Have you ever been in a position where you’re itching to cast a line but still don’t know how to mount a transducer on an aluminum boat when installing your fishfinder?
What should I be mounting on? Should I drill holes in the first place? These questions crossed my mind when I was mounting a transducer on my aluminum boat for the first time. Chances are, the same goes for you.
Below, I’ve shared two of the best ways to go about with transducer mounting on an aluminum boat. The first involves using a standard mountain plate, while the other involves a bit of improvisation with a PVC board but is still effective.
Table of Contents
Materials To Prepare
If you’re going for the conventional mounting plate or transducer board route, gather these tools beforehand:
- Mounting plate or transducer board
- #2 slotted cordless drill
- Marine-grade silicone
- Metal drill bit (the size depends on what the product asks for)
The alternative, no-holes method will require:
- Any PVC board that’s the appropriate size for your boat and transducer
- Marine epoxy
What do I prefer between the two? Well, I’m a little hesitant to favor one over the other. There are pros to both. The first option feels more secure to me, but the alternative means you won’t have to put holes in your boat.
I tend to lean more toward the latter because I always cringe at the thought of drilling holes in any vessel. Besides, PVC boards tend to last for years.
However, I can also make the argument that the first option doesn’t really affect the integrity of the boat. By this, I am referring to the fact that mounting plates typically only need two holes to be set in place.
How to Mount a Transducer on an Aluminum Boat
The actual mounting of any transducer board is fairly straightforward. Still, you’ll have to be aware of a few factors when you install a fishfinder on an aluminum boat, especially when deciding where to position it. Be mindful of these when deciding:
- Assuming your boat uses a high-speed skimmer, know that you’ll always need to keep its position in mind relative to the fishfinder’s. These skimmers often need to have clean water coming over their bottoms. You’ll need to mount the transducer in such a way that the fast speeds of the skimmer won’t interfere with the former’s bottom reading.
- Beware of the positioning of your rollers too. Make sure the rollers don’t end up hitting the transducer every time you have to get them out when loading or launching the boat.
- Whether you’re installing a side-imaging transducer or a high-speed one, be sure you position it in a way that it’s clear of all rivets on the bottom of the boat. These rivets tend to create air pockets that interfere with the transducer’s functionality.
- Position a side-imaging transducer slightly lower than a high-speed transducer so it won’t interfere with the latter.
- You can leave more room to adjust the position of your transducer by using a wider board. At least 7 inches should give you plenty of space.
With the above points clarified, we can now start mounting.
1. Position Your Mounting Plate then Make Drill Marks
To me, the best position is at least half an inch from the bottom of the boat. Hold the plate in that position with one hand. Then, using a cordless drill and bit, make drill marks on your boat’s transom with the plate’s mounting holes as your guide. Apply just enough force to make a mark.
Also, a note on the screws and drill bit you need to use: the drill bit should only be slightly smaller than the screws used to mount the transducer board. So, once you drill, the screws will always have a firm bite the moment you set them in place in the holes you make on the aluminum.
2. Apply a Gob of Marine-Grade Silicone Next to the Holes then Drive the Screws in Place
Place marine-grade silicone around the holes you drilled. You can also draw a silicone line between the two holes to strengthen the adhesion. I don’t pull punches when securing the transducer board, so any way you can up the security of the board is more than welcome.
Now, you can start setting the mounting board in place. Simply set the screws in the hole, insert them, and drive the screws in. Don’t go overboard with it. Once the screws are snug, you can stop.
3. Mount the Transducer of Your Choice
The instructions for this should be provided by the product you bought. It shouldn’t be too complicated, since you can always adjust its position. If you use a wider board, you will get more leeway when making your final decision. For more tips about this step, I highly recommend you watch this video:
Mounting Using A PVC Board
The positioning guidelines I mentioned above still apply to this alternate option. Another great thing about this is that it’s a lot cheaper, but just as durable. Anyway, here’s how you can go about it.
Head to a lumber yard and look for a sturdy piece of PVC board. Even better if you already have one on hand. You can adjust its size according to how much allowance you want for your transducers.
Once you get it to the right size, just glue it in place! You’ll be using marine epoxy to secure it, so don’t skimp on the adhesive. If I’m going to recommend two, I’ll go for Star Brite and Marine-Tex epoxies.
Did you like my methods on how to mount a transducer on an aluminum boat? I’ve been relying on either one when mounting transducers on multiple vessels for years. The main reason is that they haven’t given me any issues at all. Plus, I get the opportunity to fine tune my transducer effortlessly. If you have further questions or feedback, don’t hesitate to comment below!
“I am James Harvey – founder of Boating Basics Online. It is established with the drive to help out first-time boaters, which are those desiring to explore their way through the water. So if you are new to boating, start from here with me. “