Brazing and soldering aluminum

[Kern Dog]

Professionally done? Do you default to professionals for everything on your car?
I don't. This is my hobby and I want to learn to do as much as I can. I may fail but I'm going to try.
What one man can do, another man can do.
What would this forum be if we all just took our cars to professionals for everything?

 

[RJRENTON]

Professionally done? Do you default to professionals for everything on your car?
I don't. This is my hobby and I want to learn to do as much as I can. I may fail but I'm going to try.
What one man can do, another man can do.
What would this forum be if we all just took our cars to professionals for everything?

When you have no clue how to do something, you seek information on how to do it correctly and braising/welding aluminum falls in that category especially for a critical component. Whoever suggested the do at home method is incorrect and the results will not be what you want or expect and not worth the initial effort and $$$ expended. Your best bet is to learn the "wax on, wax off" technique........and explain it to forum.......
BOB RENTON

 

[Kern Dog]

Bob, you can read but do you ever understand what is written?
I've admitted that I'm new to this and learning. I don't expect to be great at it right away.
I didn't know how to paint a car or rebuild an engine until I did it. When was the last time you did either of those things? I'm not a checkbook restoration guy. I do as much of the work on my cars as I can.
When was the last time you started a thread where you embarked on a project and got help along the way? I've never seen even one.
I've done several and have learned something in each one.
I am always grateful for the members that offer actual help instead of suggesting that I just take it to a professional.
I'm not afraid to spend a little to learn how to do something. The savings and convenience of being able to do it myself will be worth the expense.
For example....
My thread on doing front end alignments using the Longacre gauge. Maybe you've read that one?
I learned a few things after starting the thread.
I also learned from the thread where I installed a Vintage Air system in the 68 Plymouth.

 

[Photon440]

Sort of a moot point, since MAPP (a Linde product) hasn't been made since 2008. There are yellow cylinders that look similar, labelled "MAP" or "MAP/PRO" but they aren't the same as real MAPP was.

 

[Kern Dog]

Sort of a moot point, since MAPP (a Linde product) hasn't been made since 2008. There are yellow cylinders that look similar, labelled "MAP" or "MAP/PRO" but they aren't the same as real MAPP was.

I think you’re right. The most recent canister I bought has “Map Pro” on it, I thought it was strange.
I know that there are some things with these cars that are best left to professionals due to the expense and skill level required to do the job right.
I'm adventurous though. I question the how and why just like a kid. I want to know how things work, I want to learn to do things for myself. I've seen cars at shows that were imperfect but the work was done almost entirely by the owner. Those are the cars that I liked the most.
I may never get good at brazing or soldering aluminum but I'll never know if I don't practice at it.
No kids, no job, plenty of free time and a shop out back means that I don't have anything stopping me from trying new things.

 

[Lefty71]

Sort of a moot point, since MAPP (a Linde product) hasn't been made since 2008. There are yellow cylinders that look similar, labelled "MAP" or "MAP/PRO" but they aren't the same as real MAPP was.

I had two propylene cylinders filled from a welding supplier in 7.5# size just last week. Same product stickers as always...i cant tell any difference in the heat of the gas....

I do all my hvac brazing with an oxy-mapp setup....obviously with a hose, which solves another one of Kern`s issues.

Id bet a jewelers tip would do a real nice job on the work he is describing

 

[Kern Dog]

I had two propylene cylinders filled from a welding supplier in 7.5# size just last week. Same product stickers as always...i cant tell any difference in the heat of the gas....

I do all my hvac brazing with an oxy-mapp setup....obviously with a hose, which solves another on of Kern`s issues.

Id bet a jewelers tip would do a real nice job on the work he is describing

See. it is stuff like this that is helpful.
I've had mixed luck with some of my efforts. Some projects frustrate the heck out of me to where I regret trying it.
I'm not one to just spend all my time on the couch. I want to be out there doing things.

First of all, I need to figure out to to light the damned canister. I can't seem to get the thing to light repeatedly when using the nozzle with the igniter.
Even the candle lighters like these:

They will light the gas coming out of the nozzle but once I pull them away, the flame stops. Just clicking the igniter in the "Scripto" only lights the flame for a moment. This happens with every canister that I have, even the new/full one.

 

[Kern Dog]

Here is a post from my "Vintage Air in a 68 Plymouth" thread....

Another avenue it to make your own hardline.
I ordered fittings online, some a/c tubing and aluminum soldering kit - flux and rod - and I used a map gas torch. I havn't cleaned them up yet but still holding pressure for 3 years.

and yes the port can be used for a pressure sensor or you can place it closer to the firewall.

View attachment 1593302

View attachment 1593303

View attachment 1593304

View attachment 1593305

There was a guy that had a car that may have been hard to find parts for so he took it upon himself to modify new lines to fit his car.
Kudos to that guy.

 

[Geoff 2]

Kern,
You do what you want to do. But there are smart ways to do things......& not so smart ways to do things. Trying to braze alum tubing is the latter. There is a reason that people are not doing it....

 

[6872n73]

It's only weird the first time!
I could have used hose for the length but I would have had 8 joints/crimps/ or leak paths and hard-line is a cleaner route.
I started to use OEM tube from a van/suburban that had been scrapped with long straight runs.
I found OEM tubing is thin and difficult to bend/weld.
The aluminum tubing that I purchased is dead soft material, meaning it is not tempered low alloy, very flexible. I looked on eBay/Amazon for all a/c tubing and did some research on the material they listed.
If it were to over pressure it would swell up and then rupture very nicely in a reasonable fashion. I've had my system up to 425 psi with no distortion, explosion or brain damage yet.
I did practice welding a couple of times on scrap pieces and I found it to work allot like sweating copper tubing. Applying the heat was the hardest part as aluminum transfers heat quickly so you have to develop a technique l to move the torch around quickly. From memory al melts at about 11-1200 degrees and the solder about 600 degrees so you've got some buffer but the heat transfers quickly! And the solder flows quickly afterwards.
This is the same for fittings.
It's been 4 ish years now with no leaks, so I'm either lucky with all the other a/c repair technicians or with a little preparation its not that hard, like so many other things in life.

 

[zyzzyx]

First of all, Aluminum can't be "Brazed". It has to be T.I.G. welded. you have everything there to make the
hose come out the way you want, all you have to do is have the system evacuated and take the line off.
Cut the long straight horizontal aluminum line shorter, clock it where you want it and have someone T.I.G.
the tubes back together. No fuss, no mess! Don't over think it. And by the way, one of the main reasons that
MAPP gas fell by the wayside is that Propane puts out way more B.T.U.'s than MAPP, or Acetylene for that matter.

 

[RJRENTON]

Bob, you can read but do you ever understand what is written?
I've admitted that I'm new to this and learning. I don't expect to be great at it right away.
I didn't know how to paint a car or rebuild an engine until I did it. When was the last time you did either of those things? I'm not a checkbook restoration guy. I do as much of the work on my cars as I can.
When was the last time you started a thread where you embarked on a project and got help along the way? I've never seen even one.
I've done several and have learned something in each one.
I am always grateful for the members that offer actual help instead of suggesting that I just take it to a professional.
I'm not afraid to spend a little to learn how to do something. The savings and convenience of being able to do it myself will be worth the expense.
For example....
My thread on doing front end alignments using the Longacre gauge. Maybe you've read that one?
I learned a few things after starting the thread.
I also learned from the thread where I installed a Vintage Air system in the 68 Plymouth.

Front alignment procedures are well worth the cost and accuracy (laser) rather than some at home method. I prefer to use the car for fun. (Try going to the Woodward Ave Dream Cruise or local outings) rather than constantly looking for things to do and trying to explain in adinfinitum detail about minutia, aka degrees of distributor advance or centrifugal limiter advance plate installation in your specific application or torqing tire valve stem caps properly or how the cooling system operates......you must feel compelled to say something perhaps you should author a blog...."How I do things" and charge for your opinions, that way you'll know just how valuable they are....
BOB RENTON

 

[moparx]

My recent experiences with automotive air conditioning installations have me curious about modifying hard lines to make a more custom fitted system.
Here is an example.....My own '70 Charger.

View attachment 1696908

The #8 aluminum line is prebent by Classic Auto Air to fit around a battery. My battery is in the trunk. I would like to have the ability to shorten the hard line like this:


View attachment 1696909

To do that, I need to learn how to braze aluminum.
I've never welded with a torch so I'm learning as I go here. I can stick and MIG weld, I can solder wires but that is about it.
I have a few Propane and Mapp gas cannisters like these:


View attachment 1696910

So far, the most commonly found nozzles look like these:


View attachment 1696911
The cannisters warn against inverting them when in use but how am I supposed to apply the flame when the work I'm doing is barely above waist high? I'm not trying to do the work overhead where the nozzle points. It would be great if there were nozzles that had a swivel.
With these types of nozzles, You have to tilt the nozzle to get it where you want it. There are those nozzles with a hose that I could try.

I recently was at an A/C shop helping out a friend with his Coronet. You might remember the guy....

View attachment 1696912

He had a line shortened and brazed back together and it got me thinking.
What ONE man can do, another man can do. If I can get good at doing this, I'll be able to route A/C lines wherever I want and not be limited by the stock sizes that you buy at the store.

My first effort SUCKED though.

looking at the first picture of the line as it is currently, then looking at the diagram of the routing you want to utilize, i would just cut the line at the fitting nut, shorten to the length you want/need, then reinstall the nut and re-flair the tube end. seems like it couldn't be any simpler than that ?
or am i missing something ?

 

[Kern Dog]

First of all, Aluminum can't be "Brazed". It has to be T.I.G. welded. you have everything there to make the
hose come out the way you want, all you have to do is have the system evacuated and take the line off.
Cut the long straight horizontal aluminum line shorter, clock it where you want it and have someone T.I.G.
the tubes back together. No fuss, no mess! Don't over think it. And by the way, one of the main reasons that
MAPP gas fell by the wayside is that Propane puts out way more B.T.U.'s than MAPP, or Acetylene for that matter.

Thanks for chiming in but you are wrong on two accounts.
Aluminum can be brazed or soldered. I've seen it in person. NO welding, just a gas torch and filler rod and once scuffed and buffed, the line looked undisturbed. Seeing that inspired me to learn how to do it myself.
I've seen numerous videos showing people braze/solder aluminum tubes and flat plates together with just a Map or Propane torch and aluminum rod.

Secondly.....
Mapp burns hotter than propane too.

 

[Lefty71]

operates......you must feel compelled to say something perhaps you should author a blog...."How I do things" and charge for your opinions, that way you'll know just how valuable they are....

I dont want to take his thread off track, but hes contributed more to the fellowship of this site than you ever will, without looking down his nose at everyone who asks a question (spelling and grammer excluded lol). You should aspire to be more like him.

 

[RJRENTON]

Thanks for chiming in but you are wrong.
I've seen numerous videos showing people braze/solder aluminum tubes and flat plates together with just a Map or Propane torch and aluminum rod.
Mapp burns hotter than propane too.


View attachment 1697644

I'm well aware of the properties of MAPP gas and its costs. You never see the test results of brazing/soldering aluminum. Attaching a plate to a plate (butt joint or lap joint or FULL PENETRATION bevel joint) or other configurations and tubing requires totally different preparation techniques. Small diameter tubing is typically gas backed during joining. Do you even know what that means? How about tensile strength testing, bend testing, or pressure testing at working temps, where the final test is 1.4x maximum allowable working pressure (MAWP. ) I also have AWS (American Welding Society Section D1-1 structural welding credentials). You are just too naive to take someone's word as gospel or some videos for their results without adequate testing or showing the physical preparation techniques used....you only see the edited version....not the failures. I have Class II Welding/inspection credentials (review of weld x-rays, aka "shooters sheets") and can do ASME Section VII Division 2 Code calcs and Weld Procedure Specifications (WPS) and their Procedure Qualification Records (PQR) necessary for Code welding. Perhaps you should stick to the "wax on wax off" techniques and principles ......
BOB RENTON

 

[Photon440]

First of all, Aluminum can't be "Brazed". It has to be T.I.G. welded. you have everything there to make the
hose come out the way you want, all you have to do is have the system evacuated and take the line off.
Cut the long straight horizontal aluminum line shorter, clock it where you want it and have someone T.I.G.
the tubes back together. No fuss, no mess! Don't over think it. And by the way, one of the main reasons that
MAPP gas fell by the wayside is that Propane puts out way more B.T.U.'s than MAPP, or Acetylene for that matter.

Aluminum can certainly be soldered, ask any farmer with aluminum irrigation piping.

 

[1 Wild R/T]

I dont want to take his thread off track, but hes contributed more to the fellowship of this site than you ever will, without looking down his nose at everyone who asks a question (spelling and grammer excluded lol). You should aspire to be more like him.

Well Stated... Very nice & polite... I'm not that nice... As I see it BOB RENTON is an asshole...

 

[RJRENTON]

First of all, Aluminum can't be "Brazed". It has to be T.I.G. welded. you have everything there to make the
hose come out the way you want, all you have to do is have the system evacuated and take the line off.
Cut the long straight horizontal aluminum line shorter, clock it where you want it and have someone T.I.G.
the tubes back together. No fuss, no mess! Don't over think it. And by the way, one of the main reasons that
MAPP gas fell by the wayside is that Propane puts out way more B.T.U.'s than MAPP, or Acetylene for that matter.

Absolutely correct.....and preparation is critical to success, using the tried and true methods.....
BOB RENTON

 

[RJRENTON]

I dont want to take his thread off track, but hes contributed more to the fellowship of this site than you ever will, without looking down his nose at everyone who asks a question (spelling and grammer excluded lol). You should aspire to be more like him.

If something is worth doing, then do it the correct way.......perhaps the old live and learn principle applies ??
BOB RENTON