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Soldering copper


#1

Hi, Noel-

There was a thread a few months ago on using old pennies (early
1960’s or prior) for soldering copper. You can search the archives
for the exact year. Apparently the copper alloy used for pennies in
the olden days had enough zinc or whatever to make it an effective
solder for copper and the color does not contrast. You might consider
giving that a try. – Lee Einer

http://members.cox.net/appealsman/


#2

IJS carries a wire solder, called Fos-Flo #7, for copper.

Item number is #801-WS, melt 1310f, flow 1350f. Composition is 92.75%
cu, 7.25% phosphorus.

About 2 bucks for 20 feet.

Dan Woodard, IJS


#3
 IJS carries a wire solder, called Fos-Flo #7, for copper. Item
number is #801-WS, melt 1310f, flow 1350f. Composition is 92.75%
cu, 7.25% phosphorus. About 2 bucks for 20 feet. Dan Woodard, IJS 

Dan-- Thanks! I actually have some of this (though I’ve misplaced
it). Oddly enough, it is not copper-colored, though it makes less of
a contrast than regular silver solder. I’m still hoping to manage to
fuse, if only “because it’s there”.

On a somewhat related subject-- I’ve been trying to figure out the
actual differences among soldering, brazing, and welding. The terms
are not used consistently. Dictionaries say one thing, every other
source says another. Anybody out there have the definitive (literally
;>)) word on this? Thanks!

–Noel


#4

Hi Noel,

 I've been trying to figure out the actual differences among
soldering, brazing, and welding. The terms are not used
consistently.

I helps if you know what industry the speaker is most familiar with.
Sometimes the terms are more or less industry specific.

Soldering in the sheet metal & electronics industries means heating
something with an electric soldering iron or a large copper
soldering iron that’s been heated in a fire of some kind, then
applying a ‘solder’ made usually made of some alloy of tin. It
usually melts around 500F. Fluxes are used.

In the plumbing trade soldering is usually done to copper & brass
usually using a propane fired torch, a flux & a tin based solder
melting around 500F.

Solders used in the previous industries tend to be supplied in a
wire or bar form. In the electronics industry the solder usually
contains a non acid flux. The plumbing & sheet metal trades
generally use a seperate flux, either a liquid, paste or bar.

Soldering in the jewelery trade usually implys using a an alloy of
the metal being soldered (silver, gold, platinum). The alloy usually
melts at a lower temp (but not much) than the material being
soldered. A flux is used to prevent oxide buildups that would hinder
the flow of the molten solder. Solders are available in sheet, wire,
powder & paste. The paste solders usually have a flux mixed in the
paste.

In most other metal working industries, this type of ‘soldering’ is
called ‘brazing’. In the ferrous metal industries, the ‘solder’ used
is generally a brass of some type.

Welding in the non jewelery industries is the joining of multiple
pieces of the same metal by heating them to their melting point
usually with the addition of a filler material of the same metal. In
some cases fluxes are used. The heat may be applied using a gas/oxy
torch, an electric arc, laser or other means.

In the jewelry trade, this method of joining metals is called
fusing.

Generally, soldering can be differentiated from welding in the way
the connection is made. In soldering, the connection is by means of
a different material that engages the minute surface irregularities
of each piece & upon solidification holds them fast. The material
used as the solder melts at a much lower tgemperature than the
materials being soldered.

Brazing (& jewelery soldering) uses a material that’s different (but
in jewelery, not much different) from the materials being brazed.
Typically it melts at a relatively high temperature, but not as high
as the metals being joined. It’s method of holding the materials
together is basically the same as for soldering.

Welding however, melts each of the pieces being joined & the molten
materials co-mingle on the atomic level. A filler of the same
material is usually added. In the event that there are small
differences in the makeup of the materials, the welded area is a new
alloy of the materials. However it’d take some sophisticated
analysis to differentiate.

In the jewelery tade this is called ‘fusing’. A filler may or may
not be used.

Sometimes soldering is refered to as ‘hard’ soldering or 'soft’
soldering. Generally, the ‘hard’ soldering requires a heat over
1000F while ‘soft’ soldering can be done around 500F. Hard soldering
provides more mechanical strength than soft soldering.

It’s also possible to solder & braze dissimilar metals together.
This is very difficult if not impossible by most welding techniques.

Dave


#5

Greetings Dan: I have been looking for copper solder for some time.
I’m not familiar with IJS - would you please elaborate address with
full business name, phone number (toll-fre if posssible) and location
and whether they ship to Canada.

Regards,
Joe Bokor
@Joe_Bokor2


#6
 Soldering copper IJS carries a wire solder, called Fos-Flo #7, for
copper. Item number is #801-WS, melt 1310f, flow 1350f. Composition
is 92.75% cu,  7.25% phosphorus. About 2 bucks for 20 feet. 

I’ve tried this solder with limited success. it tends to sizzle and
sparkle rather than run into my seams. i use my regular sterling
solder technique and flux… anyone have any insights??
thanks Mark Kaplan @mark_kaplan


#7
      Soldering copper IJS carries a wire solder, called Fos-Flo
#7, for copper. Item number is #801-WS, melt 1310f, flow 1350f.
Composition is 92.75% cu,  7.25% phosphorus. About 2 bucks for 20
feet. 
I've tried this solder with limited success.  it tends to sizzle and
sparkle rather than run into my seams.  ...

G’day. That kind of solder is sold in this country as SILPHOS and
is used extensively by plumbers as the majority of houses in NZ are
plumbed with copper pipe, although recently built houses are being
plumbed with black polyethylene, and others are changing to it.

I have used silphos and it is not a bit like any of the silver or
gold solders, but is more like brazing; bronze welding. The liquid
silphos does not flow into interstices like jeweller’s solders, but
the job is done by building up a filet, very much like steel welding.
The resultant weld with silphos is a kind of dark purplish, and if
you are inexperienced, a bubbly weld. to me it looks ugly; I would
not use it on any piece of jewellery. For joining copper to give a
far less poor looking finish I would use silver solder or at a pinch,
brazing.

My own opinion about definitions is that there isn’t an ‘official’
one. Any method of joining metals using the same metal is what I
would call welding. Thus, joining platinum with platinum, gold with
gold, steel with steel I call welding. Any method of joining
metals by using a metal alloy which has a low surface tension when
liquid, is a solder. Ok, so there are things which don’t quite fit
these criteria, but anyone got a better one? Or are we getting
’lawyer mentality’? – Cheers for now,

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#8
    On a somewhat related subject--  I've been trying to figure
out the actual differences among soldering, brazing, and welding.
The terms are not used consistently. Dictionaries say one thing,
every other source says another. Anybody out there have the
definitive (literally ;>)) word on this?    Thanks!                

Noel, this question came up back in 1999 and at that time, in
response to a similar request, I wrote out my understanding of the
differences among soldering, brazing, and welding. For what its
worth, I have copied my response from the archives rather than
referring you to look up the article. The following is a copy of my
response:

Guy Audette: You do have a greater problem than most of us herein
the States since you have to interchange with two languages and the
terms used in both do not have the same meaning. I will try to set
down my understanding of the terms you’ve listed and hope that it
will at least provide you with a jumping off point.If further
clarification is necessary please feel free to E-mailme direct.
Terminology can indeed get in the way of accurate communication when
attempting to explain the various way in which we join metals
together. In general, both silversmiths and jewelers call the
process “SOLDERING”. However,according to Handy and Harmon,that term
is incorrect. If metals are joined using heat attemperatures above
1100F it is properly called “brazing” Metals joined below 800F is
termed “soldering” But the term soldering is in such common
usage, that, when we refer to metal joining in our field,we mean
joining at temp.above 1100*F. The more technical term would be
brazing. Soldering is the joining of metals with the use of a
metal(usually an alloy of the metals we are joining)which we call
solder, and the application of heat. At the temperatures discussed
the grain bounadries of the metals to be joined are opened up and
the filler metal(solder) penetrates those boundaries without fusion
of the base metals. Fusing is the joining of parts by bringing
their contacting surfaces to a molten state with heat so that they
join each other by penetration of their atoms without the use of an
intermediary metal such as solder. A common example is the fusion of
a bezel when doing granulation. Welding is a fusion process in
which the welding rod (fillerrod) and the two edges of the joint are
melted together tobecome one. Not a jewelry procedure. Spelter is
an alloy of brass and is used as a solder for non-precious metals
such as steel and brass. (To add to theconfusion) this process is
also called brazing, but the procedure also requires temperatures
above that which is used for so called soft soldering. Note: When
using soft solder, you cannot flush grind the solder without
materially weakening the join, since soft solder, unlikehard silver
solder, does not penetrate the grain structure of themetals being
joined. I hope I haven’t added to the confusion and in some small
way there has been some clarification.

J.Z.Dule


#9
      Soldering copper IJS carries a wire solder, called Fos-Flo
#7, for copper. Item number is #801-WS, melt 1310f, flow 1350f.
Composition is 92.75% cu,  7.25% phosphorus. About 2 bucks for 20
feet. 
    I've tried this solder with limited success.  it tends to
sizzle and sparkle rather than run into my seams.  i use my regular
sterling solder technique and flux...  anyone have any insights??
thanks  Mark Kaplan   markaplan@hotmail.com 

I have not tried it, but it has occurred to me – has anyone tried
using just the regular solder that radio hams and suchlike use(d) to
solder their wires? (before the days of printed circuits, etc.) It
does, of course, have a silvery color, but so does Fos-Flo #7. I
think it’s mostly lead, with a low melting point.

Margaret


#10
    I've been trying to figure out the actual differences among
soldering, brazing, and welding. The terms are not used
consistently. 

Howdy Noel and others; I am a beginner metalsmith and come from an
electronics background so it was a little confusing to me also. I’m
comfortable with the definition that ‘soldering’ (soft soldering-as
in electronics) occurs below 840deg. without the melting (puddling)
of the parent metal(s). Brazing (‘hard’ soldering - like for most
jewelry work) is above 840deg. without melting the parent metal(s).
Welding (fusing) involves melting or ‘puddling’ the parent metal. I
suppose these activities may or may not involve the use of flux or
’cover’ gases?

Carl
1 Lucky Texan


#11

I recently used a tig torch to weld copper, with both sil-phos
brazing rod, and with ordinary copper wire. Now there’s a colour
match. A tig torch is also called Heli-Arc by some, it’s an electric
arc process where the arc is surrounded by inert argon gas.

About the relationship of soldering, brazing, and welding: Soldering
can be considered like glueing, but at low heat like 400-600.
Brazing is like the same, but high enough heat to get the material
red hot. It’s sometimes called hard-soldering because the solder, the
brazing rod, is hard like brass, not soft like lead-tin solder.
Welding is entirely different; it’s like melting two ice cubes then
refreezing them as one cube. They become one. Of course this can
all be described differently on a molecular level. I am a
professional welder certified in several diffent procedures.

Ron


#12

Hi everyone, I am new here and I am having a HUGE problem. I am
trying to make a copp er lantern and cannot solder it! I know that
this is a jewelry site but I figure that you guys would know how to
solder the copper. I have made copper jewelry before and have not
had this problem. I cannot get the solder to stick for some reason.
I have sanded the copper and put on a little flux and it just won’t
work! Please help me because this is a Christmas gift and it needs
to be done quick! Thank you for taking the t ime to read my post and
I eagerly await your reply.

Mindy


#13

Maybe there is some finish you didn’t quite get off?? Acetone and/or
alcohol wipe,… sometimes when the copper is pretty “old” theres
that problem too (found that one out with our old plumbing!!) Or maybe
you aren’t getting it quite hot enough over a big enough area,… if
it keeps popping,… clamp the sucker good with some C-Clamps with
flux and some flat solder between your seams and really heat it
up,… Good luck. Martina


#14

Hi Mindy, A Santa Cruz weathervane makers soldering advise for larger
projects is to use a double headed torch tip so that you can heat
from both sides of the seam at the same time. The copper is
apparently a good conductor of heat, so the heat you need to solder
with goes throughout the piece.

Marta in stormy Sacramento


#15

I have had the same problem soldering copper. Through my research,
even outside of Orchid, I came to the conclusion it was not enough
heat. I needed a larger flame.

I was trying to solder onto a piece of pipe, about 8 inches long,
1.25 inch in diameter, and I have a small torch. No matter how long
I tried to heat the copper, I couldn’t solder. I bought a tip that
could heat the pipe. It was big enough but it sounded like the
space shuttle launching and my fire detectors went off after it was
lit for a couple of seconds. I had to redesign.

I guess you could say copper is a great heat sink and it takes a lot
of heat to solder a big piece.

Carol


#16
    Hi everyone, I am new here and I am having a HUGE problem.  I
am trying to make a copp er lantern and cannot solder it!  I know
that this is a jewelry site but I figure that you guys would know
how to solder the copper.  I have made copper jewelry before and
have not had this problem.  I cannot get the solder to stick for
some reason. I have sanded the copper and put on a little flux and
it just won't work! 

what kind of solder are you using? Silver solder?? If the lantern
is all copper, I would suggest you go down to Radio Shack or some
such and get some of the solder that the electronics people use; the
"hollow core" sort that has the flux (rosin, I think) in the middle.
(NOT acid core!) I don’t think silver (borax type) flux would work
with this solder. The copper needs to be cleaned thoroughly, as it
usually comes with a somewhat greasy layer on it, and usually some
oxide too. You might also try “tinning” the joints before you solder
them. Margaret


#17

Hi Mindy, Let’s start with the obvious – what kind of copper are you
using? Are you sure it’s “real” copper, as opposed to some of the
copper-ish stuff they sell in craft stores that isn’t really the kind
of copper we (jewelers) use? For large pieces, I’ve even used copper
flashing as sold for gutters and roofs, which is roughly 24 gauge
(sold as “16-pound”), and had no problem soldering it. But I’ve
gotten copper wire and copper sheet pieces from craft stores that
either catch fire when heated (yuck!) or turn black and won’t solder
– both probably due to some weird alloy and/or coating used to
prevent tarnishing and patinas.

If you have “good” copper and still have the problem, try sanding
it, then pickling it and scrubbing with a brash brush until you don’t
see any beading of water on the surface (looks like when you get your
car freshly waxed) . Once you have eliminated water beading on the
surface, then don’t touch the surface to be soldered with fingers
(oil) or anything other than tweezers, flux it, and solder it. That
should help. It’s possible that there is some residual oil or
surface treatment that you can’t see, but that is preventing solder
flow.

Good luck!
Karen Goeller
@Karen_Goeller


#18

A number of my students enjoy working with copper and, as a result,
we have had to face the soldering problem. I find the following
works quite well.

Be sure to clean the copper well before beginning the processe…use
steel wool or fine sandpaper. Do all the same processes you would when
soldering silver…alcohol the piece, Prip’s flux all surfaces, set
the joins as perfectly as you can, use a good silver solder flux (we
still use Battern’s) or you can use a brazing flux if you wish, and
use clean silver solder snippets. Be sure to HEAT THE ENTIRE PIECE
just like soldering silver, then concentrate your heat on the
join…bring a small area up to red heat and the solder will
flow…reheat the entire piece and then move to another section. Do
not try to solder the entire join at once. We are using acetylene
and air with medium to large tips and have had no problems at all.
One student did a large angel candle holder and everything soldered
perfectly. Others have done silver on copper bracelets…again, no
problem Be patient…it takes some time to get the copper to
soldering temp. We also use exactly the same procedures with
soldering silver/brass, etc with no problems.

I believe one problem may be that copper oxidises quickly when you
put the torch on it. The Prip’s helps preclude this and keeps the
copper or brass cleaner longer allowing you to get to heat and get a
solder flow. Any metalurgists out there on this one?

Good luck and cheers from Don at The Charles Belle Studio in SOFL
where simple elegance IS fine jewelry! @coralnut1


#19

I have soldered copper and red brass. You need to get those metals
very hot and it is best to use more than one torch. I have soldered
fine silver to copper. Using a black flux on the body (Stay-Silv
black flux) which is used when extended heating time is needed and
white paste flux-- Handy flux–on the solder seam. I used IT solder
(little higher melting point than hard solder) because I was
enameling the piece, but you could most likely use the regular silver
solder.

You will need at least two torches to get the metal hot enough
(maybe even three). Play both torches all over to heat up the overall
piece and when it gets up to the correct temp and the solder begins
to flow, play the one torch on the solder seam drawing it along while
playing the other on the overall piece to keep it hot. Work fast
because your flux will break down if you don’t. Always nice to have
someone to help with the second torch, if you can find someone.

I have an oxy/acetylene torch with a Y attachment on the acetylene.
(go to your welding supply to buy that) My second torch is the
regular one that does not use oxygen but draws from the air-- but 2
acetylene torches might also do the trick. Louise
@lgillin1


#20

Soldering copper can be difficult, both because it is such an
efficient conductor of heat and because copper oxidizes very
rapidly. The former property makes it necessary to use a large
flame, and the latter makes it necessary to use adequate quantities
of a heavy duty flux. It is not impossible to solder copper–
plumbers do it all the time. Try using the same flux that plumbers
use- it is a paste flux called “Stay-Silv,” and you should be able
to get it at a welding supply shop.

Even using Stay-Silv, you are running a race, trying to get the
piece up to temperature before the flux loads up with copper oxides.
So,make sure the piece is completely free of oxides, flux that
piece up with Stay-Silv, use a large flame, and heat it up pronto.

Question- how big is the lantern, and what are you using for a
torch? You need to heat the whole piece up, as you would if you were
working with silver. If this proves impossible with your current
set-up, you may need to soft-solder it, using electricians solder as
Margaret suggests, or using the same solder that plumbers use.

Lee Einer