Swiftech
Page 1 of 2 12 LastLast
Results 1 to 25 of 34

Thread: Alternative to brazing?

  1. #1
    Xtreme Addict
    Join Date
    Feb 2007
    Posts
    1,673

    Alternative to brazing?

    this is the only forum here that involves brazing, and it appears you need high temperatures and some skill to braze properly. Would something like http://www.durafix.com/ work? Would you still have to deal with oxidization? I think it would withstand the pressure within an ss unit, but am not sure... Any opinions?

    Thanks

  2. #2
    Xtreme Mentor teyber's Avatar
    Join Date
    Feb 2007
    Location
    Victoria, British Colombia
    Posts
    2,677
    for brazing copper? for these systems which often see 300psig/22bar or so its really important to use at least 15% silver brazing rods. you can use a mapp torch
    mentally confused and prone to wandering

  3. #3
    Xtreme Addict
    Join Date
    Feb 2007
    Posts
    1,673
    would the stuff i mentioned be strong eneough? If it was strong enough, would it be easier to use? What temp does copper oxidize really fast?

  4. #4
    Diablo 3! Who's Excited? [XC] gomeler's Avatar
    Join Date
    May 2005
    Location
    Boulder, Colorado
    Posts
    9,440
    Durafix looks like a low-temp braze for aluminum. Won't work seeing as we used copper in our systems. Brazing is easy work, just takes a little patience.

  5. #5
    Xtreme Addict
    Join Date
    Feb 2007
    Posts
    1,673
    if you watch the video, it does copper too. I was surprised as well. Do aluminum evaporators work, or would there be galvanic corrosion?

  6. #6
    Xtreme Enthusiast sjg0's Avatar
    Join Date
    Jun 2008
    Location
    Chandler, AZ
    Posts
    573
    I dont exactly see what the point of this would be. The only difference is this you can use propane instead of MAPP. You still need (semi) high temperatures and skill brazing. And the aluminum is weaker...
    #1
    Pentium D805 @ 3.4Ghz on GA-945P-S3
    2Gb OCZ Gold 800 with XP Professional SP3
    Ati X1800XT
    550W Antec TruPower in Antec Sonata II
    #2
    Core 2 Quad Q9550 on GA-EP45-UD3P
    4Gb Corsair Dominator 1066 with Vista Ultimate SP1
    Asus 4850 TOP
    750W PC Power & Cooling in ????


    There is not enough electrical oulets in my room.
    Best TF2 Quote:
    "tomtom92 : wtf the enemy has a base IN our base"

  7. #7
    Xtreme Mentor teyber's Avatar
    Join Date
    Feb 2007
    Location
    Victoria, British Colombia
    Posts
    2,677
    Quote Originally Posted by Boogerlad View Post
    if you watch the video, it does copper too. I was surprised as well. Do aluminum evaporators work, or would there be galvanic corrosion?
    Galvanic corrosion isn't really a worry for phase change, just watercooling. galvanic corrosion doesn't just happen for aluminum but for any dis-similar metals, many compressors use seals that are aluminum and havn't had any problems. Also its when with a conductive material between the two dissimilar materials, im not sure if hfc's are conductive

    Aluminum is tricky as its not quite strong enough to use as an evaporator, hopefully someone proves me wrong but at least chilly1 had frustrations with alu
    mentally confused and prone to wandering

  8. #8
    Registered User plasmatique's Avatar
    Join Date
    Feb 2008
    Location
    Reunion (France D'Outre Mer)
    Posts
    60
    http://www.vulkan.fr/lokring/2006/raccord/raccord.htm

    You could use this but it returns a lot

  9. #9
    Diablo 3! Who's Excited? [XC] gomeler's Avatar
    Join Date
    May 2005
    Location
    Boulder, Colorado
    Posts
    9,440
    Or you could just braze the copper together and form a solid seal

  10. #10
    Xtreme Mentor teyber's Avatar
    Join Date
    Feb 2007
    Location
    Victoria, British Colombia
    Posts
    2,677
    yeah im with gomeler- brazing really isn't a big deal at all
    mentally confused and prone to wandering

  11. #11
    Xtreme Mentor sdumper's Avatar
    Join Date
    Aug 2006
    Location
    Atlanta
    Posts
    3,279
    Its not the brazing its the buying of a Nitrogen tank, regulator and then playing with just the right purging pressure which can be a pain for someone just starting.
    I went through a ton of nitrogen at first until I realized I just needed to displace the oxygen in the line I was brazing and not maintain pressure blowing through it.

    All of that said I would just go with a MAPP torch and the cheapest purging setup you can put together...for SS Co2 is fine...
    Never empower an idiot with a response....

    http://en.wikipedia.org/wiki/Troll_%28Internet%29

    Seller/Buyer Reputation:
    Heatware: http://www.heatware.com/eval.php?id=50905
    Ebay: {Family Account} Kasyg3 http://myworld.ebay.com/kasyg3/
    Ebay: {My personal Account} Sdumper http://myworld.ebay.com/sdumper/
    iTrader: http://www.blazingpc.com/forum/itrader.php?u=28

  12. #12
    Xtreme Addict SexyMF's Avatar
    Join Date
    Nov 2005
    Location
    Auckland, New Zealand
    Posts
    1,076
    It is not absolutely necessary to:

    1) Change compressor oil because it's been open to air for a few days
    2) Purge during brazing (Propane is fine as a shield gas. Safer than lighting a BBQ)
    3) Use a proper vacuum pump to evacuate the system
    4) Bother with a high side access valve
    5) Insert a filter/dryer

    The only thing you do need is a MAPP torch, guages and some self fluxing rods like Silfoss. Vacuum pump can be made from freezer compressor.

  13. #13
    Xtreme Member godmod's Avatar
    Join Date
    Jul 2005
    Location
    Austria
    Posts
    430
    Quote Originally Posted by SexyMF View Post
    Vacuum pump can be made from freezer compressor.
    An offense to all the real vacuum pumps out there...

  14. #14
    Xtreme Mentor sdumper's Avatar
    Join Date
    Aug 2006
    Location
    Atlanta
    Posts
    3,279
    Still I wouldn't want risk a poor vacuum and freezing moisture/corrosion build up in my lines because of it.
    Never empower an idiot with a response....

    http://en.wikipedia.org/wiki/Troll_%28Internet%29

    Seller/Buyer Reputation:
    Heatware: http://www.heatware.com/eval.php?id=50905
    Ebay: {Family Account} Kasyg3 http://myworld.ebay.com/kasyg3/
    Ebay: {My personal Account} Sdumper http://myworld.ebay.com/sdumper/
    iTrader: http://www.blazingpc.com/forum/itrader.php?u=28

  15. #15
    Xtreme Addict SexyMF's Avatar
    Join Date
    Nov 2005
    Location
    Auckland, New Zealand
    Posts
    1,076
    Still I wouldn't want risk a poor vacuum and freezing moisture/corrosion build up in my lines because of it.
    I don't mean this in a flame war kind of way but quantify the statement. How much moisture is in a system and how much damage could it do over the lifetime of the system? I built several systems using two in-series freezer compressors as a vacuum pump. I'm not the first. Never had a problem. It wasn't till later I purchased a vacuum pump. If I'm not fussed why did I bother purchasing the pump? because it does't a better job, but primarily because it does it faster.

    To make a refrigeration system is very easy. To make it work to specs takes knowledge and calculations. I would pick the person with design skill and less tooling to make a better system than a rookie with all the kit.

    It is obvious in this forum that there are only a handful of people who can do the required calculations and who innovate. The rest just copy (which works fine, to a point)


    I degress somewhat

  16. #16
    Xtreme Mentor sdumper's Avatar
    Join Date
    Aug 2006
    Location
    Atlanta
    Posts
    3,279
    Quote Originally Posted by SexyMF View Post
    I don't mean this in a flame war kind of way I would pick the person with design skill and less tooling to make a better system than a rookie with all the kit.

    It is obvious in this forum that there are only a handful of people who can do the required calculations and who innovate. The rest just copy (which works fine, to a point)



    SexyMF it sounds like you had your feathers ruffled a bit but if you were trying to flame me then it certainly wasnt taken that way

    I was not bashing making a makeshift vacuum pump I was referring to not vacuuming at all and having your lines freeze periodically from having moisture in your system...

    Hopefully with that clarification you wont be so upset
    Never empower an idiot with a response....

    http://en.wikipedia.org/wiki/Troll_%28Internet%29

    Seller/Buyer Reputation:
    Heatware: http://www.heatware.com/eval.php?id=50905
    Ebay: {Family Account} Kasyg3 http://myworld.ebay.com/kasyg3/
    Ebay: {My personal Account} Sdumper http://myworld.ebay.com/sdumper/
    iTrader: http://www.blazingpc.com/forum/itrader.php?u=28

  17. #17
    -110c club EvoCarlos's Avatar
    Join Date
    May 2008
    Location
    by the LAMP!
    Posts
    553
    i still say 55% silver solder and a propain torch
    its done all what i have build

    and tho's professional vac pumps are great lol
    I LOVE LAMP!

  18. #18
    Xtreme Member
    Join Date
    Aug 2002
    Location
    Washington
    Posts
    296
    I used an a/c rotary compressor for a long time as a vacuum pump and it worked fine. I am back to my real vacuum pump now that I fixed it recently. The real vacuum pump is quieter and I don't worry about leaving it running for a long time like I did with the a/c compressor since it gets very hot.

    If you are using a compressor that doesn't pull enough of a vacuum, that's not a big problem, just heat the phase change unit up to help remove moisture. Especially the drier. It's also a good idea to vacuum then purge a few times to ensure there is no air in the system.

    It is not absolutely necessary to:

    1) Change compressor oil because it's been open to air for a few days
    2) Purge during brazing (Propane is fine as a shield gas. Safer than lighting a BBQ)
    3) Use a proper vacuum pump to evacuate the system
    4) Bother with a high side access valve
    5) Insert a filter/dryer
    Very true. A lot of the stuff I built back in the day was from a junk yard, and the compressors all had holes drilled in them to drain the oil! No, I didn't add more oil or change oil or anything, I just used them! Not only were the compressors open for a few days, they were probably rained on as well.

    I never used to purge either, it matters much less when brazing smaller stuff. It's when you braze large pipes for something like a receiver or when brazing an evap that it's important, but still not needed of course. You can just blow the evap out with compressed air or something to get the loose pieces out.

  19. #19
    Xtreme Addict
    Join Date
    Feb 2007
    Posts
    1,673
    here are the specs of the durafix easyweld stuff. From reading it, it's about 54% of the strength of silver brazing i think
    Attached Images Attached Images

  20. #20
    Xtreme Enthusiast sjg0's Avatar
    Join Date
    Jun 2008
    Location
    Chandler, AZ
    Posts
    573
    Quote Originally Posted by aenigma View Post
    Very true. A lot of the stuff I built back in the day was from a junk yard, and the compressors all had holes drilled in them to drain the oil! No, I didn't add more oil or change oil or anything, I just used them! Not only were the compressors open for a few days, they were probably rained on as well.
    What were temps like?
    #1
    Pentium D805 @ 3.4Ghz on GA-945P-S3
    2Gb OCZ Gold 800 with XP Professional SP3
    Ati X1800XT
    550W Antec TruPower in Antec Sonata II
    #2
    Core 2 Quad Q9550 on GA-EP45-UD3P
    4Gb Corsair Dominator 1066 with Vista Ultimate SP1
    Asus 4850 TOP
    750W PC Power & Cooling in ????


    There is not enough electrical oulets in my room.
    Best TF2 Quote:
    "tomtom92 : wtf the enemy has a base IN our base"

  21. #21
    Xtreme Member ultralo1's Avatar
    Join Date
    Oct 2008
    Location
    NC
    Posts
    359
    Quote Originally Posted by aenigma View Post
    Very true. A lot of the stuff I built back in the day was from a junk yard, and the compressors all had holes drilled in them to drain the oil! No, I didn't add more oil or change oil or anything, I just used them! Not only were the compressors open for a few days, they were probably rained on as well.

    I never used to purge either, it matters much less when brazing smaller stuff. It's when you braze large pipes for something like a receiver or when brazing an evap that it's important, but still not needed of course. You can just blow the evap out with compressed air or something to get the loose pieces out.
    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.

  22. #22
    Xtreme Member
    Join Date
    Aug 2002
    Location
    Washington
    Posts
    296
    Quote Originally Posted by ultralo1 View Post
    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.

    Quote Originally Posted by sjg0 View Post
    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!

  23. #23
    Xtreme Member Sn@ke:~'s Avatar
    Join Date
    Mar 2008
    Location
    Canada
    Posts
    356
    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.
    Last edited by Sn@ke:~; 02-28-2009 at 08:35 AM.

  24. #24
    Xtreme Member Athanatos's Avatar
    Join Date
    Mar 2007
    Location
    Tripoli, Greece; Toronto, Canada
    Posts
    137
    i think that duraweld a croc
    aluminum welding is not easy like that at all, it requires specific heat, speed of the filler metal (tig rod or wire if using mig) to make a proper weld
    since aluminum absorbs heat very fast, it would be required to use pieces of aluminum or copper clamped to the work area to absorb the excess heat so that the weld will turn out right

  25. #25
    Xtreme Addict SexyMF's Avatar
    Join Date
    Nov 2005
    Location
    Auckland, New Zealand
    Posts
    1,076
    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.
    True but the useful life of a phase change system for a computer is really only ~2 years. CPU generations are fast and to keep up you have to rebuild anyway.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •