installing transducers on aluminum hulls

Discussion in 'Boat Design' started by Jwil, Sep 10, 2014.

  1. Jwil
    Joined: Sep 2014
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    Jwil New Member

    New boat and I need to install a transducer on aluminum hull, I was told about 5200 and then read it was for fiberglass and wood hulls. Any one with insight that can help would be much appreciated.
    John
     
  2. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Where do you want to mount the transducer? 3M-5200 is a sealant/adhesive, with very tenacious adhesive properties, but shouldn't be confused with a dedicated glue. It's best used as a bedding, that needs to offer some adhesive aspects to the joint, rather then an adhesive that has some sealant ability.
     
  3. Tungsten
    Joined: Nov 2011
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    Tungsten Senior Member

    What? Your saying you can put your fish finder transducer on the inside of an aluminum boat?
     
  4. Jwil
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    Jwil New Member

    no I will be mounting on outside lower transom, boat is a tunnel so I did not know if the 5200 would be best for adhesion and water proofing abilities, or if just silicon was better.
     
  5. PAR
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    PAR Yacht Designer/Builder

    Don't use silicon anywhere on the boat, except to mount glass in a frame. Other wise you'll regret is employment on anything else. What type of mount will you use. Typically the transducer's bracket is screwed to the hull, over a bedding. 3M-5200 works well for this, but I'd use something softer and more flexible, like SikaFlex 291. If you want to bond the bracket, I'd use epoxy, instead of goo in a tube.
     
  6. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Yes you can!

    Of course there is some attenuation, but the average fish finder has a range of 500 ft or more, so that is no real problem.
    Find a piece of aluminum or grp tube large enough to hold the transducer and bond it to the bottom with epoxy. Mount the (through hull) transducer in a plastic cap and place it on the tube after you've poured enough oil or brake fluid in the tube so the transducer will be submerged completely.
    Keep the lid in place with some silicone or tape.
     
  7. Tungsten
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    Tungsten Senior Member

    Thanks,you said ". Mount the (through hull) transducer" does this mean theres a special one for this?Or the one I have will work?
     
  8. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Through hull transducers are easier to install in a single mounting hole, but you can also use any other type with the transom bracket removed if you can attach it firmly to the tube or the lid.
     
  9. whitepointer23

    whitepointer23 Previous Member

    they don't do that now cdk. Most transducers are simply pushed onto a bed of epoxy directly on the hull. You mix the epoxy nice and slow so it doesn't trap air bubbles. It's a good idea to try the transducer where you want it and then hang it over the side and try it again. Compare the 2 readings to make sure it works in the boat before gluing it down.
     
  10. CDK
    Joined: Aug 2007
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    CDK retired engineer

    That would be even better for the transmission quality if you succeed in doing it without a big air bubble in the center. I would be afraid I'd have to chisel the thing off if the range was just a few feet.
     
  11. whitepointer23

    whitepointer23 Previous Member

    The first time I saw a transducer glued direct to the hull I thought the installer had made a mistake . But then I found the method detailed in an eagle fishfinder manual. Its like with the old sounders you had to bundle the transducer lead if it was to long. Now you can cut them shorter or add extensions. Is it because the new ones are digital ?.
     
  12. CDK
    Joined: Aug 2007
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    CDK retired engineer

    We were all obedient, nobody cut the cable of a "Seafarer" depth sounder because the manual told you not to do that.
    I did it accidentally when removing some excess wiring, thinking it was a loudspeaker cable. It turned out to make no difference whatsoever, except that years later water intruded there and ruined the cable.
    Modern fish finders shout louder and listen better, so cable losses are less important.
     

  13. whitepointer23

    whitepointer23 Previous Member

    I have been looking at the latest lowrance and garmin sounders to fit in my boat. They are amazing machines . The salesman I spoke to had just come back from a trip in Queensland on the garmin company boat. He was taught how to use all the features. With down scan individual king pawn under the boat were visible on the screen. Pretty good for a fishfinder that sells for under $1000 dollars
     
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