how different is brazing from sweeting in copper pipes?


Old 08-24-11, 12:51 PM
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how different is brazing from sweeting in copper pipes?

i read the local code and i need to braze the supply line that is buried from the meter to my house. i have sweated copper many times but never brazed copper pipes. from my understanding, it just solder that has a higher silver percentage so the temperature must be elevated in order for the solder to melt, which in turn gives you a stronger joint. am i correct? is this really different form sweating tin solder? any tips or do's or don'ts? i am going to practice a bit before i do it on the pipe i am installing but i want to make sure i am doing things right and what tips before i begin.
thank you,
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Old 08-24-11, 05:40 PM
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Brazing (using a brass filler rod) of copper tubing is somewhat difficult. Hard soldering, often called silver soldering, is considerably easier than brazing and only slightly more difficult than soft soldering.

Hard solder may, or may not, contain a small percentage of silver in the alloy whereas true silver solder will have a high percentage of silver.

The most important thing to remember when hard soldering is to have the pieces perfectly clean and well fluxed with the proper flux for the soldering alloy and the base metal. You need a higher temperature than for soft solder and most propane torches won't cut it. You need either MAPP gas or an air/acetylene torch.
Old 08-24-11, 06:14 PM
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In laymans terms

Soldering fills the void inside between the pipe and fitting.

Brazing seals the gap outside the fitting and the pipe. (Like welding)

Both seal the pipe.

Brazing is often used for A/C line sets.

Not sure where you live but We never brazed copper water lines for under ground.

Flare fittings are often used. Ford fittings are commonly used which are of comppresion type. The water company even uses a high end shark bite fitting now.

Mike NJ
Old 08-24-11, 06:25 PM
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The material you would need to braze copper tubing is either sil-foss or silver solder.

The term "silver solder" is commonly used to refer to silver brazing.
Silver solder uses a high temperature and should not be confused with soft solder that has a small silver content.
Sil-foss is a common refrigeration tubing brazing material and is easier to use than silver brazing in that you do not need any type of flux.

The difficult part comes with being able to diy because it takes more heat than you can deliver with a small propane torch.
You need an acetylene torch to braze and might have to call someone to help with this unless you want to try to rent one.
Also, if you wanted to do this yourself you would need to practice......... it's not rocket science but takes a certain knack to get it right.
Old 08-25-11, 10:05 AM
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thanks all. i now see there is a bit more to it than i originally thought. I live out in Long Beach CA and its the code here, i am guessing due to earthquakes but that is just my guess. i think i may just hire someone to run this so i know its done properly.

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