Alternative to brazing?

[aenigma]

You are correct. Anybody can put a unit together and have it run. I have seen many hack jobs out there (In my field). They did run, and worked to a point. The one thing that none of them did was last. That is where the correct oil, correct vaccum, correct brazing, correct purging comes into play. It really is not that big a deal to chnage out a compressor on a unit. The big deal is to do it right so that it will last.
In Air conditioning there is alot of room for error. The comps tolerances arnt as tight, they dont run for extended periods of time, the temps are above freezing. The life expectancy of theunit is under 10 years.
In refrigeration the room for error is smaller but still manageable. Life expectancy is under 10 years.
In cascades life expectancy is over 10 years, the comp tollerances are critical (the 3/4hp I buy are over $1000), the comps are expected to run 90% of the time. Long cap tubes so any moisture blocks them.

The rebuilding process is a step by step process. Its not just replacing a comp it is following a procedure to ensure a very long life of the equipment.

Just my $0.002 worth (not a flame thing type of post either)

Boogerlad,
There is a reason that there is no alternative to brazing. Nothing has been found to be better. Even HVAC solder cannot take the vibrations or punishment produced by refrigeration systems.

Yeah, that is very true. I was mentioning it because people making their first unit don't have to get everything just right and spend a thousand dollars on tools. They are most likely going to be making another one in less than a month, so it doesn't need to last as it's just for practice. Once they learn about it they can start investing some money into the hobby and put the tools to good use and make better refrigeration systems. Otherwise they might be spending a bunch of money on something they may not want to keep doing.

What were temps like?

These weren't used to cool a cpu, I think I made most of them as water chillers. This was probably up to 8 years ago and I was building these things to learn, so I don't really remember. I think the average temperature I was seeing was about -40c without a load, unless I was using a small compressor or something. I wasn't saying I would trust any of those compressors with holes drilled in them, just that they never gave me problems even though they were left outside in the weather. I also want to mention that I did use a vacuum pump, it's just that the compressors themselves would be considered garbage.

The best thing I got from that junk yard was a condensing unit with a 1/6hp tecumseh compressor and I've used everything but the compressor on my autocascade. It made a perfect base plate to build on, it already had the condenser with fan and shroud and I used the receiver as an expansion tank. Man, I loved that junk yard!

[Sn@ke:~]

I just want to jump in to say that you can ionize your Aluminum and it won't rust anymore.

It is quite easier than cheap thought, You need a bath of acid electrically charge and just sunk the piece of Aluminum into the acid for the necessary time requested by the procedures. That is what they do for pieces of airplane. It is basically rusting the Aluminum at very fast speed creating a hard crust surface lair that won't ever rust again. If you weld you have to do it after welding and don't ever use pencil on Aluminum it will rust and weaken the area of application causing to crack and brake.

There is also a similar process for steel.

And welding Aluminum is the hardest skills in welding profession because you can past the melting point and you can't weld under the melting point you also have to go on a continuous motion until the whole welding straight is done and even after you need a small pick hammer and the the welded section to see if it's crack. In aerospace ht to see if the industry they will soak the pieces into a liquid and look at it with black light to see if the welded section is no crack and upi to he job.