Announcement

Collapse
No announcement yet.

Vacuum Potting in the "At Home" Shop

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

  • Vacuum Potting in the "At Home" Shop

    Thought I'd post a little video so anyone interested could see just how fast and furious the air is extracted from pickup with a single stage vacuum pump. I wish the video had been a little better, but you'll get the idea!

    Vacuum Potting - YouTube

    Last set I did for nearly 2 minutes. This set. . . ~ 30 seconds before I pulled the plug.
    Take Care,

    Jim. . .
    VA3DEF
    ____________________________________________________
    In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

  • #2
    Great Video!
    You make me feel obsolete, and old fashioned with my non Vacuum mode!
    T
    "If Hitler invaded Hell, I would make at least a favourable reference of the Devil in the House of Commons." Winston Churchill
    Terry

    Comment


    • #3
      Originally posted by big_teee View Post
      Great Video!
      You make me feel obsolete, and old fashioned with my non Vacuum mode!
      T
      You have skills Terry, I just have curiosity.

      But does that look like it's is sucking the air out or what!
      Take Care,

      Jim. . .
      VA3DEF
      ____________________________________________________
      In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

      Comment


      • #4
        Jim. . .

        Who makes that vacuum pump? Is it a Gast? Was it for automotive refrigerant recovery?

        Comment


        • #5
          Originally posted by David King View Post
          Jim. . .

          Who makes that vacuum pump? Is it a Gast? Was it for automotive refrigerant recovery?
          It's just a cheap little no name "Made in China" single stage vacuum pump identical to the one sold by Harbor Freight for ~ $90. It pulls 30 inches of vacuum based on two different sets on gauges I have (one of which I used to use when I did air conditioner repair work back in the day).
          Attached Files
          Take Care,

          Jim. . .
          VA3DEF
          ____________________________________________________
          In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

          Comment


          • #6
            Originally posted by kayakerca View Post
            ... identical to the one sold by Harbor Freight for ~ $90...
            This one?

            http://www.harborfreight.com/25-cfm-...ump-98076.html
            -Brad

            ClassicAmplification.com

            Comment


            • #7
              Originally posted by RedHouse View Post

              Wow, it's gone up $10 since I started the this thread. That is basically it other than only one size fitting to the gauges and 2.5 cfm vs. 3 cfm.

              Here is the exact one I bought off ebay.

              http://www.ebay.com/itm/R410a-1-Stag...item4606d79350
              Take Care,

              Jim. . .
              VA3DEF
              ____________________________________________________
              In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

              Comment


              • #8
                The ebay one goes down to 5Pa whereas the HF one is rated to 10 pascals. Somewhere there's a table that will convert Pa or pascals to inches of mercury. It's right around 29"/Hg but the Ebay one looks like a better deal all around.
                I didn't think a single stage rotary vane could pull that kind of vacuum.

                Comment


                • #9
                  Originally posted by David King View Post
                  The ebay one goes down to 5Pa whereas the HF one is rated to 10 pascals. Somewhere there's a table that will convert Pa or pascals to inches of mercury. It's right around 29"/Hg but the Ebay one looks like a better deal all around.
                  I didn't think a single stage rotary vane could pull that kind of vacuum.
                  Definitely not the quality of pump I used when I did component work on window air conditioners, but it puts 30 inches on the same set of gauges (over a much smaller volume of my mini crockpot). If you have a look at the little video I did, you have to ask yourself if you have ever seen so much air removed from a set of pickups being potted. :-)
                  Take Care,

                  Jim. . .
                  VA3DEF
                  ____________________________________________________
                  In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

                  Comment


                  • #10
                    Originally posted by kayakerca View Post
                    Definitely not the quality of pump I used when I did component work on window air conditioners, but it puts 30 inches on the same set of gauges (over a much smaller volume of my mini crockpot). If you have a look at the little video I did, you have to ask yourself if you have ever seen so much air removed from a set of pickups being potted. :-)

                    I was wondering if some of that was from the wax, maybe not all of it was air in the coil?.
                    -Brad

                    ClassicAmplification.com

                    Comment


                    • #11
                      Originally posted by RedHouse View Post
                      I was wondering if some of that was from the wax, maybe not all of it was air in the coil?.
                      Interesting question. Any chemists in the crowd?

                      I'll be potting some this week. I run the pump against the liquid wax and see what happens. I'll be surprised if much air is saturated into the liquid wax, especially after it has been evacuated a bunch of times potting pickups. I would suspect that the same principle would apply to non vacuum potting as well. If the air is removed easier in non vacuum potting, the same would apply in vacuum potting, and at some point, all the air that could be removed from the wax at the level of vacuum used would be liberated and all subsequent potting would extract only air from the pickups. Anyway, I'll test it and see.
                      Take Care,

                      Jim. . .
                      VA3DEF
                      ____________________________________________________
                      In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

                      Comment


                      • #12
                        It would be easy to check the intake filter for signs of wax building up if it is boiling off at low pressure.

                        Comment


                        • #13
                          Originally posted by David King View Post
                          It would be easy to check the intake filter for signs of wax building up if it is boiling off at low pressure.
                          If wax were being extracted from the potting process, the gauges gumming up and not operating would probably be the first sign. I don't know if there are any filters on evacuation pumps of this style and there do not appear to be any that are intended to be accessed and maintained.
                          Take Care,

                          Jim. . .
                          VA3DEF
                          ____________________________________________________
                          In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

                          Comment


                          • #14
                            Originally posted by David King View Post
                            It would be easy to check the intake filter for signs of wax building up if it is boiling off at low pressure.
                            No I didn't mean "wax" I meant other things in the parrafin/bee's wax, assuming of course, that's what he was using.

                            I don't know, like oils which might have some compounds that gass-off under heat and extreme vaccume.
                            -Brad

                            ClassicAmplification.com

                            Comment


                            • #15
                              Originally posted by RedHouse View Post

                              I don't know, like oils which might have some compounds that gass-off under heat and extreme vaccume.
                              The oil in the vacuum pump is intended to a medium for trapping gas molecules being extracted. Not sure how you would determine what exactly was being drawn off during the process.
                              Take Care,

                              Jim. . .
                              VA3DEF
                              ____________________________________________________
                              In the immortal words of Dr. Johnny Fever, “When everyone is out to get you, paranoid is just good thinking.”

                              Comment

                              Working...
                              X