Bilge pump float switches

Discussion in 'All Things Boats & Boating' started by Frosty, Nov 20, 2012.

  1. Frosty

    Frosty Previous Member

    Dont under any circumstances buy TMC flaot switch they have a ball in them and fail in weeks.

    TMC electric toilets are brilliant and have lasted me 10 years and still going strong.

    MY Rule shower bilge failed, it would pump but not clear water !!! This had me stumped as I use in all stations Robinson 1250 with rule switches.

    I cut the switch in half and could not find anything --I had news paper on the bench to catch mercury --I had to cut it to tiny peices to find the thing what did it.

    It was a thing the size of a bullet and thats all it was in the whole plastic moulding --if it had grated cheese it would have been in the 99 cent shop.

    The mercury was self contained and could not be accessed ( whats all the fuss about) It turns out the sw wire had rotted inside yet not wet and only one strand of wire was left feeding the pump allowing it to work but not hard enough and it had little head.

    Off I went to the shop and gasped at the price of the new mercury free switches so I bought a Seapro made in china, looked the same , half price--mercury free and clicked up and down--obviously a micro switch.

    Long story short ---worked well for 10 days then failed badly leaving the pump running= dangerous.....

    Could not get my money back even after just 10 days so bought a Rule that ---blow me was the same with a clicking sound on operation. I am assuming the Rule made in Porto Rico is better made that Seapro made in China I hope.

    What is it with this marine crap its getting worse ---10 days no warranty. And whats this scare mongering about mercury!--- it is concealed in a very tiny yet solid steel case.
  2. keysdisease
    Joined: Mar 2006
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    keysdisease Senior Member

    Mercury is one of the most dangerous neurotoxins on the planet. The term "mad hatter" has roots in the days when hat makers used mercury to form felt.

    Aside from that mercury does not play well with aluminum at all so it should be very carefully considered if one is buying a switch for an AL boat.

    You noted the workmanship of the switches you bought, how well sealed is that encasement?

  3. Frosty

    Frosty Previous Member

    I used to play with Mercury at school . So did the rest of the class. It was funny stuff that was very heavy and would roll a round in the palm of your hand and tickle because of its weight. If it dropped on the floor it splaltterd into many many globules that was difficult to find . I would steal little bits and keep it in my fountain pen cap.

    I don't remember any one dying,---

    The Mercury is in a hard steel shell you would have to hacksaw it to get at it.

    The plastic case was dry, the failure was the wires.

    If I take the mercury switch and piggy backed it to another float it would still work even though it was in an external configuration

    Mercury switches seem to be the best by far.
  4. marshmat
    Joined: Apr 2005
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    marshmat Senior Member

    Mercury doesn't kill you outright until you get to rather large concentrations.

    In even trace amounts, though, it causes neurological damage. It messes with your higher cognitive functions and memory, and reduces your attention span, language ability and fine motor skills. With enough exposure, it'll cause nervous twitches, weird tingling sensations, emotional instability and severe cognitive impairment.

    So no, you don't want mercury in any place where people could, conceivably, be exposed to it.

    For a bilge pump switch, a better option is a float on a vertically sliding rod mounted to a bulkhead, with a microswitch at the top (well above the water).
  5. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    Crappy marine engineering is nothing to worry about. Switches/ sensors/ alarms fail all the time and nothing bad happens.
  6. midnitmike
    Joined: Apr 2012
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    midnitmike Senior Member

    I see some simularities to another thread. It's made out of plastic, lasted for ten years..this doesn't happen to belong to a friend?

    On another note I gave up on bilge pump switches back in the 70's. The poor choice of materials, the unreliability, and the danger that comes from an unexpected failure led me to take a more hands on approach. I never take my safety for granted. While such devices can provide some measure of forewarning or safety, I've seen far too many instances where this often lulls the user into a false sense of security. But hey you're a gambler so why not rebuild this switch in your own image...I'm sure it will work better then the factory model.

  7. waikikin
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    waikikin Senior Member

    Frosty, time to build your own........ out of 100mm PVC. Jeff.
  8. Tynesider
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    Tynesider Junior Member

  9. SamSam
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    Location: Coastal Georgia

    SamSam Senior Member
  10. Frosty

    Frosty Previous Member

    Yes 10 years --its the same boat all fitted when the boat was built.

    I dont understand this "why bother with a float switch" Its a 44footer thats in left in the sea not on a trailer boat. There is 6 1250 pumps all together all on Auto stand by with LED.

    How do you configure a shower sump without an auto sw?

    Yes its time to make one of my own but 100mm DWV PVC is a bit overkill.

    The ping pong ball Idea will be considerd and yea it will far exceed the quality of the 10 life of the Seaflo which uses a micro switch too--good idea.
  11. michael pierzga
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    michael pierzga Senior Member

    Jabsco Air pressure bilge level sensors last forever and never fail.

    Make your own from PVC pipe left over from your exhaust experiment, plus a pressure switch, or purchase the Jabsco complete.

    Longer PVC cups prevent bilge slops from entering the air tube and make mounting and service easier.

    The electric working capacity of the switch output must be in relation to the size, current draw, of the pump or when the switch triggers the dc pump the sensor switch will burn out.

    The Jabsco is 6 amp, hence only a small pump can be used . A larger pump would require a relay. .... Hence Bilge Sensor turns on relay, relay turns on pump.
  12. waikikin
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    waikikin Senior Member

    50mm?, a 6M length could be a life time supply. Just about to use some PVC conduit to support some hawke seagull deterents above some pontoons, you can do a lot with these products, even some they're designed for! Jeff.
  13. watchkeeper

    watchkeeper Previous Member

    Frosty, you were lucky to get 10days worth - Chinese made marine goods are not worth the risk
  14. taniwha
    Joined: Sep 2003
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    taniwha Senior Member

    I have always wondered what was wrong with Frosty now at least I know :p

  15. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    I saw a site where a few guys recommended washing machine pressure switches, but I don't know if they were sensitive enough for shallow amounts of water.
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