Transducer Install

YYZRC

I want to install an active imaging transducer on the trim tab. I know this isn’t recommended but I don’t want to drill the transom and I’m wondering if anyone has done this? I realize it won’t work on plane but I don’t need it then anyway. 

The style of transducer seems ideal for flush mounting on the tab. 

Aqua_Aura

Use a transom saver to install it. Basically a piece of starboard glued to the transom then you screw into that. I have heard good things but haven't installed mine yet. If you are worried the flu won't stick you could put one screw in the middle of the starboard and use sealant around it. 

This is what I bought

https://www.amazon.com/dp/B079DWDDWC/ref=cm_sw_r_cp_apa_glt_fabc_SDTP7JQ9DDWAF3645VAQ?_encoding=UTF8&psc=1

I do plan to put one screw in the middle and I will put some sealant on the backside of the starboard where the screw pokes thru them stick it to the transom and screw it on. 

YYZRC

I saw those but starboard can’t be glued so I assume it’s pvc or some other plastic. 

Maybe I will try the transducer and see what happens. Worst case I have a few holes in my tab. 

Aqua_Aura

Just make sure you can attach it so it's parallel to the water. Seems like trim tabs are angled outward. 

LaRea

Why are you worried about drilling the transom?  It's two small, short screws.  Pre-drill, dab with sealant, install.  Easy and safe.

Willhound

Agree @LaRea . The hull at the bottom of the transom is about 1 3/4" thick if not more. Couple of short screws and sealant. That other thing, I'd worry about it impeding on the proper operation of the trim tab and the wire on it being constantly flexed up and down.

LaRea

Yeah, I think mounting it to the trim tab is not a great idea. 

The transducer has a hinge that flips up to save the transducer if you hit something.  When you lower the trim tab at cruise speed, you'll have water hitting the transducer at an angle.  The force will probably flip the hinge, and then you'll have to swim to reset it. 

As @Aqua_Aura said, the trim tab is angled with the hull's deadrise, so your transducer won't be pointed down unless you install a wedge to level it.  

Also, the transducer might overheat if it's out of the water when the trim tab is up.  

YYZRC

Thanks gents. I know it is not the optimal or recommended approach. Just curious if anyone had done something like this. I’m not a hard-core fisherperson or a diver searching for structures to explore, so I don’t need optimal performance. Really just depth and water temp.

I will ponder it over the winter. Too late in the season to fuss with now!

davidbrooks

I think you are going to find out this is a bad idea. An interesting one though.  I have that transponder.  So you do have to drill through the transom whether you like it or not to run the wire up to the MFD.  That hole gets filled with 5200. The wire will need a couple of small wire clamps screwed into the transom to keep it in place so there are a few small drill holes there.  However as mentioned by others.  you aren't going all the way through.  The other thing is that it is pretty sensitive to want to at just the right point on the water line.  Too high and you get too much turbulance and it messes with the signal, too low and the same thing.  Mine will continue to send in a good reading up to about 20-22 mph.  Oh one more thing.  That picture is messed up.  The end with the wire is up against transom on the hinged plate.

YYZRC

Thank you @davidbrooks ! Any pics of your install?

LaRea

However you mount it, the transducer has to be level or it won't be able to measure depth.  The sonar beam has to travel down to the seabed, and reflect back up to the transducer.  

skennelly

What I did was glue with 5200 a piece of PVC board from the hardware store.  That Aztec stuff.  Then screwed the transducer to that.  Been 6 years and it's not going anywhere.

davidbrooks

No recent pics.  It is in between the engines about a foot or so above the keel on the starboard side.  I then ran the wire up another 12-18in and drilled through the transome so i would be above the water line and away from important stuff in the engine compartment.

Liberty44140

You will want depth on plane. When you enter a new harbor, or get away from the channel, you want to know what the depth is and if it is getting shallow too fast. On plane is when you really don't want to hit anything.

To drill in to the transom just make sure to over drill the hole and epoxy the hole. Then come back and do as stated above in using a good sealant, I use 4200 and not 5200. The epoxy "washer" is key to ensuring that your transom stays solid as you will be screwing in to epoxy, not wood. I used West System Six10 to re do my tabs and underwater lights last spring and it was awesome! 

PickleRick

When mounting to my hull below water line I make my initial pilot holes.

I  drill those holes out to about 3/8 and slightly deeper than my mounting screw.

I clean the hole out with acetone and q tip.

I mix up some epoxy resin, dab a little with the q tip to wet the core and fiberglass. 

I  add thickener to the resin until its about like toothpaste. 

I then take a syringe about the size of what you'd use to season a turkey and push the resin in the hull until full.   I then wipe the surface of the hull flat with a putty knife.  

I clean any excess resin up with acetone and clean rag  

I put some painters tape over the holes to dry for 24 to 48hrs depending on temps.

I redrill my pilot holes, carefully thay i don't go past my epoxy insert.

Finally  install your transducer with 4200 (you know you're going to upgrade later )

If the 4200 ever fails you won't get any water in your core as epoxy resin absorbs less moisture than your vineylester gel coat.

Any time I've cut open a transom the water has come from trim tabs or transducers or anything  going thru the hull below the water line. 


I also like the starboard mount but if you use a screw to hold it while the glue sits id use the same method. 

LaRea

@PickleRick that's a good process for large fasteners in a cored transom plate.  A transducer mount has small screws going into solid glass down at the bottom edge.  

PickleRick

I don't know about your hull but on my Bayliner and on my 235 fv the outer hull shell is only about 3/8 to 7/16 thick.  Then a 1.5 inch or so wood core and then the 1/4 inch inner skin.  

The transducers I've purchased usually come with screws around  @3/4 inch, they go in well past the fiberglass hull and into the wood core.  

My bottom hull wasn't thick enough at the bottom to fit all the transducer mounts into the bottom solid fiberglass. 

Liberty44140

LaRea said:

@PickleRick that's a good process for large fasteners in a cored transom plate.  A transducer mount has small screws going into solid glass down at the bottom edge.  

I didnt think about how low this will be mounted. Yea if it really is going in to solid glass where the transom meets the hull it would make sense to not need any additional epoxy. I think I'd drill it out and if you see any wood.... then you know you need epoxy. If not, good to go...

PickleRick

Your pilot holes will certainly spit out wood if you hit it.  I try to use electrical tape to mark my drill bit for how deep I want it to go. 

J3ff

Aqua_Aura said:

Use a transom saver to install it. Basically a piece of starboard glued to the transom then you screw into that. I have heard good things but haven't installed mine yet. If you are worried the flu won't stick you could put one screw in the middle of the starboard and use sealant around it. 

This is what I bought

https://www.amazon.com/dp/B079DWDDWC/ref=cm_sw_r_cp_apa_glt_fabc_SDTP7JQ9DDWAF3645VAQ?_encoding=UTF8&psc=1

I do plan to put one screw in the middle and I will put some sealant on the backside of the starboard where the screw pokes thru them stick it to the transom and screw it on. 

Mine has been on for the entire time I've owned the boat.. think it's stuck there for good (I'm sure when I go there in three hours it'll have fallen off now)

MarkB

So, when you change the trim tab angle, it's going to point the transducer on an angle too, and then??  You aren't going to get an accurate reading of the bottom.

J3ff

I think it would not be good with all the pressure.... 

SimcoeRinker400

I installed my transducer off the back couple holes but sealed them with 5500 and shared the underwater light hole for both transducer and light.  The transducer seems to work great at all speeds.  Did the same install on my old 342 and it worked great also.  Remember, I had to reseal my trim tab screws back in June as the Portside was leaking into the boat I used 5500 to redo them and everything has been dry ever since.  I would not be worried about drilling holes as long as you seal them well.  Picture from the spring after installing new light and probe.  First test of probe second picture. 

YYZRC

@SimcoeRinker400 did you cut and splice your transducer cable or did you punch a 3/4”’ hole? I’m leaning toward cut and splice. A 1/4” hole seems more reasonable?

Aqua_Aura

Use one of these. 

https://www.bluesea.com/products/category/23/Cable_Clams

Are you sure it's 3/4" you need to drill, seems excessive. I think mine is less than a 1/2" 

YYZRC

It’s probably 1/2. I was being dramatic

skennelly

There are transducer cable junction boxes on the market with weather tight seals and terminal strips for the wires.

SimcoeRinker400

I drilled the hole then epoxyed the wood core to make sure if some water gets through the 5500 3M sealant which is highly unlikely. Plus it is above the waterline so no biggy

davidbrooks

I don't think I would recommend cutting off the end just to have a smaller hole. The internal wires are small and you would likely mess with the signal from the transducer. 

skennelly

@davidbrooks - That's what I've read as well, but airmar sells the splice jbox and wire bar so I guess it's possible to do it.  I'd be skeptical about just soldering things together.  If at all possible don't cut it would be the answer

Willhound

Don't cut. Tiny, tiny strands of wire and transducers can be finicky if a splice causes any extra impedance in the wire. Use the clam shell if the hole bothers you.