# "Shootin" Through"



## hairymick (Oct 18, 2005)

Hi guys,

I bought a Garmin 140ff the other day and installed it in my ply yak.

First transducer install was in a piece of poly pipe that was siliconed to the bottom and transducer was mounted in it. The pipe was filled with water. It worked, but the readings were not strong and the picture on the screen was intermittent.

Next, I smeared silicone to the bottom of the yak and stuck the transducer down on it. There were no air bubbles and the installation was rock solid. This was even worse. The sounder would not read in depths under about 15 feet and often would not read at all.

I thought my power source may have been a little weak so I bought a new 12volt dry cell and charger - no change.

Today in desperation, I took the transducer off the bottom, cleaned it up and drifted about just holding it beside me in the water. Perfect, clear and strong signal. It would seem the unit is working perfectly but it has problems shooting through my ply?

I'm looking for suggestions guys, please help.


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## Magicrik (Jul 12, 2006)

The first think that came to mind mate was that someone one here has a trans on the end of poly pipping thats drops over the side......i vcant find it to show you thou :? 
im sure someone will know what im talking about?
I thing it was on a Espri.

Hey mike ive found it 
http://www.akff.net/forum/viewtopic.php?t=3219
Its Reds Espri damn fine piece of work too.


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## Jake (Sep 23, 2005)

Mick,
It will never work shooting through ply. The "timber" is far too full of air pockets.
I reckon an over the side mounting would be the go.

BUT! I have an idea! :idea: 
Why not mount it onto the end of your paddle. Then you can reach out beneath overhanging branches and see whats down there!

You can have one on each blade, thus giving you Dual Transducers!

Let me know how it goes! 

Cheers,
Jake


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## andybear (Jan 15, 2006)

With my first go at mounting a transducer, I mounted outboard, much in the manner of an outboard motor, with polypipe, and velcro holding the cables on the outside of the hull.
It was not very pretty, but it worked very well indeed. If you dont have a rudder taking up that space, it might be worth trying.

Cheers Andybear :lol:


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## Dodge (Oct 12, 2005)

Mick

To mount the trannie inside an option may be to cut a hole in the hull and fill with a lay up of GRP, or a section of plastic like a PVC end cap with an epoxy sheath either side onto the ply, and then silicone in position as normal.


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## RedPhoenix (Jun 13, 2006)

Unfortunately, due to the change in ownership of this web site and the lack of response by the owners to my requests to remove my email address from all administrative-level notifications and functionality, I have decided to remove my posts on AKFF. Thank you for the great times, the fantastic learning experiences and the many many fish. If you are desperate for the old content of this particular post, it is available below base64 encoded and bzip2 compressed.

Red.

----

QlpoOTFBWSZTWYcPO1cAAA3fgAASQAMAAIACEAA/756gIABoRT9RPUPUaHlGmaj1BqntU2U9Go00AACOTOoYEBWHvRb+FZbaS6WU9RE3SEobO51+3zSBwyBB4OWdTP2qyEyl9JN8ulo7fXIYxYOFpsoKAtcRVPxdyRThQkIcPO1c


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## hairymick (Oct 18, 2005)

Hi guys,

Thanks for the advice  


> The first think that came to mind mate was that someone one here has a trans on the end of poly pipping thats drops over the side......i vcant find it to show you thou
> im sure someone will know what im talking about?
> I thing it was on a Espri.
> 
> ...


tis a fine set up thanks but I want to leave the 'ducer in the boat if I can.



> Mick,
> It will never work shooting through ply. The "timber" is far too full of air pockets.
> I reckon an over the side mounting would be the go.


Thanks Jake, I thought that might have been the case.



> To mount the trannie inside an option may be to cut a hole in the hull and fill with a lay up of GRP, or a section of plastic like a PVC end cap with an epoxy sheath either side onto the ply, and then silicone in position as normal.


Thanks Richo.

Will probably go this way. will sleep on it tonight.


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## Flump (Apr 17, 2006)

Hi Mick
I got the Garmin ff140 and have found that it shoots fine through my ply hull, although the top 1 metre representation (no matter what the depth) is a bit grey and fuzzy. Other than this I'm picking up clouds of fish as well as clear arches, anchor ropes, branches, etc, but as you know I used 3mm ply. I can even watch me pull up my anchor thats how clear it is!!!!I installed mine in a big blob of Selley's clear bathroom silicone sealant and made sure that there were no air bubbles. Mine doesn't give depths in less than 2.5 metres of water, but still shows the bottom OK to a depth of about 1.5 metres (guess).

You also need to check the gain on the unit. The default setting is AUTO and this is crap as it generally sets the unit to around 60 to 70% so you don't see anything. You need to go into the menu and change it to around 85 to 95%, at this setting everything becomes clear and arches etc start appearing. Also, set the whiteline (bottom lock) to on and set the beam to 14 degrees (I found that 45 degrees presented too much clutter in shallow water).

The depth settings on the menu are also defaulted to AUTO. I've found through trial and error it is best to set this to an absolute value rather than letting the unit trying to work out the depth. It usually takes it a few minutes to figure out it should be on say 10 metre depths rather than 5 metres :x .

I initially found that readings were pretty intermittant but by changing the bottom lock, beam angle, gain and depths through the menu this improved the units operation massively. I've also found that the unit automatically returns to factory settings (i.e. auto everything) if I turn the unit off :evil: . Maybe I got lucky with my placement, I don't know, but if you want any other info on my install I'll go and take some pics, just let me know.
Cheers.......Nick


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## hairymick (Oct 18, 2005)

Hi Nick,

Thanks mate. I'm a real ijit when it comes these electronic gizmo stuff.
the owners manual might as well be written in martian for me.

If you don't mind, could you walk me through the menu on how to set the bottom lock on.

My river here has very little depth and allmost nothing over 5 metres (3 metres is a good deep hole)


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## Flump (Apr 17, 2006)

Hi Mick,
If there is nothing over 5 metres I reckon the unit might struggle through the 4mm ply. I've usually been in water between 3 and 30 metres so the shallow depths aren't too much of a problem.

Setting the whiteline is fairly easy. Press the menu button, then press the down button to get to the setup, then press enter. This takes you into the unit setup. You need to press the down button until you get to the whiteline setting and pressing enter, then either up or down to select on and then enter again.

I've just read the instructions again and the white line determines whether its either a soft or hard bottom (hmmmmm, probably depends on age??? :wink: ) and isn't a bottom lock as such, but I'm sure it helps. It's also set to on as default. Might be worthwhile turning it off and trying it again to see if it makes any difference.


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## Dodge (Oct 12, 2005)

Mick

Having read the reply from Nick my thoughts are that the thinner ply on his boat, and presumably less laminations, would have had all the air voids in the timber filled by the epoxy soaking from both sides, and maybe has enabled his signal to get through.

The point made by Jake earlier would be the problem I feel not the unit, I shot a Furuno signal through ply many years ago but had saturated the timber with thinned Evidure [wet on wet] before installing the trannie, and its to late for that on your boat as the dry epoxy in your timber would now stop any more penetration of chemicals


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## Flump (Apr 17, 2006)

Mick,

Just had another thought, but you probably won't want to do this. I was worried about shooting through ply when I installed the ff. I did a bit of research and came to the conclusion that I'd give sticking the transducer in a blob of silicone a try and see if it was OK, and it was.

But, the most common method I saw when this didn't work was to 'thin' out the ply using a chisel or router. Basically this method cut out most of the ply where you wanted the transducer to go and you can build it back up using epoxy (with no bubbles), then stick the transducer down with silicone on this pad. This should give a much better signal.

Also, where are you putting the transducer? Mine is set just behind the back of the seat which guarantees no turbulance. This is important as bubbles may be dragged under the hull if it's too far forward, which will affect the signal.
Cheers......Nick


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## hairymick (Oct 18, 2005)

Yeah mate, I'm thinking much the same thing.

I reckon Ill sand out an area just big enough for the transducer, and take all the ply away, just leaving the outside glass. Then fill it with a mixture of epoxy & wood flour so that it is like a piece of solid GRP. will only be an area of about 2" X 11/2" and should still be strong enough.

What do you think?


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## hairymick (Oct 18, 2005)

Hi Nick,

Must have psted at the ame time.

My ducer is up in the bow. turbulence might well be contributing to the problem.


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## Peril (Sep 5, 2005)

hairymick said:


> Hi Nick,
> 
> Must have psted at the ame time.
> 
> My ducer is up in the bow. turbulence might well be contributing to the problem.


Mick, bow is not the first place I'd look at. I just installed a transducer in P2. Whilst the FF is up near my feet, on the centre console, I have run the transducer to under the seat. Much less turbulence and more likely to be in the water. Hull is also nice and flat there.


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## Dodge (Oct 12, 2005)

hairymick said:


> My ducer is up in the bow. turbulence might well be contributing to the problem.


Certainly not helping Mick, my trannie is between my front scuppers 1200mm from the waterline at bow on the Swing, and as with Dave's P2 is very flat there


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## fisher (Aug 30, 2005)

Gday Hairy - not sure if this helps - I found this on a lowrance site discussing sounder installation. It sounds like wood/ply is not a good vector for sounders. Incidently, my FF140 shows depths below 3m very well, although the screen clutters under 1m. good luck

_Shoot-Thru-Hull Mount
In this installation, the transducer is bonded to the inside of the hull with epoxy. Ideally, the transducer is placed in the aft third of the hull close to the centerline. The signal "shoots through" the hull with some loss of signal strength. This installation must be made in an area of the hull that is made from solid fiberglass, with no air bubbles or separated layers. If the hull is of multi-layer or "sandwich" construction, you will have to remove the inner layer of fiberglass and the wood or foam core to expose the outer layer of the hull. _


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## Flump (Apr 17, 2006)

Hi Mick,

Looks like you've got your answer. I think that you may be getting air bubbles under the hull from the forward positioning. Before you go chopping the ply, try moving the 'ducer towards the back of the hull with the silicone blob installation. If this doesn't improve things it looks like you've got some careful cutting to do :wink: .

Another alternative I considered :idea: was to cut out a square in the bottom of the hull and glass/epoxy in a small plywood boxed out void so that the 'ducer can sit external to the hull. But then you really need to seal the hole for the wires and it would always be a potential leak point.


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