Soldering copper

Jewelry Discussion
21

Mindy… You are probably not getting it hot enough. When you have
something as big as I imagine a lantern is, it’s going to be a bear
to heat up enough to get the solder to flow. What kind of torch with
what size tip are you using? What’s the thickness of the metal? You’d
be surprised at how much heat you have to use on copper to get it to
flow sometimes. Copper just loves to soak up and luxuriate in the
heat. I do some sculpture pieces with scrap copper and I use an
acetylene torch with a tip big enough to melt ingots because it takes
that much heat to solder a 6 gauge wire a flat piece.

Are you sure it’s really copper that you’ve got there? It could be
something that looks like copper but is really an alloy that is going
to make it impossible to solder. Also, what kind of solder are you
using? (silver? paste?, etc.)

Do you really have to solder it? Why not rivet it. You could add to
the beauty of it with some nicely finished rivets. You could use
large gauge wire and form the heads. It could be super cool. You
could assemble it with copper screws and nuts which could add to the
beauty of the piece. You can get small copper screws and nuts at a
decent hardware store.

Sometimes I get an idea in my head about how something ought to look
and I will go to ridiculous extremes fighting to make it the way it
should be. When I give up and realize it’s never going to do what I
want and just go with what it wants, then I usually end up with
something I didn’t expect but like better. Now may be the time to
compromise on this item and think outside the box.

Mardel

22

Mindy, I would guess that your problem is the size of the copper
lantern. You are probably not getting the area hot enough for the
solder to flow. Larger pieces of copper radiate heat like crazy.
If you have a large annealing pan, try “burying” most of the lantern
in it and/or put some pieces of soft firebrick around your soldering
area, to try to keep the heat in. I can’t guarantee it will work,
but something like it might. Good luck! Judy Bjorkman

23

I am making a bracelet for my father out of copper and have never
worked with it before. I need to solder the copper, but am not sure
what solder to use. Any help will be greatly appreciated.
Nancy J…Nancy’s Fancies

24

You can use regular silver solder for copper. I recently took a
metalsmithing class and that’s what we used.

– Leah
www.michondesign.com
@Leah2

25

You can also buy a copper colored silver solder from Indian
Jeweler’s Supply. 1.800.545.6540.

Elaine Luther Chicago area, Illinois, USA Metalsmith, Certified PMC
Instructor Studio 925; established 1992
@E_Luther

26

Elaine. Have you used this solder? Is there anyone out there who has.
Is it really a color match to the copper?

I have had several supposed copper colored solders over the bench
over the years. None were close. Most were silver colored in the
end. I have used pink/rose gold solder when I need a small piece of
copper joined to another compatible metal.

Phos-Copper finishes up silver colored but it will take the patinas.

Bill

27 
     You can use regular silver solder for copper.

True; I personally prefer using pieces of hammered-thin brazing rod
because I prefer a seam with a gold color. The disadvantage is
the higher melting point of the brazing rod (higher than silver
solders). Take a look in the Orchid Archives for discussions on
using pre-1981 copper pennies as solder (to get a copper-colored
seam). Judy Bjorkman

28

Some notes (given that copper really is a beautiful metal)

I’ve got some copper colored hard solder from Monsterslayer, but I
haven’t tried it yet.

I got some copper colored hard solder that looks about the same from
the local jeweler supply (I forgot the name) in Mountain View CA, but
the color is off. Sometimes it’ll look OK after pickling.

Copper-bearing Brazing rods from the Bernz-o-matic company
(Available at Office Depot) also have off-colored joins.

Regular silver hard solder works fine but clearly shows a line.

Apparently, unless you are prepared to weld the entire thing,
getting the joins to look nice is pretty hard. You can sometimes get
good results by playing the torch against the joint until it’s almost
melted and then pickle it. Electroplating works. Jax copper plating
solution seems to work better on normal silver solder than it looks
on copper solder. Or you can accidentally drop steel into your
pickle pot and get a copper plating solution for free.

Copper is tricky to weld. I haven’t tried, but I know the woman who
built Egeria ( Firefall: Egeria Homepage )
out of copper. It is a little tricky because it is either liquid or
solid, with no gooey point like steel. I’ve had it melt on me
suddenly when I was trying to braze together thin wire. All of the
sudden, oops, you’ve got a puddle. :wink:

Otherwise, it’s a beautiful material. Relatively inexpensive, a
range of available beautiful colors, can be hammered and then
annealed without problems, etc. :wink:

Ken “Wirehead” Wronkiewicz \ \ /
http://www.wirewd.com/wh/ \ \

29

Nope, I’ve never used this solder, I know that it exists and where
to buy it.

Elaine Luther
Chicago area, Illinois, USA
Metalsmith, Certified PMC Instructor
Studio 925; established 1992
@E_Luther

30

The pre 1981 pennies are a metal that is also known as gilding metal

  • 95% copper 5 % zinc. Alloys containing 10% and sometimes even 15%
    zinc might also be called gilding metal but the distinctive copper
    color is gone. Indian Jewelers Supply sells the !5% zinc as more
    correctly red brass. I believe the 5% zinc stuff is more common in
    the UK, I have bought it in sheet form from Thompson Enamel:
    http://www.thompsonenamel.com. The melting temperature is just a
    little below copper. I have never been able to locate another alloy
    that comes close to matching the copper color. jesse
31

Dear All -

I’m trying to make a copper bracelet that has a decorative (copper)
element soldered to it. Right now the bracelet is just a 10"x2"
blank, well cleaned, and the decoration is a twisted pair of copper
wires that will go down the middle. I flattened the twisted pair
slightly to get better surface contact.

On my first try I fluxed the blank, placed hard solder pallions down
the centerline and tried to melt them… they never did puddle up,
even after 7 minutes of strong heat from my acetylene torch (Smith
torch, #3 head). I figured I might as well bond everything at once,
so I quenched it, sanded all the oxydation offf with 400-grit paper,
and tried again with the decoration in place on top of the solder. To
get good contact, I used binding wire to make sure nothing moved.

Still no luck with the acetylene (the copper blank and decoration
never even got red, unless I held the flame in one place for a long
time), so I switched to my propane plumber’s torch (“use a bigger
hammer…”) Obviously doing something wrong, because that didn’t
work either.

Finally, just to get something stick to something else, I took it
apart, cleaned & sanded, and tried again with plumber’s solder and
the propane torch. I got a bond, but it’s weak as paper, and I wound
up peeling the things apart when I flexed it.

I hope those of you experienced with copper can tell me what I’m
doing wrong, and how to fix it. Should I stick with propane and some
other solder? Do I need an assistant and have two torches going at
once? How can this be so hard?

btw, my heating technique at first was to treat it like sterling,
with the torch moving all the time. At the end, I was using more of a
brute force method of concentrating heat.

Thanks for any and all advice!

Kelley Dragon

32

Kelley,

I have soldered copper successfully with my prestolite several times.
Sounds like you are not getting enough heat from your torch.
Actually, a plumbers torch produces less heat.

Another thing to consider, are you heat from the bottom with the
piece on a soldering stand of some sort? Another method I have used
is to pin the piece to a charcoal soldering block to concentrate the
heat.

Hope this helps.
Peace
Richard

33

Kelley,

Make sure that everything is clean, flux everything, fuse solder to
underside of the wire and place on the copper sheet making sure that
the solder is contacting the sheet. Support each end of the copper
sheet on two charcoal blocks with a third charcoal block forming a
“U”. This will help to contain the heat. Heat from below the sheet
with your torch. Copper requires quite a bit of heat. First heat the
whole piece with your flame moving back and forth along the length of
the sheet. Then focus the heat at one end bringing it up to soldering
temperature and as the solder fuses to the sheet move your flame
along the length of sheet. This should work for you. I have my
students doing a lot of work with copper and brass and this is the
technique that we use successfully.

Joel Schwalb
www.schwalbstudio.com

34

Hi, Kelly,

You don’t say what gauge of sheet you are using, but you do, in
fact, need a bigger hammer. Acetylene is hotter than propane, but
you need a bigger tip. You have a lot of mass to heat up, and copper
must be heated fast, with a good amount of flux, get in, get it
done, get out, or it oxidizes and solder will never flow.

You are pretty unlikely to melt your copper, so bring as much heat to
bear on it as you can-- don’t hold anything back. By the way, the
binding wire will melt, so if you can figure out another way to
keep everything in contact, it might be better. Soldering weights, as
described in Charles Lewton-Brain’s book “Cheap Thrills in the Tool
Shop” are good.

Noel

35

Your problem is that you’re just not getting sufficient heat into
the copper to raise its temperature enough to melt the solder. Copper
conducts heat almost as well as silver so make sure you conserve as
much as possible by using a big flame (propane is fine) and
surrounding the bracelet with fire bricks to reflect the heat and
stop it leaking away.

Two torches and an assistant can help a lot. Have the assistant use
the large flame as background heat, while you use the concentrated
flame to get to the final fusing temperature. It can help if you get
the fire bricks good and hot before placing the bracelet on them. If
you haven’t raised the copper to the correct temperature within a
minute or so, the flux will burn and become useless.

Regards, Gary Wooding

36

Use LOTS of flux and more torches. It will take the equivalent of 3
number 3 tips, Air/acetylene to do that piece. You have to get the
whole thing hot enough so that as one torch moves over the solder, it
provides the last bit of heat to flow the solder. 10" x 2" is a very
large piece.

I have a compressed air/propane German torch from Otto-Frei for
these kinds of jobs. I love it. It will melt a coke bottle at 2 feet!

Heat. You need more heat!

Bill Churlik
www.earthspeakarts.com

37

Hi Kelley

Just so happens I have soldered some copper as large as the piece
you are doing, but I suspect not as thick as my material was.064 from
the hobby store and used as inlay for a jewelry box.

I wound up using one of the multi-gas heads for MAPP and Propane,
the one with the rubber hose like this;

http://tinyurl.com/86j9k

it has a very large flame diameter about 3/4" and only runs about $25
in this area. I found it much better than my plumbers torch for this.
Another thing I found this head good for was annealing silver wire
and plate with out the hot spots you could normally get using a more
concentrated flame. If you have the rose bud tip for the Smith you
might try that, but be careful of overheating, I have burned a spot
before completing what I wanted to do using a high intensity heat
source.

Terry

38

Kelly; I asume you fluxed the piece. You didn’t mention it so just
thought I’d ask. Secondly why the jump from hard solder to plumbers
solder? Why not try easy silver? You didn’t mention the gauge of the
copper, that can make a considerable difference. However I would
think a no.3 smith tip should be plenty big for what you are doing.
The acetylene is the hotter of the two torches I’d stick with that.
What are you soldering on? some ceramic surfaces are huge heat
sinks.you could try a screen heating from underneath or charcoal.
Hopefully this will give you some new options.

Dave Owen

39

Kelley, check the Orchid Archives for more on this subject.

The problem is probably that you have a large piece of copper and it
radiates heat like crazy. Make sure you’re working on a fluffy-type
firebrick, and surround the bracelet with more fluffy firebricks
(or, in other words, things that won’t soak up too much heat but will
reflect it back onto the copper). All of this is to keep the heat
from dissipating too rapidly. This should enable you to get the
temperature of the piece high enough to melt the hard solder.

Also, I think air-acetylene gives a hotter flame than propane.

HTH, Judy Bjorkman

40

Hi Kelley,

Several people have noted that you need lots of heat (bigger torch
tip!) and Judy Bjorkman wrote to surround the copper with
firebricks. I agree and further suggest that you place firebrick on
top of the surround, trapping the heat and creating an oven. I sliced
a firebrick into inch-thick slabs with a hack saw - very handy to
have for building an oven.

Also use the lowest temp silver solder you can find - extra easy
sold by Rio flows at 1207 degrees F. Someone also talked about
flowing solder onto the small piece (sweat solder), which is a good
idea. To improve the solder joint, put some fine sandpaper on a flat
surface, then rub the decorative piece across it a few times. You’ll
make the surface flat and create more contact between the two pieces.
Flow the solder on that flattened, rough area.

My last suggestion is to “double flux” - by that I mean after you
heat and dry the flux on your bracelet, place your small piece (with
the flowed solder) where you want it and put more flux (I like
Battern’s applied with a syringe)on the join and allow it to seep
completely under the small piece. Gently warm to dry, then pour on
the heat inside your little oven. To make the flux last a bit longer,
start by heating the outer edges of the copper (and therefore, the
firebrick), then when things look red hot, bring your torch to bear
on the area to be soldered. Copper takes a LOT of heat, and you’re
working with a large piece of it.

Hope this helps and the you are successful - let us know! Judy in
Kansas, who finally got the garden all hoed and raked and planted…
except the tomatoes. Got to get them in the ground tonight!