Transducer Install query

[isljam]

Hey folks.

I am doing my first transducer install on my 4.5m Aluminium Brooker runabout and need a little advice please.

I’m aware I need to choose a flat, unobstructed point on the transom to mount. Avoiding chines, welds and hardware etc, to ensure unobstructed water across the transducer.

The concern is that the weld along the bottom of the transom creates a small ridge. So, running along the hull it is smooth until it meets the transom. There, the water would have to travel over the small ridge created by the weld. The manual for the unit recommends mounting 10mm below bottom of hull.

Is this going to create a disturbance in the operation or the transducer. Of course, there is no way to avoid it as the weld runs the entire length along the base of the transom.

Should I attempt to file / sand this weld line flat or could this jeopardize the integrity of the weld?

Thanks

[Corry]

Have you got a transducer mounting plate welded to the back of the transom? If not, I would suggest to go see an alloy welder and have a plate welded on, that way you can bolt the transducer to the plate without having to drill holes in the transom. At least then if you upgrade or change it later, your not left with holes below the water line. Be careful drilling the holes in the mounting plate that you don't drill through the transom, slide a piece of steel in between to help. 

As for mounting, don't worry about the transom weld, most boats have it, definitely don't go filing or grinding it away. As far as height to mount it, there is plenty of info out there in the google world, but majority of the mounting brackets allow vertical movement, I've found that I've needed to mount it lower than 'recommended' to keep good picture at higher speed, you might have to 'play' with it over time to see what works. They say centre of transducer should be level with bottom of hull, and mounted between any rakes or chines, half way between outboard and side of boat. 

Hope this helps somewhat.

Cheers, Corry

[Hweebe]

Do not file / grind the weld unless you want to cause future problems.

As @Corry mentioned a Transducer mount plate is definitely preferred as not doubt you will need to play around with or adjust the height of the transducer via trial and error.

Install it and see how it's reading at low / high speed. If you then find issues with the transducer reading make small adjustments. (Plenty of info on the internet)

The tip is is you value high speed reading then the angle of the transducer is more forward facing. Slow speed then stick to the install recommendation.

Consider one of these to help with adjustment (if you don't get a plate welded on)

https://www.whitworths.com.au/aluminium-flat-adj-centered-transducer-bracket

 

[isljam]

Great info. Thanks guys.