Mounting a transducer

Discussion in 'LOCAL OKLAHOMA TALK' started by mudcreeker, Jun 17, 2009.

  1. mudcreeker

    mudcreeker New Member

    Messages:
    94
    State:
    Antlers, OK
    I've got a technical question maybe someone can help me with....

    I've got a Grizzly 1648 aluminum boat and I am wanting to mount the transducer on the transom. However, I am a bit leary about drilling holes below the waterline on the transom. Currently, I only have a trolling motor on the boat, but in the future I plan on putting a small outboard motor on. Reading through some threads, I saw some suggestions of taking a block of wood/marine plastic/plastic cutting board etc. and using epoxy to secure it to the outside of the transom, then screwing the transducer onto it. This would eliminate drilling holes into the aluminum. Does this sound like a good idea? Would epoxy bond strong enough to hold the wood to the aluminum? Any suggestions on what kind of epoxy to use? There was also mention of C-clamping the wood onto the transom, but I didn't think that was aesthetically pleasing as epoxying a small block toward the bottom, the same size as the mounting bracket.

    Any other ideas? Any help would be greatly appreciated!
     
  2. drpepper

    drpepper New Member

    Messages:
    6,133
    State:
    Indiana
    no way I'd do the epoxy/plastic thing for a bunch of reasons. cavatation and it falling off are the main ones.
    Drill the holes and seal the screws... it won't hurt a thing.
    figure out the best place for it... away from the motor, between strakes, so far down. etc.
     

  3. mudcreeker

    mudcreeker New Member

    Messages:
    94
    State:
    Antlers, OK
    OK... what is best to seal with? And do you put the sealant on after it is screwed in, before or both?
     
  4. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    3M 4200.
    3M 5200 would hold a block of plastic to the hull.

    If it were me I would mount a block say 12-14" inches long.
    You could mount multiples on it or have room to adjust your transducer to overcome a turbulence issue or bubble issue. Seen some of these blocks that were slotted the entire length.
     
  5. drpepper

    drpepper New Member

    Messages:
    6,133
    State:
    Indiana
    yeah turbulance/bubbles is what I was thinking when I said Cavatation. thats what I thought a plastic block would cause.... (turbulance/bubbles) Markj is the boat tech though so....
    It just seems to me a "plastic block" would be way more hassle and problamatic than just mounting directly and sealing the screws. Alot eaisier if you ever wanted that stuff off- or made a mistake in where you located it. I still think directly is best. JMO. and mark says 3m 4200 to seal it with.

    do you you have to do anything to prep the surfaces for the 3M 5200?
     
  6. mudcreeker

    mudcreeker New Member

    Messages:
    94
    State:
    Antlers, OK

    How strong is that epoxy? Can I use that alone with no screws securing the block to the boat?
     
  7. SkipEye

    SkipEye Well-Known Member

    Messages:
    7,525
    State:
    Winfield, MO
    Name:
    Darryl
    Why risk it falling off?????

    Holes are no big deal if sealed properly. I'd mount the marine plastic (starboard it's called) with screws to the transom. Seal the screwholes and the back of the board with 3M 5200 and you'll never have to worry about it. Then you can move your transducer as many times as you wish or mount other accessories with no new penetrating holes.

    The first hole is the hardest. After that it becomes easy. Now go get your drill and don't worry about it so much.

    Look at the size hole your livewell pump has through the transom.:eek:oooh:
     
  8. mudcreeker

    mudcreeker New Member

    Messages:
    94
    State:
    Antlers, OK
    I guess I just need to quit being a sissy and take a drill to the boat! It is my first boat and I just don't want to screw it up....
     
  9. SkipEye

    SkipEye Well-Known Member

    Messages:
    7,525
    State:
    Winfield, MO
    Name:
    Darryl
    You'll be fine. Plan ahead, make sure of where you want your screw holes, check for obstructions etc. on the inside just as a precaution. You'll be fine, relax.

    We were ALL nervous our first time!:smile2:
     
  10. mudcreeker

    mudcreeker New Member

    Messages:
    94
    State:
    Antlers, OK
    Well I thank you much for your help!
     
  11. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Many times people have posted that they bought a boat and want to rod holders on it but dont want to drill a hole in the boat.

    I'll break it down real simple.
    Why did they even buy a boat if they can't use it like they want to?

    A hole doesn't destroy a boat. The man holding the drill might though.:big_smile:

    Look at it like this. I've never run into a hole that couldn't be repaired or patched.

    On an aluminum boat the biggest worry you have is contact between disimilar metals. One big reason I don't care for aluminum boats. It's so limiting in the hardware you can use that is available for wood or glass boats.
    You miss out on alot hardware wise and quality hardware.
    I wouldn't use stainless screws.

    Let me tell ya. If I spent the money some folks do on buying boats I wouldn't hesitate to put a drill to it. I'd get my money's worth out of it. That boat isn't going to make you any money when you sell it anyway.

    Drilling holes in wood or glass boats is handled a little differently.
    You want to drill your holes oversized by 2 sizes. Fill the holes back up with epoxy with some cabosil mixed in it. Then redrill the proper sized hole in the middle of that plug.
     
  12. lendog

    lendog New Member

    Messages:
    2,141
    State:
    berks, PA
    i've always just used some type of wateproof calk and haven't sunk yet:eek:oooh:
     
  13. SkipEye

    SkipEye Well-Known Member

    Messages:
    7,525
    State:
    Winfield, MO
    Name:
    Darryl
    Why would there be a problem using stainless hardware. It's used in the marine industry all over the place for numerous applications. Stainless is a compatible metal to be used with aluminum. I haven't seen any problems.
     
  14. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    Stainless and aluminum aren't compatible metals.

    Don't look at the marine industry especially boat manufacturers as proof of anything.
    I've seen too much S**T from alot of them. Downright wrong and know it's wrong stuff.

    Stainless and aluminum put together in a dry stable climate or atmosphere would stand a better chace but it would still be a problem.

    That is the primary reason I'm not a fan of aluminum and boats.:wink:
     
  15. SkipEye

    SkipEye Well-Known Member

    Messages:
    7,525
    State:
    Winfield, MO
    Name:
    Darryl

    Ok....now that I have looked it seems Aluminum and SST are pretty far apart on the galvanic table. So........What should we be using Mr. Mark?:confused2:
     
  16. Mark J

    Mark J New Member

    Messages:
    9,407
    State:
    Four Oaks, NC
    It's really more complicated then just the type of metal alone.
    Any two different types of metal put together will cause galvanic corrosion.
    One metal is going to take the beating.

    You are also dealing with mass.

    A better choice considering the mass of the boat itself would be zinc plated.
    The zinc plating would be the sacrificial anode rather then the boat.

    Stainless would be ok but with long term problems in a dry enviroment. In a wet enviroment the boat will be the sacrificial anode.

    Cadmium coated is a good option but probally not practical and it's also environmentally unsound.

    It's not only the fastener that is of concern it is also what you are fastening to the aluminum. You may need to isolate the metals with a gasket of some sort.
    You'll notice some cleats come with a rubber gasket or rubber boots for that purpose.

    It still boils down to what you are willing to sacrifice. A screw or the boat.
    One or the other is going to be sacrificial.

    It's really a pretty tough question you are asking. Aluminum is just not a durable metal in regards to galvanic corrosion. There really is no perfect solution other then aluminum fastenings however some choices are better then others.
    I would be looking at coated fasteners of some sort if an aluminum fastener wasn't practical.
     
  17. riverbud55

    riverbud55 Well-Known Member

    Messages:
    2,932
    State:
    AZ Topock-/CA Riverside
    Name:
    Dale Miller
    ya mite think of welding on a bent bracket like the one's that came on my North River , if ya got to put something on it different later on ya haven't got a problem with the old holes:wink:
     

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