Transponder/transducer thing pointing the wrong way?

Murv

Murv

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Our first boat is now out of the water.
One thing I noticed is that the transponder/transducer for the fishfinder points the wrong way.
It can be easily swiveled back down but, obviously, not once it's back in.
Can I just unscrew the thing and move it up slightly so that the water force won't push it round the wrong way? can I just drill new holes to do this? do I fill the old ones if I do, if so, what with? will we sink if I don't?

IMAG0092.jpg
 
The way it is pointing is correct.
There should be a line on the centre of the transducer which should be aligned with the bottom of the hull.
 
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That looks like a bit of a half-a4sed way to fit a transducer. How does the cable come through the hull? Not with a great blob of silicone sealant I hope.

It is a transon transducer and is not meant to be completely immersed. Lots of us have them and we keep them inside out of the water, with no holes through the hull. Simply stuck to the hull at a suitable place (with a blob of silicone in my case.) You must ensure that the blob is free of air bubbles. There have been several threads on how to fit transom mount transducers inside the hull.

There is no noticeable loss in efficiency. Mine gives readings to well over 200 feet and has gone over 300 on occasions. My echosounder (with a through-hull transducer) rarely reads in depths over 60 feet.

EDIT Ah, I see that it IS on a transom. I take it all back, but I still think it would be better inside. I cannot see how it got to that position anyway. It looks the same as mine and the top surface is where the cable enters. (I think BERT T is wrong). To reposition it, the two bolts holding the bracket should be released and the bracket turned 180 degrees.
 
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Superb, thanks for that.
The cable doesn't actually exit the hull at all, it just lies over the top of the transom.
Apologies for my confusion, I had assumed it was meant to point downwards.
Will search for threads on internal mounting it, it would certainly be neater if inside the boat.
 
It looks to me like it has been mounted upside down but you should google the make and model to confirm that. It has a hinge so that the transponder part can pivot up out of the way to prevent damage during trailoring or if it happens to catch on something while in the water. They are normally mounted so that they sit flush with the bottom of the boat and at a distance from the prop as required by the fitting instructions. To change it round just undo the hinge nuts rather than messing with the bracket mounting that is screwed to the transom.

transducerMountingCloseUp.jpg


I believe that this transponder is only designed to work while mounted on the transom so I don't think it is possible to mount it inside the boat and have it work but hey, Wight Dawn says he knows a way to do so... it sounds like it worked for him. To my mind, if that's what ya want, why not just buy the correct type of transducer :-)
 
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Ye've got it on upside down!

Take out the bolt that runs through the middle, turn the transducer over, and put the bolt back in again. The transducer should be below the bracket, with the rounded end facing forwards.

Pete
 
Murv said:
Superb, thanks for that.
The cable doesn't actually exit the hull at all, it just lies over the top of the transom.
Apologies for my confusion, I had assumed it was meant to point downwards.
Will search for threads on internal mounting it, it would certainly be neater if inside the boat.
Click to expand...

I dont think that type of transducer can be mounted internally. Those that are mounted internally are either mounted in a tube of oil to make acoustic contact with the hull or stuck in position with sealant to do the same thing.

This http://www.fishfinderdiscounts.com/page/fishfindertransommount shows how your type should be mounted.
 
Thank you all.
Have googled the instructions now and yes, it is on upside down!
I don't think I'll be able to simply invert it as the bracket has been fixed to far down. If I invert it as it is, when the boar settles on the mud it will push the transponder up and out of position.
It can indeed be mounted internally (sand the top and mount it on epoxy) although the manufacturer does warn that it will lose sensitivity.

I think it may be the best option though, if nothing else it will make things neater by removing the cable that's trailing over the transom.
Googling suggests that the remaining holes are easily filled with epoxy so will see what is available and what will give me a reliable repair in lower temperatures.
Or, I may be able to modify the bracket to hold the transducer a little higher up

Seems the last owner had a bit of a thing about mounting things upside down, the trim tab switches operate back to front and upside down!
It's an easy fix by rotating the switch plate through 180 degrees, just seems a little odd!
 
Murv said:
Thank you all.
.... I think it may be the best option though, if nothing else it will make things neater by removing the cable that's trailing over the transom.
Googling suggests that the remaining holes are easily filled with epoxy so will see what is available and what will give me a reliable repair in lower temperatures.
Or, I may be able to modify the bracket to hold the transducer a little higher up
Click to expand...

I would practice with holes above the water line before having a go at those below. Ideally to do a decent job you need access to the inside of the transom as it is likely that the screws have gone all the way through.
 
West Systems do an epoxy repair pack for about £15-20.
Make sure everything is clean and dry using some acetone, mix up some epoxy and "wet" out the drill holes to repair, thicken the remainder epoxy with some fillers (in the repair pack) and fill the holes.
When hardened, sand the repair down a mm or so, and cover with some gel.
Gel will bond to epoxy but the epoxy MUST be fully set, and here I mean weeks or alot of warming in winter.
If you can spread butter on your toast, you can do this job !
 
quick fix

Hi for a quick fix i would undo the bolt that it hinges on and turn it the right way up,then get two strips of stainless strips approx 2" long with holes at each end you can get these from most chandlerys,i think thay are for dingys
then you can hinge it up to the height you wish for
the end that is fixed to the boat i woud use two nuts@bolts
 
When I bought a Raymarine Plotter, with a fishfinder, it came with a transom mount transducer. I just sawed off all the mounting lugs, and installed it in-hull. I cut a short piece of plastic drainpipe, at an angle to suit the bottom of the boat, and using that for "shuttering", bedded the transducer in resin. Works perfectly.
 
Thanks all, I appreciate the help :)
I think, logically, that it must be OK. I mean, surely it wouldn't have been on there all that time the wrong way up, it would permanently read <1' of water!
I imagine what he's done is mounted the bracket upside down, maybe to stop it keep knocking the transducer out of position when it settled briefly on the mud in it's original location.
 
Mount internally

I just bought Garmins cheapest Fishfinder complete with transom mount similar to the one on the Original Post.
I grabbed a jar of vaseline and stick the transducer on the inside of the hull as far forward as i had access for.
Hull is 8 mm Glass and Epoxy coated Ply.
Went out sailing for the weekend. Turned it on. It worked and continued to do so at all angles of heel and boat speeds. (I will mount it in silicone now i know it works in that location)
Cross checked with lead line etc and all good.

Complete unit with transducer was NZ$120 new = 62 squids.
So i was well pleased:) until the depth alarm went off 1 kilometer off shore.
Sure enough there is a new sand bank there.
Didnt hit it but now after sailing for years without a depth sounder of any sort I am scared to turn the thing off!:eek:
 
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