Announcement

Collapse
No announcement yet.

How do you sweat AC copper tubing?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • How do you sweat AC copper tubing?

    I have an ac install to do but i don't know what to use to sweat the copper lines together. I have heard people say that you shouldn't solder them, you should braze them, but no one can tell me what kind of brazing/flux to use. Do you guys know?
    Dynasty 200 DX
    Millermatic 175
    Spectrum 375
    All kinds of Smith OA gear

  • #2
    I know a couple of my buds have been using common lead free, seems to work. Most common though is something like silver 45 and white flux for silver.

    Comment


    • #3
      Use 430 degree soft solder, w/acid liquid or paste flux. Clean well, use flame. Flux & solder should be available at LWS or home store.
      AutoArc 230 (MM 210)
      3035 spoolgun
      Spectrum 625
      Dialarc HF w/Coolmate 4

      Comment


      • #4
        Don't forget the emory cloth

        My dad showed me this and it has worked every time. We use a small piece of emery cloth to clean and polish the end of the copper line before applying the flux and lead free solder. You can roll a small piece to clean the inside of the fitting being attached too. You can just preheat the fitting a tad before applying the flux so that it will flow evenly over the joint before mating. It doesn't take much at all. Had to do some work on the refrigerator water line the other day to replace some parts of dissimilar metal that had grown shut with rust. Properly cleaned ends with proper flux and lead free solder should do the trick. The label directions on the flux and solder can be helpful too. Also, a good acetylene torch works well too. NOT O/A just acetylene. Be sure to look in the plumbing department at your local hardware store or big box store.
        '77 Miller Bluestar 2E on current service truck
        '99 Miller Bobcat 225NT for New Service Truck
        '85 Millermatic 200 in Shop

        '72 Marquete 295 AC cracker box in Shop
        '07 Hypertherm Powermax 1000 G3 Plasma Cutter in Shop
        Miller Elite and Digital Elite Hoods

        Comment


        • #5
          careful with the flux too much left in the joint and it will eat the copper from the inside out.
          It only takes a whisper thin amount I used an empty jar of flux for two weeks just using what had soaked into the brush.

          Put the flame on one side and the solder on the other when the solder starts to melt remove the heat stroke the solder around the joint once. let it set up for a minute then take a damp rag and wipe the joint and remove all excess flux.


          Tj
          TJ______________________________________

          Comment


          • #6
            SBerry is right,
            Dont use ordinary solder that you use on copper water pipes- that is solering.

            I use Silver solder which melts at a higher temputure, you want a 45% silver content and yes the flux I use is a white paste, when flux turns clear add the filler.
            The silver solder is a stronger joint and will stand up to the vibration of the compressor.
            And of course clean it before hand.

            When you silver solder you will need an oxy/ acyt. torch with a very small tip.

            Comment


            • #7
              Originally posted by Portable Welder
              When you silver solder you will need an oxy/ acyt. torch with a very small tip.
              i agree with Flukecej, no O/A till you're proficient, use a air/acetylene or a MAPP torch, the O/A can melt the Cu tube way fast and in a hurry if you aren't watching.

              Comment


              • #8
                If you were licensed to do the work, you would already know.....but if you insist, you can use Silfos 6% sticks that may be purchaced separately sometimes, cheapest, or 45% silver solder with flux. When it comes to charging the system, get a licensed guy or pay the fine if you get caught. Nick...HVAC tech .....since 1971
                Nick
                Miller 252 Mig
                Miller Cricket XL
                Millermatic 150 Mig
                Miller Syncrowave 200 Tig
                2-O/A outfits
                Jet Lathe and Mill
                Jet 7x12 horz/vert band saw
                DeWalt Multi Cutter metal saw
                Century 50 Amp Plasma Cutter
                20 ton electric/hydraulic vertical press
                Propane Forge
                60" X 60" router/plasma table

                www.youtube.com/watch?v=jTu7wicVCmQ
                Vist my site: www.nixstuff.com
                and check out some of my ironwork and other stuff

                Comment


                • #9
                  thanks for the replies.

                  I know your not supposed to use solder and flux (water pipe stuff) since it can contaminate the freon and damage the compressor.

                  Most sites reccommend brazing, but with what exactly i do not know.

                  I've heard silfos before and will look for it.

                  Unit is precharged, all i have to do is connect the lines and purge (according to the directions).

                  Get a licensed AC guy?? Come on, i've been working on auto ac stuff for 18 years, airplanes, computers, SANs, networks, houses, Welding, engines .................................................. .................................................. ........ etc. etc. etc.
                  I don't have a license for any of it!!!! (except the airplanes!)
                  Dynasty 200 DX
                  Millermatic 175
                  Spectrum 375
                  All kinds of Smith OA gear

                  Comment


                  • #10
                    OK, so now you solder the lines to the ac unit and evaporator coil. Now are your solder joints leaking? Well after you release the charge to the lines, I guess you'll find out. If not, great. What if they are, then what will you do?
                    You can't resolder the lines with pressure in them. Now you'll have to capture the refrigerant somehow and redo the leaks. I hope you leak test the next time but with what? I use nitrogen which can be vented to the atmosphere
                    legally. If no leaks I evacuate the system with a pump, release the charge and check for correct amount refrigerant depending on the coil size, length and size of lines. Some units may be undercharged at the factory. Are you using the freon to leak lest and then purging, which lowers the charge amount. By the way, have you installed the correct size filter drier in the
                    liquid line? Good luck with your install.
                    Nick
                    Miller 252 Mig
                    Miller Cricket XL
                    Millermatic 150 Mig
                    Miller Syncrowave 200 Tig
                    2-O/A outfits
                    Jet Lathe and Mill
                    Jet 7x12 horz/vert band saw
                    DeWalt Multi Cutter metal saw
                    Century 50 Amp Plasma Cutter
                    20 ton electric/hydraulic vertical press
                    Propane Forge
                    60" X 60" router/plasma table

                    www.youtube.com/watch?v=jTu7wicVCmQ
                    Vist my site: www.nixstuff.com
                    and check out some of my ironwork and other stuff

                    Comment


                    • #11
                      hi, depending where you are located you can use STAY-BRITE soft solder and stay- clean flux for your AC condersing and evaporator coil. This is a silver content soft solder similiar to water piping solder but COSTLY. This flows just like 95/5 . Be careful not to fill joint too much and sea line shut. that small liquid line doesn't take much. MAKE sure the orifice in evap coil matches what the condenser requires. If same manufacture they normal ship what is required with condenser to be installed at coil. Hope this helps. Make sure you test and evacuate BEFORE opening valves at condenser and blow charge in compressor.

                      Comment


                      • #12
                        Originally posted by monte55
                        ...but if you insist, you can use Silfos 6% sticks...
                        Or 15% if you are experienced.

                        Comment


                        • #13
                          Thanks for all the concerns.

                          The unit is a sanyo split mini ductless. It comes precharged, there is a purge procedure in the manual. I have access to a gauge set and r22 and could either evacuate the lines or pressure test them (any reason i cant use c25 or argon?). there is also a procedure to collect the referigerant using the compressor. Normally these units only use a flare but my routing is a little convoluted so i will need at least one elbow maybe 2 to make it neat. The high side is only 1/4 so i think i can avoid any brazing there.

                          Do you guys know what type of flare they use? i assume 37 or 45 but incredibly the instructions don't specify. They only say a "RIGID" flaring tool.

                          I was planning to use mapp gas but in a pinch i have OAW, it seems you guys think a rosebud would be difficult to handle?

                          Thanks again for the help.
                          Dynasty 200 DX
                          Millermatic 175
                          Spectrum 375
                          All kinds of Smith OA gear

                          Comment


                          • #14
                            i would defenetly go with the map gas, plenty of heat ive used it for the siver soder and its a lil harder to melt away the tubing itself. dont get slopy though the map gas will still melt the tube if you are not watching it.
                            thanks for the help
                            ......or..........
                            hope i helped
                            sigpic
                            feel free to shoot me an e-mail direct i have time to chat. james@newyorkmetalart.com
                            summer is here, plant a tree. if you don't have space or time to plant one sponsor some one else to plant one for you. a tree is an investment in our planet, help it out.
                            JAMES

                            Comment


                            • #15
                              Laiky, all I can say is, I hope this AC job is on your property and your money.

                              Comment

                              Working...
                              X