FISHFINDERS

[DSPCHAMY]

You can do an epoxy in the bilge area as long as you have a 20 or 60 degree transducer. If you go any wider than that you will have a lot of trouble with feedback or you just will not get a reading on the screen. You will just be bouncing sound waves of the inside of your bilge.

Thru hull is actually a diffrent type of transducer where you drill a big hole through the bottom of your boat and the transducer rests on the pad of your boat. Never been a big fan of putting that size hole in my boat, but they say its much more accurate.

[Moose1am]

I think that most of the other replies have covered almost everything.

A few things I will add. You can put a old toilet plunger on the floor of your boat and temporarily glue it in place. Fill this plunger up with water and then stick the transducer down inside to that the bottom face of the transducer is covered with water. Make sure that the transducer is cleaned with soap and water to remove all oils from it's surfaces before you install it and to maintain it after it's installed. This setup is a temporary setup to locate a good position in your boat. You want to put the transducer in a location that is free of electrical interference and air bubbles that can form while the boat is underway. Carefully look at the boat's back end while the boat is running. You may need to have someone else drive the boat while you lay down on the back deck and look at the back of the boat. Look for an area that has LAMINAR Flow and no bubbles. This is the area of the boat where you want to install the transducer. If you see areas that appear to have lots of turbulence or air bubbles then you don't want to put the transducer in that kind of area. Air bubbles between the bottom on the boat and the lake bottom will interfere with the sound waves so they must be avoided at all cost. Also you won't want to put the transducer too close to the engine if you mount it on the outside of the transom of a boat. But you are looking to mount it on the inside of your boat.

The plunger glues to the floor and filled with water will let you test various area of your boats floor for a good spot. Test it well and make sure that the spot you choose will work under all conditions. Especially while you are using the electric trolling motor and at Full speed. It should work well under both conditions. You won't have to deal with air bubbles at trolling motor speed under 2 mph but at high speed you can loose the sound signal returns if you have bubbles under the boat.

Once you find a good spot you can remove the temporary mount and clean the area thoroughly of any oils and grease or other contaminates. You will want a smooth surface to epoxy glue the transducer to the boat's floor. You must not have any air between the transducer and the lake bottom. The transducer must only contact the glue and the fiberglass floor of your boat and the epoxy glue shall not have any air bubbles in it when it sets. You can press down on the transducer and squeeze out the air bubbles in the epoxy glue and then put weights on top the transducer until the epoxy cures. You must not have a two layer floor with any spaces under the transducer. This is imperative that you follow this as any spaces in the floor will stop the sound waves from traveling though the bottom of the boat and then prevent sound waves that bounce off the bottom from reaching the transducer. Also think of the area you want to mount the transducer and imagine the angle that part of the boat makes with the water's surface as you are going different speeds. It should be able to shoot sound waves straight down below the boat as you are going fast and on plane. If the bow of the boat is up then the transducer may shoot the sound waves out forward more than straight down which is not a bad thing at slow speed of 10 mph or so. That may allow you to see ahead of the boat a ways.

Thru the hull transducers are those that are actually put though a hole in the boat's bottom. These are made out of heavy brass with the transducer attached to the brass. They fit through a hole drilled in the bottom of the boat and will actually stick below the bottom of the boat. I have never seen anyone use these in freshwater lakes. These may be more for the ocean fishing boats that never venture in to shallow water. These units must be sealed in place to prevent them from leaking water into the boat. I for one am not keen on drilling a 2" hole in my boat but then again I use an Aluminum boat.

I tried to mount a transducer in the bottom of my aluminum boat but the way the floor is make in the john boats it was not working very well. The rivets on the bottom of the boat make a lot of air bubbles when I an going over 15mph. So I ended up mounting my transducer on the outside of my boat back on the transom. It sticks down into the water about 1/2" deeper than the bottom of my boat but it has a kick up feature in case it hits something.

You can drill and put a piece of thick 1/4" Hard White Plastic sheet on the back of your boat's transom. That way you only have to have two bolts though the transom to hold the sheet of thick plastic onto the transom. Then you can mount the transducer to the plastic. Depending on the mounting hardware you may need a thicker plastic sheet of 1/2" thickness. I have seen these plastic mounting plates on sale in the BASS PRO SHOP Catalog. This way you can mount the transducer onto various spots of the plastic and not have to drill new holes in the boat's transom. You just drill new holes in the plastic sheet instead. Once you find a good position that has good water flow without air bubbles you are good to go.


Regards,

Moose1am

[smalleychaser]

Thanks for all the great information.
This really helps.
TCB