Brazing line set

[do over]

I would like to see what people are using to do there line sets. I think it would be fun to see the see how different we are to do the same job.

I use the cheep green pads to clean the copper. They leave no residue.
Stay-sil 15% brazing rods.
Oxygen acetylene torch
#3 tip < 5/8”
#7 tip > 5/8”
Purge line with Argon (not nitrogen)
Thermal Engineering analog Vacuum Gauge.
Robinair 5 cfm Vacuum Pump.
Wet rags as heat shield.
Ratcheting Tube Bender you know the ones you need to keep repositioning on the larger tubing or you will kink the tubing.

[do over]

I learned the trade at Columbus technical collage back in 74-76. That was a long time ago, I remember the instructor telling us then that there was a new gas out called MAPP, he told us never to use MAPP gas because it didn’t have the heat needed to do the job right. Back then we were thought brazing using an air acetylene torch with a B tank. I can’t remember the name of it but it looked like a turbo torch. All I can think of is we cooked a lot of copper back then. This is my thought on MAPP gas because that what I learned. I also don’t think air acetylene witch I learned on is not a good choice for a torch anymore. But then maybe it's as I was told once, it's not the torch, it all in knowing how to use the torch.

[Tool-Slinger]

I prefer turbo torch, 15%, fiberglass cloth[the one with the little squares in it], and wet rags. -

[LowCashACR]

I learned the trade at Columbus technical collage back in 74-76. That was a long time ago, I remember the instructor telling us then that there was a new gas out called MAPP, he told us never to use MAPP gas because it didn’t have the heat needed to do the job right. Back then we were thought brazing using an air acetylene torch with a B tank. I can’t remember the name of it but it looked like a turbo torch. All I can think of is we cooked a lot of copper back then. This is my thought on MAPP gas because that what I learned. I also don’t think air acetylene witch I learned on is not a good choice for a torch anymore. But then maybe it's as I was told once, it's not the torch, it all in knowing how to use the torch.

the instructor i have now says mapp gas will work, but not propane. i haven't tried it yet, but have been using oxy-acetylene torches

[Boise500]

Do Over, you sound like a perfectionist, not a bad thing.

[busterweaver]

brazing with mapp gas is good for about 3\8, 1\2 inch max copper, if its close to any larger masses of metal, you gotta get out the oxy acetyl. it is convienent for repairing hairline condensor cracks on rooftops, just easier and lighter to carry.

[TCreacy]

Brazing is done at tempertaures around 1200-1800*F
Soldering is done around 500-800*F

Brazing Should always be used with refrigerant and anyother highpressure piping, it brings the copper to a hotter state and allows the filler material to bond with the molecules

Soldering is done a low temps and basically all you melt is the solder, and it will only adhere to the surface of the copper.

I cant find the exact temperatures online, but I havent know an Air-Acetylene rig or Air-Mapp rig to get hot enought to properly braze.

Now for a bonus question: What does the Acetylene B and MC tanks sizes actually mean. (Where did the lettering standard come from)

[Wheelbaron]

I use Oxy Acetylene for most jobs, but have my handy Turbo for back up, or jobs with a lot of joints. 15% wet rags, abrasive cloth.

Buddy of mine does all resi stuff, and always solders his line sets, been doing it for many years and never had a joint leak after initial test. Uses a hand MAAP torch, hard to argue with his results. And he has never burnt a valve or TEV.

I use Nitro like most, is Argon cheaper?

[Thurmont HVAC]

Now for a bonus question: What does the Acetylene B and MC tanks sizes actually mean. (Where did the lettering standard come from)

I was taught that the tank designation was from the old days, MC Meant for Motor cycle use, as in the Head light, yes bottled gas was used for lighting, and the B tank was for use for bus head lights. not sure if it is 100% correct, but thats what our instructors taught us in trade school in the 80's

[VTP99]

I was taught that the tank designation was from the old days, MC Meant for Motor cycle use, as in the Head light, yes bottled gas was used for lighting, and the B tank was for use for bus head lights. not sure if it is 100% correct, but thats what our instructors taught us in trade school in the 80's

Very interesting.

[TCreacy]

I was taught that the tank designation was from the old days, MC Meant for Motor cycle use, as in the Head light, yes bottled gas was used for lighting, and the B tank was for use for bus head lights. not sure if it is 100% correct, but thats what our instructors taught us in trade school in the 80's

MC = Motor Coach (cars)
B = Buses
Youre right on...

[neophytes serendipity]

MC= Motor Car

[midhvac]

What's pipe diameter limit for a straight acetylene turbo torch using 15%?

[VTP99]

What's pipe diameter limit for a straight acetylene turbo torch using 15%?

About 1" is my guesstimate.:rolleyes:

[do over]

I use Nitro like most, is Argon cheaper?

Argon cost more. 80CF of Argon is $40

[busterweaver]

I saw at the Dome Hepot and wowes stores they now have tiny oxy-mapp gas torch sets, just wondering if anybody else has seen this and comments. Didn't really notice what they were marketed towards.

[Tool-Slinger]

I saw at the Dome Hepot and wowes stores they now have tiny oxy-mapp gas torch sets, just wondering if anybody else has seen this and comments. Didn't really notice what they were marketed towards.
Jewlers use tiny rigs.

[busterweaver]

That makes sense.

[uniservice]

used to have a jewelers torch tip and handle that we used to braze or solder lead. Had refrigerated anodizing vats that were lead lined. Had to repair leaks in the liners, as the solutions used to anodize the aluminum would eat up the copper refer lines under the lead liner. welding lead is a fun thing to learn.

[VTP99]

used to have a jewelers torch tip and handle that we used to braze or solder lead. Had refrigerated anodizing vats that were lead lined. Had to repair leaks in the liners, as the solutions used to anodize the aluminum would eat up the copper refer lines under the lead liner. welding lead is a fun thing to learn.

What's up with the lead liner ? Why lead ? A lot of lead was used in plumbing back in the day.

[Green Mountain]

I was taught that the tank designation was from the old days, MC Meant for Motor cycle use, as in the Head light, yes bottled gas was used for lighting, and the B tank was for use for bus head lights. not sure if it is 100% correct, but thats what our instructors taught us in trade school in the 80's

Years ago I picked up a B tank refill. It had a gauge on the very bottom of the tank. The gauge was inside of the pedalstle ring so that you could still stand the tank up right. The gauge indicated Full-Empty.

For a long time I was puzzled as to why anyone would but a gauge on the bottom of a B-tank. If you were on the job soldering you would not be able to see this gauge.

Then one day I was going through the Auto Museum at Harrahs in Reno. On one of the old vehicles was a B-tank laying on its side on the fender of the car. As posted the car had aceylene head lights. The gauge on the bottom of the B-tank was easily read by the driver. :) Mystery solved.

[VTP99]

Years ago I picked up a B tank refill. It had a gauge on the very bottom of the tank. The gauge was inside of the pedalstle ring so that you could still stand the tank up right. The gauge indicated Full-Empty.

For a long time I was puzzled as to why anyone would but a gauge on the bottom of a B-tank. If you were on the job soldering you would not be able to see this gauge.

Then one day I was going through the Auto Museum at Harrahs in Reno. On one of the old vehicles was a B-tank laying on its side on the fender of the car. As posted the car had aceylene head lights. The gauge on the bottom of the B-tank was easily read by the driver. :) Mystery solved.

This thread just gets more and more interesting. Thanks for sharing.