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Best solder for brazing copper to brass


#1

Besides silver, what is the best type of solder for brazing together
brass and copper that would be a good color match?

Are there other considerations I need to know about? Melting
temperatures? I also read something about how pickling turns brass
coppery and that a combo of hydrogen peroxide and pickle needs to be
used. I use citric acid pickle. How does that fit into all of this?

I had thought about using Metalliferous patterned brass sheet. One
archive post mentioned that their brass melted during sweat
soldering. Has anyone else had this experience with Metalliferous
brass?

Thanks for your help.
Lynn White


#2
Besides silver, what is the best type of solder for brazing
together brass and copper that would be a good color match? 

There are not any real good alternatives. There are some yellowish
silver based solders that have been sold as brass solders but still
not the best color match. The copper phosphorous solders are too hot
and will not flow the way one would want for jewelry type work, they
are more useful for plumbing. Your best bet is very clean, tight
joints with minimal solder use.

Are there other considerations I need to know about? Melting
temperatures? 

The big thing to remember is that silver solder is basically silver
mixed with brass (copper and zinc) so it is very easy to overheat
and make a real mess. So I tend to use lower melting point silver
solders which are also more yellowish in tone.

I also read something about how pickling turns brass coppery and
that a combo of hydrogen peroxide and pickle needs to be used. I use
citric acid pickle. How does that fit into all of this? 

Citric will work to activate the hydrogen peroxide just fine, it is
what I use when I need to do this.

I had thought about using Metalliferous patterned brass sheet. One
archive post mentioned that their brass melted during sweat
soldering. Has anyone else had this experience with Metalliferous
brass? 

This is true of any brass not just the patterned sheet from
Metalliferous. The higher the zinc content the more of a problem
this is. Your best protection is to work, clean and fast.

Jim

James Binnion
James Binnion Metal Arts


#3
Besides silver, what is the best type of solder for brazing
together brass and copper that would be a good color match? 

I’ve used Johnson Matthey “Mattibraze 34” to solder brass; it gives
a very good colour match, much better than normal silver solder. MP
is 610-670C (1130-1238F) and it contains Cd.

Regards, Gary Wooding


#4

here is a fairly good color chart:

http://tinyurl.com/yk6ahq

For brass color BAg-2 matches pretty well. The phos coppers tend to
gray they are self fluxing and hard.

For copper the best color match is gilding metal 95 copper 5 zinc.
this is the alloy in pre 1982 us one cent pieces.

jesse


#5
Are there other considerations I need to know about? Melting
temperatures? I also read something about how pickling turns brass
coppery and that a combo of hydrogen peroxide and pickle needs to
be used. I use citric acid pickle. How does that fit into all of
this? 

Lynn, go back through the Orchid Archives for several discussions on
solders for brass and for copper.

As far as I know, there is no truly copper-colored solder (cf.
earlier discussions on pre-1980 pennies). The best brass-colored
solder I find to be pieces of hammered and cut-up brazing rod (the
1/16" diameter one which is most available around here is Lincoln Low
Fuming Bronze [sic] bare welding wire; it comes in ca. 3-ft. lengths.

This only works with red brass; the brass with a higher zinc content
melts before the brazing rod will.

Pickling does not turn brass coppery; heating oxidizes brass and
turns it black and also red. Pickle will remove the black but not the
red. The combo of H2O2 and pickle will remove the red.

Have fun!
Judy Bjorkman, Owego, NY


#6
Johnson Matthey "Mattibraze 34" to solder brass 

Gary, do you know pf a place online, to buy “mattibraze 34”?
thanks,

Andy


#7

Hi Andy,

do you know pf a place online, to buy "mattibraze 34"? 

First off, I’m in UK, so this might not be of any use to you. I got
a couple of sticks from a small company on the Bayton Road Ind Estate
in North Coventry. I found it by accident when I just happened to
pass by on my way to somewhere else, and I’m afraid I’ve forgotten
it’s name. I contacted Johnson Matthey Head Office who gave me the
following stockist address, but I could find nothing online. Sorry.

All Welding Supplies (Walsall) Ltd.
Unit 7 Safe Harbour Industrial
Estate
Birmingham
B6 7AE
West Midlands

Tel: 0121 3564505

Regards,
Gary Wooding


#8

http://tinyurl.com/yk6ahq

For brass color BAg-2 matches pretty well.

Mattibraze 34 WAS a cadmium bearing silver braze alloy sold by
Johnson Matthey.

Mattibraze 34 contained 34 silver, 25 copper, 20 zinc , 21 cadmium

They also once made Mattibraze 35 that contained 35 silver, 26
copper, 21 zinc, 18 cadmium.

I am familiar with that one-- I can see no signifigant difference–
there is no magic here!

They have discontinued all cadmium bearing materials !

The cadmium contining brazes seem to be still available here in the
US but I stopped buying them in the 70’s !

jesse


#9

Hi Judy, you seem to have some good experience brazing brass. I am a metal railings fabricator, not a jeweler, and am looking for insight on how to braze a brass railing together. The railing is unusual in that I must braze solid bar to hollow tubing(heavy wall), and I have many hundred of connections to make. I’m looking into an induction coil, which can rapidly heat the bronze to cherry red in about 30 seconds. My thought was to bring up the temp, then flow in a rod. The endgame is for the rod color to match the brass.
Your thoughts?


#10

Hi Gam,
im somewhat surprised that you havnt had any recent replies to your questions here on this forum.
so i thought Id chip in with some thoughts that might help you.
Thinking about the railings youve been ,I presume asked to quote for, does that involve fixing as well as making?
If so you really need to get involved in the project as a lot of architects designers arnt very practical. are the railings inside or outside the building?
who is responsible for the design? ie safety? . My guess is that your very experienced in steel and s/steel railing work and this is a step outside of your normal work.
I had a request for something similar some yrs ago and it fell down because the technical specs just didnt add up and I walked away from what would have been a real can of worms.
can you detail the dimensions in imperial the rail section and the tube size ie int and ext size and wall thickness and brass spec inc melting temp? most important!, as that will really determine how you will braze the tube to the underside of the rail.
induction heating sounds an easy way out to heat BUT one will have a mass much larger than the other. also you will need to do the brazing with it jigged like an upside down “T”. it wont be structurally sound the other way.
also an induction coil will have to fit the “T” some how so that when the joint is made you can get it off the work!
You will also need to use a flux, the brazing alloy will not flow without it. also the designers request? for the same colour? yes that possible but its underneath the rail so it wont be seen.
the same colour rods melt a too near the melting point of the brass!. You need at least a 200 D Cent. difference.
Brazing joints need to fit to within a few thou as the brazing alloy flows by capilliary action .
One final thought for the moment, I would ask the brass rail and tube suppliers for several feet as samples. then take them to the induction heating kit supplier and ask them to show you how to do it! If they cant provide a consistent result the walk
away from this quote.
Reply with the metal sizes and ill see if i can come up with another way of doing this.
Ted, bronzesmith and minter.
Dorset UK


#11

Hun=mmm!!! I do bronze sculpture and have in the past done custom railings in bronze/brass, steel and aluminum. I would think you would want to weld these fittings not solder or braze them. I do not see or at least understand why one would solder such units verses TIG weld them (you could gas weld the even MIG weld them but the TIG will give the best looking and strongest connections, at least in my opinion……. If I can be of any help, I would be glad to discuss any thoughts, ideas or problems with you or others…

John Dach


#12

Gam, the first thing is to find out what the melting point of your railing brass is. If it is made of the alloy which contains a little lead and/or more zinc,it probably will melt before the brazing rod will flow. The idea of an induction coil sounds good (I am not familiar with those things), because the metal will have to be very hot before the brazing rod will flow. And of course anything of any size will be radiating heat like crazy. I hope your brass railing pieces are smallish. If all of the preceding works out, you might also try brushing some high-temperature (black) flux on the joins, to keep down the oxidation of the metal while it’s heating up to the temperature which will melt the brazing rod. As for color, the type of brazing rod I mentioned in my preceding (July 13) communication is a very decent match for most (gold-colored) brasses. I use it for the seams of heavy brass finger-rings, and once it’s been pickled, bright-dipped and polished, the seam is really not visible.
In terms of preserving heat, as you are heating the connection, is each one shaped so you can surround it with soft firebrick (pieces), so as to form a little temporary “furnace?” Do not place the metal on a big solid firebrick — those things are heat sinks.
If you have any other questions/comments, don’t hesitate to write!
I wish you all the brazing best!
Judy Bjorkman


#13

Can you tell me more about the pickel and brite dip? What products do i
use, and how do i use them?


#14

Gam, as mentioned in one of my old replies, the heat of brazing will cause the brass to turn black and also red (the colors of the copper oxides produced by the heat; copper itself is also produced,as the zinc in the alloy starts to fume off). Pickling will remove the black. The pickle I use is sodium bisulfate, found most cheaply at pool supply stores and called “PhMinus.” Dissolve some in water, in a container of handy size, and let the brazed piece sit for awhile in this solution. Rinse in water,wipe off any black remaining.

As for the red oxide, I use dilute nitric acid (50:50) for bright-dipping, which is quick and great for brass jewelry but obviously can be dangerous. (I have been using this system for 40 years without incident,but I don’t allow anyone in this part of my work area unaccompanied.) A much safer and somewhat slower method for bright-dipping is to use a solution of PhMinus and hydrogen peroxide (available in drug stores). Dissolve the PhMinus in water and then add the peroxide. I cannot give you measurements on this because I haven’t used this system for years. Someone else may be able to better define this for you. The test is: does the red come off the brass after several minutes of soaking? (BTW, gentle heating improves the speed of both pickling and bright dipping.) If it does,try polishing your piece with 4/0 steel wool, for a nice bright look. To prevent the slow, natural oxidation of brass, as time goes on, waxing may help, if this is an indoor railing. I’ll let others offer you advice on that!

It may be that your best solution is to do the TIG welding, as John4 has suggested. But I am not familiar with that process. The questions and suggestions which Ted from the UK has raised are also very good.

All the best, Judy Bjorkman


#15

Judy:

As usual, your reply is chock full of useful information. I will try out
all of your recomendations.

Regarding TIG welding, in fact, it is something that my shop does all day,
every day. However, it’s not suitable for this particular project, because
it requires a tremendous amout of time to grind smooth, & polish the welds.
Whereas, over the years, I have seen soldering, & brazing work, which
required no secondary finishing.

I will try your suggestions, and let you know how it’s going. It won’t be
for another few weeks, because I’m still working on extruding the bronze
profiles.

Any chance you might want to take a trip down to sunny New Jersey, and give
my lead fabricators a seminar?

Take a look at my website www.arcmet.com to see what we do.

Thank you for all of your help.

Please visit our website www.arcmet.com to see the excellent custom
metal & glass projects we’ve design/built during the last 21 years.

Gam Kagan
President & Founder
Architectural Metal Fabricators Inc.
66 Grant Ave.
Carteret, N.J. 07008

Cellphone: 347-875-6426
Cellphone: 718-877-8909
Office 732-352-0763 X202
Try me at either # If no answer, please leave voicemail
I check for voicemail’s frequently


#16

I braze/solder brass all the time and also TIG weld regularly. A properly
done TIG joint should be less work to clean up than a brazed joint in this
application plus you will get a better color match. A good TIG welder
should be able to make you a joint that requires almost no grinding.

The only caveat is that not all brass alloys are weldable. If the zinc or
lead content is too high, it just makes a mess.

Jason


#17

Hi Gam,
Just out of interest, Ive thought your problem a bit more, i do engineering consultancy, so trouble shooting is what im good at!.

  1. Id set up the railing underside up in a supporting jig in a mill,
  2. Id use a core drill to cut a groove say 1/4in deep where the upright tube have to go the size to match the tube dimensions.
  3. Then you use brazing paste, this comes already with flux, ( use it all the time here)in the bottom of the groove place the tube uprights in the groove, and heat.
  4. How you do this as you have mentioned can be induction but need to put this to the induction heating kit supplier to advise. or id prefer 2 rose buds running oxy and propylene gas is cheap in the US. have this set up in a ceramic brick muffle which will retain the heat
  5. one operative pushing the railing through in the jig , another checking the joint.
    This way you will not see any surplus brazing alloy and a much stronger joint than a plain but braze.
  6. Pickling is an issue,
    The way we do it here is we use on all non ferrous meals, dilute h2s04 which is in a large container to suit the work. The key is you put the work HOT as from the brazing right into the acid. comes out bright.
    As to bright dip, ive the uk formula, dangerous stuff and wouldnt be practical for your railing job.
  7. happy to come to set it all up for you.
    all we would argue about is that cost.
    Ted.

#18

Gam, I glad if my information is of use to you, and I look forward to hearing how the project goes, when you get started. If you have any further questions, send them on.

I think that the project’s success may depend on the size of the pieces you want to braze (small, and comparable sizes = better situation)

I looked at your website, and your work is very impressive! As for giving a “seminar,” I don’t think I know that much, beyond a little workshop on making a brass ring with a bezel (to set a stone), using hammered pieces of brazing rod as the solder. One of the other ways I like to use brazing rods is to just flow it onto copper or nickel-silver in random, abstract patterns. But your work is much more exacting.

Ah — metals are such fun!

All the best,
Judy Bjorkman,
Owego, NY