Vacuum pump

Discussion in 'Fiberglass and Composite Boat Building' started by weldandglass, Mar 14, 2011.

  1. weldandglass
    Joined: May 2010
    Posts: 23
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Gulf Coast of Texas

    weldandglass Junior Member

    I vacuum bagged two bulkhead panels last night using a robinair 6 CFM pump. About an hour after turning the pump on, it overheated and shut off.

    My bag had a very small leak in it that I couldn't find but I've decided to get a continuous duty pump. I'm looking at the gast pumps and welch pumps and the variety of pumps available is staggering. Ultimately, I will be bagging a 17-ft hull so I need a pump that can handle a bag setup of this size.

    This one will develop around 27.6 in. of Hg and and will move 7 cfm:
    WELCH-THOMAS 2585B-50 DRY VACUUM PUMP

    The welch duo seal pumps look good too, although it doesn't look like they move as many cfm.

    Then there's the gast pumps. There's so many gast models I'm not sure where to start. The gast 6hCA looks more than capable but it's a piston pump and it looks like rotary vane pumps are more popular for whatever reason.

    Any guidance would be greatly appreciated. My budget is $800.
     
  2. KnottyBuoyz
    Joined: Jul 2006
    Posts: 829
    Likes: 55, Points: 0, Legacy Rep: 685
    Location: Iroquois, Ontario

    KnottyBuoyz Provocateur & Raconteur

    I think your Robinair will do the job. Two issues, heat and continuous service. If you can resolve either you won't need a new pump. Heat: Get rid of it, setup a small fan to blow on the cooling fins of the pump. Running Continuously: Stop that. Find the leaks and seal them.

    I found a way to cycle my Robinair automatically at joewoodworker.com

    We've discussed this before.

    http://www.boatdesign.net/forums/fiberglass-composite-boat-building/infusion-pump-33015.html

    http://www.boatdesign.net/forums/fiberglass-composite-boat-building/vacuum-pump-size-20419-2.html

    If you're moving your project into a full blown production environment the investment in better pumps is essential. If this is a one-off project I'd save my $800 for fitting out the boat.

    As much as I'd love to have a gizmo like the Accutrak VPE 1000 I've had pretty good success with my $3 Spy Ear finding leaks.

    http://cgi.ebay.com/SPY-EAR-VOICE-A...739?pt=LH_DefaultDomain_0&hash=item4aa97187cb

    Good luck with your project.
     
  3. weldandglass
    Joined: May 2010
    Posts: 23
    Likes: 0, Points: 1, Legacy Rep: 10
    Location: Gulf Coast of Texas

    weldandglass Junior Member

    Knotty:
    Thanks very much. I had read the threads you referenced but when I started looking at pumps I still had a lot of questions. I spent some time reading yesterday and finally ended up ordering a Gast rotary vane 3/4 HP pump. I hope it will fit the bill.

    I understand that any pump is working harder if it has to run continuously and as such, I need to make sure I'm getting a good bag setup. However, I want the pump to be able to handle the load if I can't find/stop all of the leaks. Hopefully the Gast I ordered will have no problem fitting this bill.

    I appreciate the response very much.
     
Loading...
Similar Threads
  1. frenette
    Replies:
    3
    Views:
    2,692
  2. abosely
    Replies:
    19
    Views:
    6,507
  3. Tungsten
    Replies:
    5
    Views:
    1,778
  4. JRD
    Replies:
    6
    Views:
    2,369
  5. WHumphreys
    Replies:
    17
    Views:
    11,579
  6. James Mills
    Replies:
    21
    Views:
    18,449
  7. Pjitty
    Replies:
    104
    Views:
    29,037
  8. GreenFreak
    Replies:
    12
    Views:
    450
  9. Dejay
    Replies:
    44
    Views:
    3,305
  10. KD8NPB
    Replies:
    8
    Views:
    869
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.