I have some 1/2 inch type M copper pipe and 4 90* elbows that I'm
sweating together for practice. I've cut some 8 inch pieces and
yesterday was able to solder one end of each ell to 2 tubes. It took
a few extra tries but I was able to draw the solder into the joint
pretty well. There was alot of smoke created, white and brown. I'm
using yellow canister (Map gas?), cleaning the joints with emery
cloth, flux and using lead free solder.
Today I can't seem to get the solder to draw in. I've prepared the
joints as before and am attempting to create a square with the tubes
so this time the ell is connected to 2x 8 inch pieces. I also notice
that even though the solder is eventually melting it is not drawing in
the joint, and when it hardens it has a yellow color to it.
Is the yellow color significant and does it indicate a problem with my
technique? Can there be a noticable difference between yesterday and
today as relates to how quickly the joint heats up, as today I have 2x
the amount of tube to heat?
The solder should melt the second you touch the heated metal with it,
leading me to think that you are not heating the joint hot enough. Put more
heat on a freshly cleaned and fluxed joint and see if that helps.
Are you also using a MAPP torch? You won't get a proper flame if you try to use
a bottle of MAPP
gas with a propane torch.
Where are you applying the heat? A common mistake is to heat the joint between
the pipe and the
fitting. Always heat the fitting only: the pipe will get plenty hot enough
Also, make sure to clean and flux both the fitting and the pipe.
On Tue, 7 Feb 2012 14:41:58 +0000 (UTC), Doug Miller
You always heat the biggest heat sink first - which in this case is
the PIPE. The fitting is smaller and thinner and heats faster. I
always heat the pipe where the fitting ends, then move the torch to
the fitting just as I touch the solder to the joint.
On Wed, 8 Feb 2012 04:05:55 +0000 (UTC), Doug Miller
You need to heet them BOTH - and getting the pipe hot takes more
heat - so you heat it first, then when it is just about at the right
temp to melt the solder you move to the fitting, the whole assembly
reaches melt temp at about the same time, and the solder draws into
the joint neet as you please, with no grapes or bubble-gum hanging
from the joint and no leaks. No overheated fittings and burned flux
On Wed, 08 Feb 2012 16:54:57 -0500, email@example.com wrote:
If it works for you continue. In reality, you don't heat the pipe
directly. I used to work in a department that made heat transfer
coils. The guys used to solder or braze thousands of joints per day.
Never did they heat the tubing first. Always the fitting.
What they did though, was custom make torch tips with two flames at 45
to 60 degrees heating the joint, flame facing up. While soldering one
joint, it was pre-heating the next.
Some coils were automated for soldering. Tubes had a slight flare and
the elbow sat inside with a ring of solder. They too heated the
joint, not the tube.
Tubing and copper pipe are 2 totally different situations. Tubing is
thin like the fitting. Even Type M, which is the cheap light crap with
the red stripe is heavier than most fittings, while the blue L and
green K type are a LOT thicker. In a lot of heat exchanger units the
manifolds/fittings are significantly thicker/heavier than the tubes.
You should stick to subjects you know something about; this isn't one of them.
I just miked a piece of 1/2" copper pipe and a 1/2" coupling: the pipe wall
measured 0.023" and the
wall of the fitting 0.040". So tell me, which is the larger heat sink, the pipe
or the fitting which is almost
seventy-five percent thicker than the pipe?
On Thu, 9 Feb 2012 02:45:34 +0000 (UTC), Doug Miller
I guess it depends on the fitting. and you are measuring the
cheap-asses Type M tubing (and poorly at that - it's .028" wall
thickness) - while L is 040 and L is .049. (assuming half inch -
anything bigger is thicker)
A straight coupling ( 1/2") measures .028", and an LB is thinner
because it STARTS at .028 and is stretched to fit over the pipe, as
well as being stretched on the outer radius. At least a LOT of them
are. I have a 3/4" street elbow in my hand, and it is as thin as .025
and as thick as .035"
3/4" K is .065", L is .045", and M is .032"
So how 'bout YOU stick to what YOU know.
On Fri, 10 Feb 2012 02:06:00 +0000 (UTC), Doug Miller
No, the OBVIOUS conclusion is we are either measuring different
fittings or YOU can';t measure. - and you are a cheapass who uses
inferior M copper. I never use M - and for me, with the fittings we
get here, my method works - and works extremely well. I'm not saying
you have to do it my way - Unlike you, I don't say anyone who
dissagrees with the way I do things (or don't but think others should)
is wrong, or stupid, or inferior.
Different strokes for different folks - but if someone is having a
problem doing things the way they are doing them, and asks for
information, finding out what works for others can be valuable. The OP
can try the way I recommmend and see if it works for them. If it does,
good. If it doesn't, no big loss and no skin off my teeth, or yours.
You don't want to try it? Too bad, so sad - doesn't bother me at all.
You already know it all so you will never learn anything off this
group anyway - so you may as well crawl into your hole under a bridge
somewhere and congratulate yourself on knowing all there is to know
and being perfect.
On Wed, 08 Feb 2012 21:00:03 -0500, firstname.lastname@example.org wrote:
Quite right, but I never said anything about copper pipe did I? I'm
talking tubing. The same .022 and .025 tubing used in most
refrigeration, unit heater and transfer coils in water and steam
systems. Return bends were made from similar tubing.
We made aluminum finned coils from 6" x 6" x 1" up to 48" x 180" x
24". About 90% was copper, but we did some brass and cupro-nickel for
high pressure in ships.
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