Dead heading a rubber impeller bronze wash pump?

Discussion in 'All Things Boats & Boating' started by sdowney717, May 18, 2015.

  1. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    I have a Jabsco utility pump and I put in a Globe impeller.
    I have a well pump switch but the thing is it corrodes in the salt water so the pump wont turn off when the hose turns off. I will take it apart and maybe get it functional again.

    So was wondering about simply turning it on with the output flow blocked, would that cause a problem? Seems the impeller vanes just would bend out of the way. The Globe impeller uses a more slippery type rubber than Jabsco.

    Not that it would run that way all the time although I want it to just turn off and on with demand like before. So is there a pressure switch idea that could continue to work in salt water?
     
  2. philSweet
    Joined: May 2008
    Posts: 2,410
    Likes: 237, Points: 63, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

  3. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

  4. philSweet
    Joined: May 2008
    Posts: 2,410
    Likes: 237, Points: 63, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    What valve? What is a well switch? I haven't a clue what you are talking about. Can you post a schematic? A description of how you use it? Hours, flow rate, pressures, line sizes?

    You'd probably get more people taking the time to respond if you took the time to explain what your system is and what it needs to do. I don't know if this is a deck wash down on a commercial fish boat that gets used 20 hour a day in season or something to wash sand off your feet when you come aboard. Is $1000 not a reasonable price? What would be? There are some decent little pressure switches made by GEM. About $400 if I remember. You could call pump people and buy a replacement pressure switch, but it doesn't help by itself. You either need a bubble tank and a convention pressure demand switch like that in every home well system in the country, or you need an electronic controller like on the pump I provided the link to. You can't just run a simple switch, at least not for very long, the pump will short cycle. Some very cheap rv supply pumps do this. But they are an integrated design and designed to operate this way. I wouldn't want to do that to a regular pump designed for a float switch or whatever.
     
  5. AndySGray
    Joined: Jun 2014
    Posts: 296
    Likes: 13, Points: 18, Legacy Rep: 91
    Location: Cayman

    AndySGray Senior Member

    The common ones round here are the 'Square D pumptrol' and are about 15 bucks in most hardware stores.

    The usual mode of failure is the contacts oxidising through sparks as they open and close.

    It is in the wrong position if you're getting water up the pressure pipe - they are designed to have an air pocket above the water, move it higher and put a longer piece of pipe on - pipe faces down - the picture below is on its side.

    Alternatively - the diaphragm which operates it has a plated steel housing/chamber held on with 6 screws - a good machine shop will be able to make you a brass or bronze version in a jiffy.

    [​IMG]
     
  6. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    Yes, my switch is very similar. My idea is to plate the chamber myself using silver brazing. Mine faces up and the pipe is 2 inches. I can put a longer pipe on there. It has likely rusted up so water pressure from the Jabsco pump can not push the diaphragm up to open the switch.
     
  7. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    I use a PVC check valve after the pump and before the switch, that way the Jabsco pump can pressurize the system, when you let go of the trigger handle on the water hose, the pressure left in the line pushes the diaphragm in the well pump switch and it open circuits the motor power. Then when you pull the water hose trigger to shoot water out the hose, the pressure drops and the well pump switch diaphragm drops down which turns on the switch and powers the jabsco pump again. This makes it an on demand pumping system, seawater flows when you want and the pump is off when you block the flow.
     
  8. philSweet
    Joined: May 2008
    Posts: 2,410
    Likes: 237, Points: 63, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    One other trick using the pumptrol style of switch. You can use a plug of thinnish food grade grease packed in a plastic tube to isolate the switch from the water. Not a game changer, but every little bit helps.

    There are waterproof and haz location versions of the standard switch. I'd use one of those.
     
  9. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    yes the grease idea has some merit.

    I took apart the entire switch, remarkably the problem was the plunger that presses the electrical switch open was rusted to the main housing, so it was always on. The water chamber area was ok. The only 2 things that are exposed to sea water are the rubber diaphram and black pipe threaded water chamber housing. The switch needs a cover, it is missing, I may just tape over with aluminum tape to seal out any possible water getting into top of the switch, which is why it may have failed.

    I decided to repair the switch. I cleaned all the rust off with Muriatic acid with a piece of copper pipe added in to coat the steel with copper. You basically make a 4 or 5 to 1 solution of water with acid, this is immersion copper plating.

    After It was all clean, I coated certains spots with clear epoxy, and then I coated the inner water chamber and rubber diaphragm with black Permatex silicone gasket maker. I will paint with rustoleum spray and then heat it in the oven at 170*F for an hour to cure on a hard finish. Then put it all back together.

    I did shorten an inner SS spring inside the electrical switch to let it turn off more easily, (clipped off one turn of coil on it's end, not showing that, it is under the electrical SS lever spring lever arm). There is that big spring, but I always had to run this switch with the big spring totally loose since the PSI output of the pump is not like a true well pump. This switch might have been a 40 to 60 psi pressure switch.

    Some pics, note the steel was very rusty, so it looks very pitted, but it was not too bad to fix and make function again.

    Also these are designed to run a 240vac pump, it is dual pole contacts. I plan to gang the poles together since the pump is only 120vac. That will half the current on each contact. The Jabsco pump draws 7 amps 120vac , so that mean each contact will then see only 3.5 amps.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]
     
  10. AndySGray
    Joined: Jun 2014
    Posts: 296
    Likes: 13, Points: 18, Legacy Rep: 91
    Location: Cayman

    AndySGray Senior Member

    Nice work.

    I've found the sealed electrical junction boxes to be useful for things like this...

    [​IMG]

    Though the screws need to be swapped for SS and some of the gaskets are an open cell foam so greasing the lid and using silicone instant gasket is often a better option in high humidity/ spray environs.

    You could drill holes for the 4 screws and one for the diaphragm and then sandwich with the cover on the outside and the mechanism and diaphragm inside...

    and use a waterproof gland for the cable.

    :)
     
    Last edited: May 26, 2015
  11. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    I found I had to adjust the pressure differential to get it to work reliably.
    That means adjusting the difference between cut off and cut on pressure. They typically are preset for 20psi. On mine a small center screw is turned to which a stop collar was soldered on to prevent people from adjusting to far. So I unsoldered that and got the pressure difference much tighter. Surprisingly there is a real head pressure in the hose that can affect that switch. I was finding if it worked to one level, it was not working at another height level as the differential pressure setting was too wide for that type of pump. This rubber impeller pump can not put out pressure like a true well pump. So if switch was set good for starting, it would not stop and vice versa.

    For my electrical connection box, I used a round zinc casting electric box I had here. I cleaned and painted it. I got a top cover plate to hold a plug socket, and the pressure switch turns the outlet off and on. The pump is plugged into that outlet.

    I have a manual off -on switch designed for wet locations, a sealed plastic box. It has a red push lever and that activates power to the pressure switch.
    That I mounted under the aft deck covering boards, so it is inconspicuous yet easily flipped off and on.

    I split the pump output after the pressure switch to two hoses. one for the boat general usage, the other is a 1/2 inch hose that runs through the bilge up to the anchor so you can wash off the mud.

    Another practical use for this pump is filling up my 10 gallon Lectrasan brine tank. I fill it with some solar salt and have switched from filling full with tap water to sea water. This brine tank allows the Lectrasan to work well when the flush water is not salty enough for the titanium electrode plates to draw enough current to sterilize head waste.

    I have read some people plumb sea water to their sinks for rinsing, anyone doing that?

    It may be that this switch got so rusty from when I first installed it and it sprayed salt water everywhere from a leaking pump seal. The switch design, if it gets wet, will catch some water in the little piston that sits above the rubber diaphragm. It was that piston that had rusted solid to the switch housing. What I need to do is make a cover for it, something like your showing. Such cover would have to accommodate the wires and the water pipe that feeds water to the switch.

    I suppose any future water pump leaky spray would get it all wet with salt water again.
     

  12. sdowney717
    Joined: Nov 2010
    Posts: 955
    Likes: 54, Points: 28, Legacy Rep: 274
    Location: Newport News VA

    sdowney717 Senior Member

    Here is a picture of the arrangement.
    I have it all working perfect right at the moment.

    Plastic PCV valve is first, that holds the pressure so switch wont run the pump unless you pull the trigger on the hose end sprayer.
    I covered switch with aluminum duct tape. Only reason some bronze and copper fittings are in this is I had them so why not use them instead of buying more plastic PVC. West marine had the white nylon adaptor for the grey hose. All the metal fittings are in excellent condition.
    Do it Best hardware had the 1/2 inch plastic female hose end, which was hard to find in 1/2 inch. That hose runs up to the bow.

    This pump is GFCI protected and it does not trip the GFCI unless I stick my fingers onto the inner switch connections, which I did accidently with it live. I have one GFCI for all the outlets, and one GFCI for the microwave. The outlet GFCI is somewhat modular wired with some sockets and plugs for wires that go to wetter locations. This way if something got wet and tripped the GFCI, I can unplug the circuit and reset the GFCI. Which I have not yet have had to do, no nuisance tripping. I use a commercial grade Hubbell GFCI outlet for all the outlets, which number about 10 spread throughout the boat.

    [​IMG]

    The pump. Cheap and good way to connect hose ends are these screw together ones sold at Walmart. They say for 5/8, but crank em down tighter and 3/4 works too, both 3/4 rubber and 3/4 garden hoses.

    The yellow breaker box is the gen breaker and I need to repaint, likely should also copper coat then coat with some epoxy the steel.
    [​IMG]

    To secure pump parts, I cut strips from plastic oil jugs and used SS screws, I found this to be effective and cheap.
     
Loading...
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.