I need to do some work on one of my compressors, but the copper air line is preventing me from getting at the parts that I need to remove. I'm not sure if the lines are soldered or brazed. I don't know anything about brazing. Can I heat it up and remove it without damage like you can with a soldered joint, or is brazing more or less permanent? Ideally, I'd like to separate the joint with the green corrosion on it.
If it's a copper line, I'm going to GUESS it was soldered. Get out a smallish torch and heat the joint up. If the stuff starts flowing, it was solder. Brazing has to be really hot, relative to solder, which melts at like 900F or so, if I recall.
If its a compressor, its been soldered / brazed with a silver alloy solder (silfos or something similar). You can heat it up to get it apart, don't know if propane is hot enough (I use oxy acy for everything).
Might be problem getting it back together if you don't have the silfos rods. and remember, if you do have the rods & putting it back together - you'll need to run nitrogen thru the lines while solder / brazing.
KJ
It's copper and that is a silver solder joint. map gas could work.
I have Mapp gas so that shouldn't be an issue. Of more concern is the fact that it's covered in oil.
Hit it with the torch, Woody. It won't be covered in oil for long.
Could you cut it in a straight section and fix it with a compression union?
Kenny_McCormic wrote: Could you cut it in a straight section and fix it with a compression union?
Now there's a thought. I'll have to take a closer look and see if I can fit a small tubing cutter on one of the straight sections.
They usually use a silver-bearing filler - note pure silver.
I keep Harris 5, 15 and Safety-Silv 56 around as well as Stay-silv white flux and some brass filler rod and old school heat-dunk powdered flux.
It's more convenient to braze stuff than to TIG sometimes.
Edit: To un-braze, heat 'til it flows, and twist apart while still heating. Be careful - molten brass/silver spatters hurt.
All I know is Silbraze isn't cheap and you know if it is silverbraze because it takes a ton of heat vs. lead. I have a stash of silverbraze from my grandfather, it isn't the new non toxic formula either. If someone was able to put it together by brazing surely you shall be able to do it yourself. Brazing was probably the only thing I ever did good in the stick/oxy welding class I took oh so many years ago.
Silver solder is available at Home Depot. Works, but doesn't seem to be as good as the stuff I've gotten elsewhere.
If you clean before you torch, let it dry off first. Depending on what you clean with, you can get some nasty fumes.
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