Jump to content


Photo

How to braze or weld silicon bronze???


  • Please log in to reply
20 replies to this topic

#1 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 04 October 2009 - 02:58 PM

I'm Making a sculpture, a bird, like this one: http://www.metalarti...ad.php?tid=4596, except much larger and, for the first time, I'm using 1/16" silicon bronze (alloy 655). I have never made anything out of bronze before. I'm wondering what to do when I get to joining the seam. My expertise is in silver-soldering, and I have very little experience with brazing, using that brass-colored brazing rod from the welding supply store, and when I have, I was not very happy with the results. As a matter of fact, my supply of brazing rod was purchased over 30 years ago, and I still have most of it left. The bronze is a light copper color, so I'm thinking silver solder might show up quite a bit. The brazing rod I have is yellow, like brass, so I think that wouldn't be any better than silver solder. Everything I've read about silicon bronze says it can be easily welded by any method. The problem is, it's a butt joint, which is the most difficult, IMO, and with my lack of experience, I can see me melting a hole in it and ending up with ten hours of work being scrapped. What are my options? Is there brazing rod available that would match the color of the bronze? BTW, I have to use a torch; I don't have MIG or TIG or any of that fancy stuff. Any guidance would be appreciated. [Beer]

#2 Tony Mertens

Tony Mertens

    Metal Master

  • Subscriber!
  • PipPipPipPipPipPip
  • 2,298 posts
  • LocationNew Holstein, WI

Posted 04 October 2009 - 03:10 PM

Talk to your local welding supply house. I know you can get silicone bronze TIG rods so they should have them for the torch. I'm not too familiar with O/A welding - they may even be the same rod for either process.

#3 PTsideshow

PTsideshow

  • Moderators
  • 8,479 posts
  • LocationMount Clemens,Mi

Posted 04 October 2009 - 03:39 PM

How close is it to copper in color, As Harris 0 is a good match to copper sheet. Tractor supply sells Harris 0 gas rod, in smaller packages.You may not like buying 3 to 5 pounds. A lot of the gas rod can be used for TIG or the other way around.
Looking in the Crown Alloys rod and wire book
They have a Crown Silicon Bronze rod that can be used for TIG and Torch
The instructions for torch are dip heated rod into Tiger Flux3 and proceed to finish flowing alloy into joint until it is completed.

The rod melts at 1866'F

Royal Tiger Flux #3 is General purpose brazing flux Temp range 1550'F to 2000'F


Looking in the Airgas catalog They have Randor Silicon Bronze 36" lengths,1/16" 3/32" in one pound packages. Used for joining copper alloys.
I'm sure that Praxair has the same type.
[Beer]
glen

moderator

Posted Image

"I am not ashamed to admit, that I am ignorant of the things I do not know"!

Cicero

I am not a lawyer, and never played one on TV!

All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or suggested uses, Wear safety glasses, closed course, professionals only

#4 Vermontsmith

Vermontsmith

    artist blacksmith

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 392 posts

Posted 04 October 2009 - 04:57 PM

Like Tony said, since you know the alloy of the base material look around for a matching filler rod of the same alloy. Ask your local welding supply place to order some in if needed. "Tig" filler rod can be used if you get it hot and dip it in a can of brazing flux prior to A/O torch brazing.

-Judson

#5 johnwalkeasy

johnwalkeasy

    Skilled Metalsmith

  • Members
  • PipPipPipPip
  • 73 posts

Posted 04 October 2009 - 05:32 PM

I've use a lot of silicon bronze welding rods over the last 30 years. I'd never used them with a tourch. So I can,t answer to that issue. I,ve always use a Carbon arc rod. Useing S.P. on a DC welder. You can weld steel and stainless steel. And with a tig. welder you can weld copper. I,ll try to post a picture of something I,ve made useing this process. A procress I call Steel & Bronze. 
Biker 69, Steel & Bronze, 32" long. 2005.

Attached Thumbnails

  • Picture 10159.jpg


#6 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 04 October 2009 - 06:59 PM

Thanks, all for your answers. It looks like everything you're suggesting is for WELDING rather than BRAZING. Is welding my only choice other than silver-soldering (silver brazing)?

#7 PTsideshow

PTsideshow

  • Moderators
  • 8,479 posts
  • LocationMount Clemens,Mi

Posted 04 October 2009 - 07:36 PM

No you can use the TIG rod with an oxyacetylene torch and brazing flux as In my first post and in Judsons post after mine. You will have to prefect your technique on some test pieces and for color match tests.
The brazing flux in my post is the same as most other good quality fluxes.
I just typed the instructions from the filler rod catalog.Tech sheet downloads for the silicon bronze alloy filler rods scroll down the page to copper based alloys 6th one down is the filler rod.
The Harris 0 filler rod is a closer match to copper color.
[Beer]
glen

moderator

Posted Image

"I am not ashamed to admit, that I am ignorant of the things I do not know"!

Cicero

I am not a lawyer, and never played one on TV!

All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or suggested uses, Wear safety glasses, closed course, professionals only

#8 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 04 October 2009 - 08:01 PM

Glen, thanks again.
I looked at the alloy for silicon bronze at the link you provided. its melting point is 1866F, which is about the same as the silicon bronze I'm using for my sculpture, which is 1780-1880F. The distinction between welding and brazing, as I understand it, is with welding, you are actually melting the metal you are joining, and adding filler as necessary, and with brazing you are not melting the metal you are joining, but melting only the brazing alloy so that it flows into the joint and bonds the two pieces of metal together. So what you are talking about is welding, not brazing. I think I would want to get a lot of practice at it before trying it on a sculpture I have several hours invested in.

#9 PTsideshow

PTsideshow

  • Moderators
  • 8,479 posts
  • LocationMount Clemens,Mi

Posted 04 October 2009 - 08:18 PM

Check orchid message archive in the last 3 or 4 weeks there were a number of messages on somebody finding a brass match color soft solder. Don't remember, but there were a number of messages and answers
[Beer]
glen

moderator

Posted Image

"I am not ashamed to admit, that I am ignorant of the things I do not know"!

Cicero

I am not a lawyer, and never played one on TV!

All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or suggested uses, Wear safety glasses, closed course, professionals only

#10 warrent

warrent

    Torch Lighter

  • Members
  • PipPipPipPipPipPip
  • 1,329 posts
  • LocationTrenton, MI

Posted 04 October 2009 - 09:02 PM

Steve,
This is what I do, I cut some very thin strips of the alloy I am using. Then you are actually welding with the strips because you melt the strips into the base metal. Get some regular brazing flux. Heat the strip and then dip in the powder. The flux is only there to help get a puddle flowing. Once you get the puddle flowing the strip will melt into the base metal and you will have a little weld bead. Yes I do this with the O/A torch. Practice to get your heats correctly. A smaller tip that is cranked up works the best because you will need a lot of heat but you want to concentrate as much as possible.
You can also try regular low fuming bronze brazing rod, but you again have to melt into the base metal. I find though that you still get a little yellow.

Here is somthing that I am working on that is a bronze, not sure of the alloy so this is how I approached.

bronze welding.jpg
Warren Townsend
http://www.metalrecipes.com

Metal recipe - "heat and beat to the desired shape, repeat as necessary"
If you're gonna be original, you can count on being copied.

#11 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 05 October 2009 - 06:00 AM

Glen, I just read your first reply more carefully, and after doing a little digging on the site that I get my silver solder from, I think you may have given me the answer I needed right off the bat. Harris 0. It's lliquidus temp is 1475F, well below the melting point of my bronze, and the price is right.
Thanks. [Beer]

#12 PTsideshow

PTsideshow

  • Moderators
  • 8,479 posts
  • LocationMount Clemens,Mi

Posted 05 October 2009 - 06:23 AM

I would make sure that the Harris 0 is a color match as it is close to copper in coloring or shade. It may be to red for your bronze sheet. Is the bronze sheet one of those new jewelry art metals along the lines of the new gold, NUgold etc Brass or bronzes yet not brassy looking.

Warren had a great idea about using the sliver of the material for filler rod, and the brazing flux as a flow agent.as the color should be right on as it would be like fusing the butt joint edges.
Even if the melting temp is higher the use of it as filler rod and flux will work.

It is the same as using an oxyacetylene torch to braze copper with electrical wire. Since the electrical wire copper is melted in an non oxygen environment/furnace. Like the oxygen free copper TIG rod.

Something to try as you are practicing and playing with some metal other than the already formed pieces.
[Beer]
glen

moderator

Posted Image

"I am not ashamed to admit, that I am ignorant of the things I do not know"!

Cicero

I am not a lawyer, and never played one on TV!

All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or suggested uses, Wear safety glasses, closed course, professionals only

#13 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 05 October 2009 - 06:39 AM

Glen, the material I'm using is high silicon bronze, the same stuff they use these days for casting large sculptures, only this is in sheet form. It looks much more like copper than brass, in fact it doesn't seem to have any yellow to it at all. The Harris 0 is cheap enough that I can experiment with it a little, and if it doesn't look right, I'm not out a lot of money. As for welding, that may be in the future, and I can see that it would expand my possibilities a lot, but I'm not ready for it on this project.

#14 Deafboy

Deafboy

    Metal Master

  • Members
  • PipPipPipPipPipPip
  • 1,485 posts

Posted 05 October 2009 - 06:41 AM

Steve,

I've been silver soldering silicon bronze for many years.
I use Harris Stay Silv 45. it's not the perfect color match
but it's close enough when I polish my work.
Look on ebay and buy a little bit to see if it will work for you
or I'll be happy to send you a sample. I have a ton of it...

Dan
Dan~ Posted Image

#15 warrent

warrent

    Torch Lighter

  • Members
  • PipPipPipPipPipPip
  • 1,329 posts
  • LocationTrenton, MI

Posted 05 October 2009 - 07:29 AM

Steve,
On the Harris 0, when you use it the original look will be a copper flash coating, once you sand it turns to a nickel color, more darker than solder. But what you have to watch out for is that it is brittle. It does not like any hammering at all and cracks. Furthermore when sanding it is harder than the copper or bronze.
The Silv 45 has more silver content and easier to flow and sand.
Warren Townsend
http://www.metalrecipes.com

Metal recipe - "heat and beat to the desired shape, repeat as necessary"
If you're gonna be original, you can count on being copied.

#16 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 08 October 2009 - 11:27 AM

Dan, Warren, for some reason the email notification didn't work and I was unaware that you had commented on this. What I use for my brass work is Harris Safety-silv 45, which I guess is like stay-silv 45, except it's cadmium-free. Unfortunately, I already brazed the bird sculpture with the Harris 0, and just as you said, Warren, it cracked when I did more hammering on the piece. I re-brazed it with 0 where it cracked, and if it cracks again, I'll re-braze with sf45. I'm really disappointed in the Harris 0. I saw there's also a stay-silv 15, which is 15% silver, and I would think might be copper-colored, but don't know. The online supplier I normally use only sells it by the pound, which makes it way too expensive for me.

#17 PTsideshow

PTsideshow

  • Moderators
  • 8,479 posts
  • LocationMount Clemens,Mi

Posted 08 October 2009 - 11:49 AM

Steve sorry, to hear about your troubles. Here are two links to silver solder and alloy suppliers the first is the be all and end all of information.

Brazing and soldering info

Here is Harris's site with their PDF downloadable info

[hysterical]
glen

moderator

Posted Image

"I am not ashamed to admit, that I am ignorant of the things I do not know"!

Cicero

I am not a lawyer, and never played one on TV!

All the usual and standard disclaimers apply. Do not try this at home, use only as directed, No warranties express or implied, for the intended use or suggested uses, Wear safety glasses, closed course, professionals only

#18 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 08 October 2009 - 02:37 PM

Thanks for the links, Glen.
I've pretty much decided that I'm going to practice welding and the next piece I make with the bronze I will weld.

#19 warrent

warrent

    Torch Lighter

  • Members
  • PipPipPipPipPipPip
  • 1,329 posts
  • LocationTrenton, MI

Posted 09 October 2009 - 07:48 AM

Steve, sorry to here that it did crack. With the Harris 0 it is great for assembly work and that is about it. I have redone so many welds that cracked from just simple bending. But price is okay for what I now use it for. Sometimes all of the links and info overwhelming and I believe in do it before you share it.
Warren Townsend
http://www.metalrecipes.com

Metal recipe - "heat and beat to the desired shape, repeat as necessary"
If you're gonna be original, you can count on being copied.

#20 Steve Shelby

Steve Shelby

    Metal Master

  • Metal Artist Forum Sponsor
  • PipPipPipPipPipPip
  • 383 posts

Posted 09 October 2009 - 02:52 PM

Thanks Warren. I now have a lifetime supply of Harris 0, since I can't think of much use for it. I ended up silver-soldering the joint, which worked very well.
I went to my welding supply today to exchange my acetylene tank, and got some silicon bronze rod for welding. Time to do some practice welding.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users