Original message
| stiz
 |  "brazing a/c joints ????"
, posted Fri 4 Jan 16:35  
I have been wondering about the topic of brazing a/c line set joints. From what I hear from different installers there is a variety of opinions on which solder and method is best. Also doing a low flow nitrogen purge while brazing seems to trigger a lot of discussion from hvac tech's. Some will say use 45% silver rod with flux, some will say use 5% without flux, and some talk of a rod made by Harris that is the best to use. Also the source of heat for brazing seems to bring about a variety of opinions. Some will use acetylene/oxygen others acetylene/air, and others map gas. Given the talent and experience that is available on this forum, could we have some posts on the subject and possibly settle this once and for all. So the question is: what is the proper procedure or best procedure to follow when making copper to copper connections in an central a/c install. thanks, stiz
from charlie
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Replies:
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| cliff smith
| "Re(1):brazing a/c joints ????" , posted Sat 23 Feb 14:09
brazing u are right their are a lot of different ways to get same job done i will braze any thing from 3 1/2 to 1/4 " with a turbo torch the differance is in the size tank u use , for acr pipe i use 15%cadimum silflos on ever thing an always leave a nice little curb on joints this way the visual leak checkis good for 400 psig leak ckeck over heat is a problem for beginners but call backs or leak check an entire wearhouse system at a beer per leak will correct that problem , when joining copper to carbon steel or any other , i will tin the pices with silver and then cap with silflos for strength dont seem to have many issues and pressure and vacume test is very ridgid in oil ang gas industry
thecoolguy
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| Jojo98
| "Re(1):brazing a/c joints ????" , posted Tue 29 Jan 23:00
The proper proceedure is, NO Leaks, No Leaks, NO LEAKS!!!
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| Freezone12
| "Re(1):brazing a/c joints ????" , posted Wed 9 Jan 18:49
I prefer to use oxy/acy when brazing copper joints. I have used a turbo-torch in the past but find the noise they create annoying, and the flame is not as hot as an OA rig. OA is a much faster weld, but turbo-torches are more portable.
if I'm repairing a leak on a 1/4" to 3/4" line, my mapp torch does the job just fine. it weighs less on some of those hikes necessary to get to the job.
I have all three types of torches on my truck, and the one I use depends on the job I'm doing.
45% silver solder on copper/copper joints is a waste. I save that for dissimilar metals, ie, copper to brass, etc. I use a 15% silv-phos rod. it flows very well and takes slightly less heat to form a good joint than say 0-5%.
flowing nitrogen is necessary unless you are using suction and liquid line filter/driers with replaceable cores. personally I run the gas anyways, but I know people that don't. they change out the filters, but they also have dark oil in the compressors which I don't like.
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If it don't fit
force it.
If it breaks
it needed to be replaced anyways.
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