fishfinder

[Guest]

Got a 6.5 m outboard equiped motor boat and need to fit a transducer to the transom. Anyone got any ideas how to fix it on without paying the high cost of a lift out?

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[dickh]

Get several friends to sit on the bows to raise the stern(keep them there with a crate of beer). Secure to berth with several lines so the boat doesn't move much, then either work from pontoon or from a dinghy lashed alongside. Drill/secure transducer to hull using recommended method as in the instructions.
DON'T use a mains voltage drill, only a portable 12 volt type.
Then relax with your friends in cockpit consuming the rest of the beer, patting youself on the back at saving the lift out charge.

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[gjgm]

which fishfinder/transducer? Most transducers work fine fitted inside the hull. Best is to use slow epoxy, but note it is very runny..You must avoid any air bubbles in the glue. Next "upgrade" is the sit the transducer in a couple of inches of drainpipe to form a bath, and fill with a mineral oil. Test the site of fixing before glueing to make sure you get a good reading.Some some say you can use (less permanent) silicone. I gave up with transom mounting as couldnt get constant reading across speed range (but thats up to 50mph), but works fine using above method. PM me if you want any more info

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[Guest]

Thanks dickh and gjgm.
I can imagine the scene at the marina with half a dozen drunks trying to get the bow down! Will try the beer bit it if desperate. The stern might just come up the the 9 inches I require.
The set is a Garmin 160 blue with dual freq transducer that has a speed sensor added (just a paddle wheel really). When Ive looked at other boats with sensors fitted to the transom they all look really fouled up. Cant imagine they work that well in this state.
I like the idea of epoxying it in though. Have checked the boat manufacturers bumpf to see if there is a spot on the hull spec for transducers but no joy. I presume the mineral oil bit is to test the installation first before epoxying it all in. Am I right here?
Cheers

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[gjgm]

you dont give any boat details under your profile....Basically anywhere on the inside of the hull near the centre line and that is likely to have clean flowing water underneath, probably towards the stern., maybe a foot or two forward.If you have a stepped hull, it will need to be in front of the step, so that might be 1/3 of the length of the boat forward. Advantage of using silicone is that you can (probably) move the transducer if the reading is disturbed,although some say dont use it because it acts as a barrier. Problem with epoxy is once its glued, its not moving again! So idea is to make a watertight bath out of some pipe, add some water and weight the transducer down in order to test the siting. In practice, it can be a bit fiddly to get the bath watertight, but at least nothing is permanently glued at this stage. Once you have tested across your speed range, and found a good location,you can epoxy the transducer into place. Best practice is to then make the bath again, and fill with oil (although water also seems ok), and then you should have a perfect display. Temp should work too (although strictly it is of the hull, not the water). If you go to garmins web sight, there are probably some tips... But all in all its pretty easy, just dont glue it permanently somewhere that doesnt work !

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[gary_yank]

Re: fishfinder, locating the glue site

I have done about a dozen, 'glue in' mountings.

Get a plastic bag and fill it with water and put the transducer in to it. Slightly dampen the outside of the bag and place the bag in the locations where you would like the transducer, when you find the location that gives a true reading, minus the depth of the hull at that location, mark it.

Sand the area and the bottom of the tranducer with an 80 grit paper to remove paint and give texture for the glue. DEGREASE THE AREA and while glueing insure than no air bubbles are in the epoxy or under the tranducer. Often a dam of silicone or clay can be used to create a leveled glue surface so that the transducer shoots straight down rather than at an angle.

Gary


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[Guest]

Re: fishfinder, locating the glue site

Thanks for all the info guys. Does the transducer have to sit in mineral oil or water to work then?

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[gary_yank]

Re: fishfinder, locating the glue site

Only while you are finding a location if you are going with the epoxy method, unless you are going the pipe and mineral oil route then yes it must be in the oil.

If your boat is double hulled or if you have a laminated core in the boat then a through hull or transom mount is easier.

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[Dave_Knowles]

Re: fishfinder, locating the glue site

How about mounting the transducer on a piece of hard wood about the depth of the transom then lowering it over the back and fix the wood to the transom using a couple of bolts or screws abvove the water line. In that way you can always take it off for cleaning at any time without having to take the boat out.


<hr width=100% size=1>Take care.

Dave

Dave Knowles
Southampton - UK

http://www.MyCleopatra.co.uk