Brass Soldering?

skyjive · Sat Jun 13, 2009 9:30 pm

Hi all,

Is it possible to form a secure solder joint between normal copper pipe and the brass tubes found here?

http://www.mcmaster.com/#telescoping-tubing/=2b10c0

Or more generally, can you solder brass and copper together?

ralphd · Sat Jun 13, 2009 9:56 pm

Sure, I do it all the time, I'm in the HVAC industry and I sometimes have to "MacGyver" pieces to get jobs done. You have to use silver solder and flux. The higher the silver content the better in my opinion.

pharmboy · Sat Jun 13, 2009 9:57 pm

Yes, as brass is mostly copper, the two can be soldered together easily. I'll have pics of just that when I post up my next project. The same can be said for bronze, just like the bodies of most sweat-together ball valves.

skyjive · Sat Jun 13, 2009 10:23 pm

ok thanks for the quick responses I appreciate it

pharmboy · Sat Jun 13, 2009 10:45 pm

Forgot to mention the silver solder, nice catch, Ralph. Although, I think it's darn near impossible to find good-old lead solder anymore. That stuff would flow like nothing else. I just put together a copper cannon today, and getting the lead-free stuff to flow was a definite pain.

Gippeto · Sat Jun 13, 2009 11:47 pm

You don't have to use "silver solder" to join brass and copper. I use 95/5 Tin / Antimony.

It actually results in a stronger piece than one that is silver soldered, as the temperature required for silver soldering is high enough to anneal the copper.

Not a problem in HVAC where most of the copper you're working with is already in an annealed condition. But not the best choice for maintaining the working properties of drawn copper.

Technician1002 · Sat Jun 13, 2009 11:53 pm

pharmboy wrote:Forgot to mention the silver solder, nice catch, Ralph. Although, I think it's darn near impossible to find good-old lead solder anymore. That stuff would flow like nothing else. I just put together a copper cannon today, and getting the lead-free stuff to flow was a definite pain.

There are two kinds of silver solder.. Take note.

The silver solder on a roll requires flux. The silver brazing solder for rigid HVAC installations is a very stiff stick. Do not use flux with that stuff. It requires a oxy accetelene torch. Unless trained, don't attempt to use the other stuff. It requires the use of a carborizing flame to flux the copper. I still have a 1/2 lb of the stuff from a 16 ton AC install. A simple air propane torch won't get it to flow as it won't properly flux the copper.

For strength, the hard solder can't be beat. Copper pipe will rip beofre the joint lets go. You can tell the hard brazing solder in HVAC stuff as it is brownish in color instead of silver looking on the pipe. Before use it is silver in color.

pharmboy · Sat Jun 13, 2009 11:58 pm

Quick thoughts...am I right here, as far as anything that's not potable water supply piping, lead-free solder sucks, no?

Technician1002 · Sun Jun 14, 2009 12:07 am

pharmboy wrote:Quick thoughts...am I right here, as far as anything that's not potable water supply piping, lead-free solder sucks, no?

Silver brazing solder rocks, if you have the equipment to use it. It is lead free. It runs like water when molten and sucks right into small spaces better than regular solder. It's hard a brass when cold.

This page has info on silver brazing. In the table, it lists copper a self fluxing but Brass needs flux. I haven't done brass so this I didn't know.

http://silfos.com/htmdocs/product_suppo ... guide.html

I love the 15% Sil-Fos

Brass Soldering?

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