I am interested in buying some sheets of copper and making some fountain
creations. I would have to cut and shape copper, and join some seams.
Would the best way be to solder them? Is there a special process? Do I use
flux? Lead solder? Lead/tin solder? Rosin core? Give me some hints.
Also, I want to create some copper tooled insets for door panels and
decorative work. It is stunning, and weathers great. How would I join
those seams without getting too big a HAZ that is visible forever, and that
Suggestions and sites appreciated greatly.
"Steve B" wrote in
Not too much help here I fear pal...I too had the thoughts of using some
sheet copper for ornate items, I ended up going to a roofing manufacturer
for prices on the things but they were way too much for my pocketbook...
Welcome back by the way!...email me will you, I've lost your addy.
Steve, years back I did quite a bit of work with copper sheet and
flashing, with thicknesses as large of 0.125" for large heatsinks. This
was around 30 years ago, and for the most part we used 50/50 tin/lead
solder, and fluxed the work with a liquid acid flux sold under the name
of "Tinner's Fluid". I'm not sure that this is still sold, but then it
was a liquid acid flux available at every hardware and plumbing supply
store. The combination produced very strong and durable joints, but
required that all traces of the flux be removed after completion of the
The downside was that visible solder, while bright at the outset,
tended to darken through oxidation over the passage of years.
Were I doing it today and if long term appearance was an issue, I'd use
one of those new silver based solders using for plumbing, along with a
suitable flux. The other alternative would be a silver solder and a
Mapp Gas flame, or an oxy/acety torch. This will give you a joint that
is arguably stronger than the copper itself, but perfection of such
joints requires considerably more practice than simple soft solders.
Brazing is another technique that you may want to consider. Like a hard
solder (silver solder for instance), you'll need a specialized flux and
a high temperature torch. Your application does not sound as though you
would need to resort to such an extreme (a fountain), so I would start
with a conventional soft solder and flux, then proceed to more extreme
techniques only as the needs of the application demanded.
Hope this helps.
Steve B wrote:
You might want to ask over at sejw. Solders real easy. Typical plumbing
flux is zinc chloride. proly wouldn't want to use any acid fluxes.
You could also consider not soldering, but doing something like what Idid in
a closet: Plywood walls, 1/8 x 1" strip over the seams. Looked really
cool--well, at least in my closet!
This is for larger areas tho.
Soldering edges, corners, etc. sort of leaves you no choice. May consider
silver solder. Or even brazing!
Or epoxy. :) :)
But here's the bigger problem w/ copper, as a decoration.
Yeah, it's beautiful, but to *keep* it beautiful is constant
maintenance--unless you just want the patina, but then, as a roofer pointed
out to me, you gotta really like *green*!!
The solution is to coat it, somehow, but that always struck me as cheating,
and ultimately temporary/vulnerable.
An alternate solution is to use bronze sheet. Will knock yer socks off, it
ages *really really nice*, w/o patina, fwiu. Different shades of bronze, as
well, altho I don't know if you will have many options when buying sheets.
Not sure of the available gauges, either, below 1/8.
In machining parts for my Folly, I use brass only for practice, bronze for
the real parts. Big diff.
Keep in mind there are all types of copper as well, roofing copper being the
cheapest and softest. But you can buy all grades/hardnesses in sheets.
Hmmmmmmmmmmmm. A TIG is on my Christmas list. I'll have to wait. I have
done a lot of SS TIG, and am 6g TIG certified. But, I never really thought
of it. How do you think it would do on a 90 corner where the edges are just
folded up and you have to fusion weld the corners? On a lap, it would
probably be better, and I imagine one could turn down the voltage to control
I have never TIGged copper. Does it have hot shortness as aluminum does?
Mainly, some of this copper is going to be used to hold water in fountains,
and it needs to HOLD WATER. I think I could solder, or even epoxy it, but
TIGging sounds like a very plausible alternative.
Thanks. Please post answers.
I'm not a welder but I have to pretend to be once in awhile. I'm not
sure what all the terms mean.
If by hot shortness you mean that heat is pulled away then yeah.
I welded up a short length of "hex tube" by milling 60 degree edges on
1/8" sheet (I think it was) clamping to a form, and just fused the
seams. I think I had to start the run hot then back off some once it
started to flow. I don't know how thin of sheet you can get away with
welding though. Just practice.
"Randy Replogle" wrote
Hot shortness happens when a metal is heated to it's melting point, and has
a tendency to collapse under it's own weight leaving just a hole. Aluminum
is notorious for that. I guess I'm asking do you get a lot of instances of
burnthrough when doing copper?
I've only welded it a couple of times and it's been awhile, but I think
maybe so because I remember having to keep the torch moving fairly
quickly. Sorry I can't be much more help. I haven't seen anything from
Ernie Leimkuhler here for awhile but he's probably got good answers. You
could Google the group archives. He may have given me ideas once upon a
Regular lead free plumbing solder and paste flux will work great. Do
abrade the copper before soldering to remove oxides. If you have a
joint where one sheet laps another by 1/2" or so then tinning before
soldering is best. You can buy flux with solder granules in it for
tinning and soldering. The silver bearing plumbing solder is pretty
strong but even stronger is a product called "Super Sil-Flo" that's
sold at hardware stores. It's sold by Forney. It has no silicon in it.
There's another similar product called "Sil-Phos" that is similar and
may contain silicon. Anyway, these are brazing alloys suitable for
copper and copper alloys and is self fluxing on copper. So clean
joints result. The color is close to copper too. You do have to get
the copper about twice as hot as with plumbing solder though. Another
nice feature of the stuff is that you can use it to build up areas,
like fillets. After soldering the copper if you clean it well, and I
mean the whole sheet or piece, it will patinate the same.
If there is any chance of someone drinking water contained in one
of these creations, then you should use lead-free solder. "95-5"
is sold at hardware stores for water pipes. It works about as
well as 60-40 tin-lead solder, but is quite a bit stronger. You
generally use a paste solder for things like this, and there is
no flux in the solder. There are paste fluxes and Zinc Chloride
liquid fluxes. You may want to experiment with both to see what
works best with your torch technique.
The HAZ is not going to be all that different once you clean the
whole piece. The solder will not take the same patina, of
course. If you have to make visible seams that must blend, then
something like TIG might be the way to do it, although TIG'ing
copper takes a lot of heat. If the seams can be hidden, then
don't worry about a HAZ, just clean all flux residue off.
Yes. I've only done a few pieces, and they were mostly 1/8" and
thicker. I did see that the entire piece pretty much heated up
to the same temperature before I started to get any fusion. So,
once you get it hot and started to weld, you had to take it very
easy on current and keep the arc moving. You definitely couldn't
build up a big puddle and then drag it along like on steel.
This "hot short" business seems to be a misnomer to me. I think
the problem with both these metals is that the heat conductivity
is so high that you cannot get one hot spot with all the
surrounding material significantly cooler.
Well, solder is a good choice, you have no chance of the whole
thing melting down into a puddle. There is also phosphor-bronze
brazing rod that is made for air conditioning and such work, and
has a much lower melting point than pure copper. It is still
high enough that you can melt the copper if your torch flame gets
a bit out of your control. But, you have a temperature reading
by color of the glowing metal, so once you know the color you
need to heat to, you can control it quite well. Generally, no
flux is needed with this braze. You can't do this with the
standard propane-air torch. At least MAPP-air, or Acetylene-air
as the plumbers use, or oxy-acetylene. Some of these
phosphor-bronze brazes can be close in color to the copper, but
that doesn't mean the patina will blend in.
TIG should also make a very reliable joint. The very first piece
I did came out very well. If you have ever successfully TIG'ed
aluminum, copper should be no trouble. I've made a few barely
passable test welds in auminum, so maybe the copper was even easier.
This is a low-temperature brazing material specifically intended for
joining copper. It's much stronger than solder, flows well, and
you'll get a fairly decent color match. This stuff runs at lower
temperature than the usual phos and sil-phos stuff used, and it can
cope with fitup not as good as the other materials require.
You might be able to get a free sample. That's how I know about it
-- the guy at the welding store handed me a couple of sticks of it and
said, "try this, Don, I think you'll like it!" (He was right.)
Interesting stuff Don,
You have any idea of it's strength?
I do 1/8 scale locomotive boilers outta copper, 6 to 8 inch Dia... Been
using Uniweld 1000 PhosCopper for years... if this is strong enough it
woudl make things a bit eayser..
I weld a lot of 0.043 inch copper. I use DC TIG with deoxidized copper
rod. If you are already a skilled TIG welder you should not have a big
Note that the current requirements are high, on the order of 1.5 or 2
amps per 0.001 inch. I set my TIG at 90 amps to weld 0.043 inch thick
Copper presents many of the same welding challenges as aluminum, fairly
easy to burn through, highly conductive of heat. However, copper is
less likely to crack, in my experience. I tend to think of them as
similar in terms of the challenge of welding them.
Phos-copper rod is often used to braze copper for fountains, no flux
needed, but you will need oxy-acetylene (or oxy-propane or oxy-MAAP) to
braze it. Phos-copper rod works slick, the color match is not bad
unless you grind it to bare metal. Much easier to get watertight joints
with phos-copper than TIG welding. Fast, lower skill process.
With TIG welding, the color match is very good, but not undetectable. I
don't do a lot of patina work, so can't comment on how the weld takes
patina vs the base metal.
Steve B wrote:
Just going off on a copper tangent here. I recently built a glass block
window and used copper flashing around the edges. I sealed it up with
clear silicone caulk, and noticed that the caulk made it turn green
right away--instant patina. The green isn't a problem, but I'm curious
why the silicone caused this reaction. Is there an alternative product
that won't have this effect?
On Mon, 20 Nov 2006 16:17:25 -0600, with neither quill nor qualm, Jedd
Haas quickly quoth:
Most silicone caulks give off acetic acid while curing. Plain acrylic
caulk wouldn't have done that.
-- I'm in touch with my Inner Curmudgeon. --
Comprehensive Website Development
Most older generation RTV silicones evolve acetic acid during cure. GE-II
silicones evolve methanol. I would presume you used a 1st-generation
silicone, and the 'patina' is actually copper acetate. It's very soluble in
water and hygroscopic -- so it's going to attract water during humid times,
and might even continue to corrode for a while before all the acetic acid
has consumed as much copper as it can.