Brazing Alloys

[Stan]

There have been recent threads concerning zinc in boiler construction and the proper brazing rod to use. For anyone interested, there is a chart on Wiki listing every conceivable brazing rod with technical information, alloy, uses, trade names, generic name, etc.

Go to section 5 for the rod data and at the bottom of the page there is a lot of additional information.

http://en.wikipedia.org/wiki/Brazing#Brazing_alloys

 

[Lakc]

Thanks Stan, that looks to be one of the better examples of a Wiki entry.

It does leave me with one big question. Everyone appears to have their own favorite alloy when it comes to silver soldering (brazing). Aside from availability, worked in the past, etc. is there any law, spec, rule of thumb, etc. for the allowable alloys for boiler building? Is there some maximum zinc % allowable?

 

[Stan]

I don't make steam boilers so can't help you, but here is a quote from a previous thread. Maybe Jason will expand on this.

Re: is brass brazing rod a good thing to use on copper
« Reply #1 on: August 04, 2010, 11:24:14 AM »
Reply with quoteQuote
I would avoid brass or anything containing zinc as it can be leached out by the steam and weaken the joint material. Same reason to use bronze for boiler bushes not brass.

Jason

 

[Dan Rowe]

Stan, Very handy refference many thanks. The names of the alloys seam to favor US based information. There is no ISO, AS-Australian Standard, BS-British Standard, DIN-German Standard, or several other country standards.

For Boiler work Kozo recomends BAg-1 which contains both zinc and cadmiun.

I have a bit more to say about boiler silver solder alloys so I will start a thread in the boiler section.
http://www.homemodelenginemachinist.com/index.php?topic=10169.msg112553

Dan

 

[lastpatriot]

For what it's worth, I've used silver solder with 40% silver (coil not the flat sticks which have less silver) for various things it has really impressed me as to how Strong it is on one application it broke the base metal while the joint held.
but you need a close fit, it doesn't fill like brazing rod but is much stronger and it sweats into tight areas nicely.
It has cadmium in it. I think I payed $12 for an ounce of it, but that was probably 15 years ago.

 

[Kermit]

I've seen lots of bit and pieces of info and tons of links to other places for more information but I haven't seen any charts or pictures with an overall list of types of brazing alloys yet.

So without any more typing I present a pictures worth of words.