Transducer fitment advice ???

[disorderly]

I have had a problem ever since I fitted my transducer ...
Its for my Furuno sounder and I think it's an Airmar..
The transducer is square shaped with a straight wedge shaped front on it and the problem is that it does not read at speed (over 10-12 knots)and also tends to throw up a rooster tail of water behind it.
What I would like to do is to use some type of product to fill the maybe 5mm gap between the ducer and the bottom edge of the hull in the hope of eliminating these problems.

Just wondering what may be best to use ???.

Scott

[Spaniard_King]

Scott,

put a couple of pics up.. give ua a look :).. of the transducer.. not the engine;) 8-)

[disorderly]

I will have too get some better photo's tomorrow Garry....these were the only 2 that came out OK.

[Local_Guy]

looks like it's sitting way too high... you gotta lower that thing into the water... give it atleast 2cm.

my opinion.

[Pridey]

Yeah mate, get it submerged. About 20mm is good. Also angled straight. as long as its not behind an angle on the transome or a corrigation on a tinnie should be good. A lot of people have dramas with transducers at speed... but 10-12 knots isnt good.

[ANYFISH]

Gday mate
I have just read the book that came with my furuno and airmar transducer and it said to fill the gap with an epoxy. So i guess aryldite will do the trick. Just make sure it is a smoothe transition between hull and transducer so there is no turbulance. The book also said to keep the bottom faceabout 2-5degrees lower at the rear of the transducer to help with smoothe water flow.

Is tht a rib in front of the transducer in the photo?? Just check for anything that would create turbulance in front of the transducer along the hull.

Send a pm if you want more info from the book

Cheers Anyfish

[Whitto]

Mate forget about filling up gaps the transducer isn't low enough, get the top surface of the transducer at least inline with the bottom of the hull......You will definatedly see a big difference........Whitto

[finding_time]

Scott

I'm inclined to agree with the others but could you post a side on shot so i can have a look at both depth and angle!

Ian

[Pridey]

Btw, Nice outboard...

[Spaniard_King]

Yeh Scott.. the boys are onto it.. get it deeper.. but as Ian said give us a look from side on.

Y ou really cant have them too deep...they will just create a bit more spray :)

[disorderly]

Btw, Nice outboard...

She's a little beauty,that one http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/wink.gifhttp://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/smiley.gif.

Guy's, I will get a better photo this afternooon....
The front edge is mounted between 2 strakes and is flush with the bottom of the hull.
There are 2 reasons why I am not sure about lowering it further......
One is because I am wary about having it smashed by floating debris.....
The other is the shape which would catch the water and direct it upward...it's an odd transducer.
I also have a garmin transducer which is more the conventional shape, mounted at a similar height, just to the right of that furuno one and it works much better at speed .

Anyfish,is this the same transducer that you have?

Scott

[finding_time]

Scott

Here's a pic of my old ub's transducer it read perfectly all the way to 30 knots. See how the line of the hull hits about half way up the transducer and the transducer is very very slightly facing foward. It is always going to get clean water across it's face;)

Ian

[Thunderbird]

By what everyone's said Ian, your transducer is sitting to high as well. perhaps it doesn't have anything to do with the transducer or boat.. could it be all the computer interfearance from the engine management systems on those evinrudes? yeah more like it..

[FNQCairns]

yeah get it down deeper and lower it's bum somewhat, mine will only work well with twice the advised angle then you you can do away with the filler at least as a part trade.

I have the airmar and they are very hard to get working apples to apples, they need to be deep, a foot down would suit mine perfect!

I had to throw away my learned rule book and go aggressive with depth and angle, finally it now works OK not great but OK.

Blokes with deeper V, glass or plate with no or less lifting stakes than a pressed tinny get the easy airmar fitting options.

We have to dance around it a bit more.

cheers fnq

[shanza]

Hi scott

I had a similar problem when i first installed my furuno, i did everything as per manual but still had poor readings at speed. I fixed this by lowering the transducer into the water more and it now works like a dream.

Hope this helps

shanza

[disorderly]

Just took some more photo's but only one came out.My photography skills really suck.http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/sad.gif
Hopefully though it shows my dilemma.
My garmin ducer, much like the one in Ian's(finding time) photo above is fitted similarly and works fine.

However the photo below shows the flat front face of the furuno ducer and it is angled back maybe 15 degrees with the bottom jutting out the furtherest.....see what I mean,it's an odd shaped transducer??...what happens is that it catchs the water and forces it upward...sometimes up to a metre and a half or so and onto the motor as well.

Do any of you guys that have found lowering the ducer has helped, actually have this type of ducer and if so what can be done to stop the water spout happening?

Scott

[FNQCairns]

Scott that one would make a great trailer sailor transducer! They mixed up the young fella's work experience design file with the paid blokes!

What about a piece of alum sheet that mounts tothe hull under the existing SS transducer bracket using the same screw holes and bent to extend the hull until it meets the transducer proper, effectively covering that gap, it could be bent at larger than 90deg if you go lower with the transducer than now and if there is a small gap or if it may flex up with speed some marine sika to fill the mm or so gap.


cheers fnq

[nick_75au]

Hi disorderly,
To answer your first question, I think if you use sikaflex to fill the gap it may partially solve the problem, will make it a bit of a bugger to get off later;D and may not give you the result your after.
What is probably happening is either air trapped under the hull is crossing the face or the unit or air is being sucked in the gap between it and the hull. the sika will only fix it if its the second problem.

To really fix the current transducer I would make some sort of mold onto the front of the Transducer in the shape of a plum bow boat to fair the water either side of the unit and use epoxy or sika to fill the mold.
I've attached a quick drawing to describe what I mean. The transducer will need to be lowered as everyone else has mentioned and the new fairing will deflect any aerated water around rather than under the face of the transducer.
Regards
Nick

[finding_time]

Scott

Mate as fnQ and nick have stated Your going to have to modify either your transducer shape ( with something that sticks on) or modify the bottom of your hull with some sort of fairing block ( better idea i think) Because you have got to get that transducer lower. Pressed tinnies sit higher in the water than plate and glass boats and trap more air under the hull at speed this is then traveling over the face of your presently positioned transducer. get it lower!

Ian

You cant worry about stuff hitting your transducer whilist under way either if it lower chances are it wont but if it does it's really a case of sh!t happens

[marco]

if you still intend to fill the gap after lowering it , the furuno tech from the usa recommended that the gap be filled as well as setting up the transducer correctly ( as everyone has said above ) and to fill the gap with some of that expanding foam in a can stuff and to finish with a epoxy resin .

[disorderly]

Scott that one would make a great trailer sailor transducer! They mixed up the young fella's work experience design file with the paid blokes!


cheers fnq

Totally agree,Scott.
I've had this thing for a year now and I still can't figure out why it was designed as such.http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/undecided.gif

Some good idea's there fella's...I'll have a think about devising something from the idea's above them and let you know how I get on..

Yes Ian, I agree that if by lowering the transducer and it get whacked by some debris than that's just life,isn't it.......http://www.ausfish.com.au/vforum/../yabbfiles/Templates/Forum/default/smiley.gif

cheers fella's ....now I have something to work with anyway.

Scott

[hookinin]

Looks nothing like the airmar transducer i run with my furuno not saying its wrong but is it possible to get a different transducer. That one looks like it should only be on a sailing boat or displacement hull. Just another option that may be easier in the long run?.
Good luck Gaven

[Outsider1]

Here is a link to Airmar's product pages. You should be able to find your Transducer details there. Certainly sounds like it might not be the right style for a planing hull transom mount.

http://airmartechnology.com/airmar2005/ex20/RMProducts/OpenData.asp

Cheers

Dave

[Outsider1]

Here is a link to Airmar's product pages. You should be able to find your Transducer details there. Certainly sounds like it might not be the right style for a planing hull transom mount.

http://airmartechnology.com/airmar2005/ex20/RMProducts/OpenData.asp

Cheers

Dave

I can't find an Airmar Transducer that look even remotely like the picture you put up Scott.??

Dave