Transom Mount

[QuickMick]

I just got a hummingbird fish finder, which can be mounted thru hull or on transom. I am going to opt for the latter. Now I am loath to poke a hole in my boat (just seems counterintuitive, lol), is it possible for me to mount the transducer while she is in the water? I was planning on pulling up to the hull in a john boat and mounting the bracket just above the waterline provided the trans.d will hang down far enough. Does anyone have experience with this type of mounting, and/or know how far below the water that baby needs to be? all the installation info seems geared toward bass boats on trailers.

thanks much

[mitiempo]

Quinn
You can epoxy it to the hull inside and it will work well. Take a plastic baggie full of water and try it by holding the transducer against the baggie in various places inside the hull. The best place is centerline forward of the keel, probably under the V-berth. Instructions are on both Humminbird's and West systems sites.

[BarryL]

Hello,

More than likely you can use the transducer inside the boat in 'shoot thru' mode. As mentioned, place the xducer inside a bag of water and try it in various places. I like mine as far forward as possible so I know of know the depth of water ahead of me.

Anyway, once you find a location that works, you can use epoxy, or you can use toilet bowl wax. I heard of the wax and tried it, figuring I would epoxy it down later. 3 years later the wax is working fine.

Good luck,
Barry

[JeffBurright]

Bear in mind that the inside hull mount doesn't work on wooden boats. I have a composite wood/epoxy/glass hull and it can't read squat through it.

Being that I didn't want to stick a plastic puck on my nice wood transom, I opted for the slightly irresponsible approach and ran the wiring through one of my rear cockpit drains, using tension on the wire to hold it at the correct angle. I'll probably have to take it back out before going on the ocean, but it works well in lakes.

[sailingdog]

Not only won't this work on a wooden boat, but it won't work on any boat with a cored hull. I'm also not a big fan of epoxying anything that might need replacement to the boat.

One way to install one on a solid fiberglass hull boat is to glass a PVC pipe into the hull and mount the transducer into the pipe and fill the pipe with mineral oil.

[QUOTE=mitiempo;579009]Quinn
You can epoxy it to the hull inside and it will work well. Take a plastic baggie full of water and try it by holding the transducer against the baggie in various places inside the hull. The best place is centerline forward of

[sailbot]

If ya mount it to the Transome , be aware that any turbulance geneated by the transom and rudder r going to mess up your readings, the transducer maust be mounted in non bubblely water to work right

[QuickMick]

thanks for the feedback. I did some testing, and it seems to cop a good reading in the engine compartment--if the fact that the hummingbirds depth reading matches the reading on my bulkhead mount depth sounder. Good to know that my bulkhead mount is reading from the hull, not the keel!

oddly, i wasnt tracking well setting it on the hull, yet in the baggie of water she was right as rain. now im concerned about epoxy-ing it to hull due to this discrepancy....

[mitiempo]

Quinn
What do you mean it "wasn't tracking well set on the hull?" Without the bag of water it shouldn't work. If it works with the baggie in a place you would like to install it clean and sand the hull a bit and epoxy it in place.
Using epoxy is the simplest most trouble free way to attach it. Zero maintenance. Transducers aren't repairable only replaceable. When if ever the time comes to remove it a good whack sideways will do it.

[svHyLyte]

When one epoxy's a transducer to a hull one increases that mass that must be vibrated by the face of transducer head, which reduces it's effectiveness. An alternative that prevents that and is a relatively easy installation is to obtain a very short length of 4" diameter PVC pipe with an end-cap with a threaded plug slightly larger than the transducer head from Lowes/Home Depost or where ever. Shape the open end of the pipe to match the inside of the hull and then fix that in place with a good bead of 3M 4200 adhesive. Once that has set up, fill with mineral oil to a depth sufficent to completely cover the transducer head when the cap is screwed in place (you will need a small "breather" hole in the cap but that can be plugged with a dot of 4200 after you have topped off the pipe with oil). The foregoing actually takes longer to describe than do but it makes for a neat effective installation--on a solid hull--that provides easy access for the replacement of the transducer should that ever prove necessary and can be entirely removed without harm to the hull if necessary (hence the 4200 verses more tenacious 5200).

FWIW...

[sailingdog]

This is a variation on what I basically recommend. I generally use a clean out fitting and use the cleanout cap for the transducer mount. That way the PVC can stay fiberglased to the hull and still allow you to remove the transducer.

Originally Posted by svHyLyte

When one epoxy's a transducer to a hull one increases that mass that must be vibrated by the face of transducer head, which reduces it's effectiveness. An alternative that prevents that and is a relatively easy installation is to obtain a very short length of 4" diameter PVC pipe with an end-cap with a threaded plug slightly larger than the transducer head from Lowes/Home Depost or where ever. Shape the open end of the pipe to match the inside of the hull and then fix that in place with a good bead of 3M 4200 adhesive. Once that has set up, fill with mineral oil to a depth sufficent to completely cover the transducer head when the cap is screwed in place (you will need a small "breather" hole in the cap but that can be plugged with a dot of 4200 after you have topped off the pipe with oil). The foregoing actually takes longer to describe than do but it makes for a neat effective installation--on a solid hull--that provides easy access for the replacement of the transducer should that ever prove necessary and can be entirely removed without harm to the hull if necessary (hence the 4200 verses more tenacious 5200).

FWIW...