Installing a transducer in an aluminum boat

[waterinthefuel]

I haven't been on here in ages. We acquired an old Rhyan Craft aluminum boat. My father wants to install a new depth finder, but with the transducer shooting through the aluminum floor. It is a single floor boat, but I've only installed them shooting through fiberglass boat hulls. The instruction manual says nothing about installing them in an aluminum boat.

Any suggestions about if this can be done, and if so, the best way to go about it? I would assume if it is doable just epoxy it to the bottom of the boat like I did with fiberglass installations.

Any ideas would be helpful.

 

[dingbat]

I haven't been on here in ages. We acquired an old Rhyan Craft aluminum boat. My father wants to install a new depth finder, but with the transducer shooting through the aluminum floor. It is a single floor boat, but I've only installed them shooting through fiberglass boat hulls. The instruction manual says nothing about installing them in an aluminum boat.

Any suggestions about if this can be done, and if so, the best way to go about it? I would assume if it is doable just epoxy it to the bottom of the boat like I did with fiberglass installations.

Any ideas would be helpful.

The issue you run into is that the aluminum "rings" and distorts the frequency of the sonar returns. If it's an actual CHIRP or a side viewing unit, forget it.

Vexilar markets a shoot thru for aluminum boats. I have no personal experience but not heard much good about them from a performance stand point.

A trolling motor mount transducer on a transducer pole would be a better alternative

 

[cyclops222]

Clean a flat 9" area that is close to the keel. Use anything to remove oil, grease, slime. Clean bottom of transducer. On transducer bottom. Place a 2" wide by 1" high blob of Silicone Sealant. PRESS it straight down to the hull skin. press STRAIGHT DOWN ONLY !! Do not wiggle or lift it up. Put 2 pieces of cheap tape from the transducer sides to the clean hull bottom. IT will prevent a slow tipping over of the ducer for 2 days. Aluminum boats CAN BE fast and create lots of air bubbles to create messy or erratic readings.

 

[rolmops]

I have installed several airmar transducers right through the hull of Starcraft Islanders . All you really have to do is drill a hole the size of the transducer and install it.
Now because it is aluminum and because you don't want corrosion you will have to get a transducer with a plastic body. Not bronze or stainless. You also have to measure the deadrise angle of the bottom of the boat. that is because there are transducers that are built for flat bottoms , for 10 degree deadrise and also 20 degree deadrise. Drilling a hole with a diameter of 1 inch or more is a tricky thing. so make sure that you know what you are doing. When you pick a spot to put the transducer, make sure that it is not in a place where it may collide with the bunks or rollers, because the transducer will stick out about a quarter of an inch.
Airmar makes transducers with the proper wiring connection for just about any brand.
So do your homework before you buy and good luck

 

[rolmops]

The issue you run into is that the aluminum "rings" and distorts the frequency of the sonar returns. If it's an actual CHIRP or a side viewing unit, forget it.

Vexilar markets a shoot thru for aluminum boats. I have no personal experience but not heard much good about them from a performance stand point.

A trolling motor mount transducer on a transducer pole would be a better alternative

The ringing would only be an issue if you glue the transducer down onto the aluminum. the way to go is to drill a hole through the aluminum and install the transducer that way. Airmar sells them with this installation in mind.
( I wrote it this way because I always get mixed up between "through hull installation" and "through the hull installation"

 

[airshot]

I would attach to the transom and be done. Far more accurate than shooting thru a metal hull and much easier to install.

 

[rolmops]

I would attach to the transom and be done. Far more accurate than shooting thru a metal hull and much easier to install.

It certainly is the easiest way to go and while trolling it works great. But when scouting for fish at higher speeds (say 10 mph) it becomes much less so because of turbulence. Shooting through a metal hull is a no no . It does not work. The only way to go through the hull is by making a hole in the hull. and install the transducer that way. If you don't scout very much and just turn on the fishfinder and go fishing, then by all means, stick it on the transom.

 

[dingbat]

The ringing would only be an issue if you glue the transducer down onto the aluminum. the way to go is to drill a hole through the aluminum and install the transducer that way. Airmar sells them with this installation in mind.
( I wrote it this way because I always get mixed up between "through hull installation" and "through the hull installation"

Thru hull is the only way to go from a performance perspective.

I’m running a B75M as primary. Holds much better at speed than the GT 51 side scan transducer on the transom.

Problem is, most take issue with drilling a 3-4” diameter hole in the bottom of their boat

Running

 

[airshot]

Should not be an issue at speed with a transom mount transducer. I have owned many over the years, including my current Sylvan aluminum hull that is riveted. Reads very well at 30 mph, as did my 22' Star craft Islnder. If it doesn't read at speed, you have it mounted incorrectly. Numerous articles and videos on getting your transducer to read correctly with a transom mount..

 

[cyclops222]

I have done both ways. I use low cost basic fish finders Humming Birds and Garmin 150 side by side in Aluminum Lowes hull. No problems with both on at same time. Siliconed inside hull. You can mount a transducer in a glass bottom.
IF IF there is no double glass bottom with foam between the 2 bottom skins. The air bubbles in the foam MAY cause problems.

 

[FLATHEAD]

Should not be an issue at speed with a transom mount transducer. I have owned many over the years, including my current Sylvan aluminum hull that is riveted. Reads very well at 30 mph, as did my 22' Star craft Islnder. If it doesn't read at speed, you have it mounted incorrectly. Numerous articles and videos on getting your transducer to read correctly with a transom mount..

I agree with this. I’m running a Garmin transom mount GT 56 transducer and get crystal clear accurate readings at 10 MPH up to 25 MPH

 

[cyclops222]

A funny about transom transducers set below the bubbly water under the boat hull at speed.
Set the ducer to 2 inches below the hull at the dock. Go out and do 30 mph? great sonar picture. And a 6 FOOT HIGH rooster tail.
Life is Good

 

[airshot]

A funny about transom transducers set below the bubbly water under the boat hull at speed.
Set the ducer to 2 inches below the hull at the dock. Go out and do 30 mph? great sonar picture. And a 6 FOOT HIGH rooster tail.
Life is Good

Only needs to be about a 1/2 mabey 3/4" below, sometimes less. Never mount in line with rivets....angle the rear slightly lower than the front. Worse case scenerio.....smooth out the transom rivets with some body putty and sand smooth to give a smooth water flow over the transducer. My rooster tail us only about 6-8 inches tall.

 

[04fxdwgi25]

Have mounted a chunk of Starboard to transom of older boats and then mounted the xducer to the plastic. Never had a problem.

 

[dingbat]

The problem with these types of discussions is that “good performance” is subjective.

Is holding bottom at speed the standard?
Is marking a walnut at 60’ the standard?
Is marking a fish in the water column at 35 mph the standard?

The two standards I use…..

Can I mark individual fish at my cruise speed of 27 kts (31 mph)

Can I mark the water movement generated by a school of minnows (faint blue haze) on the bottom in 25-30’ of water

 

[cyclops222]

My fish finders aremost important when I go very shallow to go into flooded ponds. I get the fish by trolling and casting.
I like using my experiences on where they should be. I use sonar when I need fish for a senior meal.