready to go unless you are lucky and it's a manufacturing
defect in one spot. BTW, it's a "hydronic" heating system.