Another Transducer install problem/question

[dzeppos]

Need some advice:
I attempted to install an Axiom 7 with Fishfinder/transducer. The install of the chartplotter was perfect and looks great on the dash.

However, the installation of the transducer and its location location has been problematic.
I used a stern-saver on my 2016 242 to install the transducer (t avoid drilling into the hull below the water line) and it (the stern saver) popped off the first 5 minutes in the water! that ended the day boating and had to duck tape the transducer to the hull so I could trailer it home.

Very disappointed (I left the stern saver glue dry for 10 days). My electronics/boat installer is pretty good, and I'm meeting with him later this week to determine what to do next (not sure if he is at fault or the stern saver sucks) as the transducer is now hanging by the wire off the transom. I don't feel comfortable drilling into the hull below the water line to directly mount the transducer, although it seems that its not uncommon from other boat owners on this forum.

I'm thinking of cutting the wire to the transducer for now so I can use the boat and not having the transducer dragging in the water, and after boating season, revisit how to re-install the transducer fishfinder securely, and without drilling below the water line. Any thoughts are greatly appreciated.
Thanks in advance for any advice.
Demo

 

[HangOutdoors]

Not sure what the apprehension is for drilling below the water line? Most do that mounting transducers. Not just on our boats but on all different types of boats. That is why they have sealants for that use case. 4200 or 5200. If you are worried about leaks, that would not be an issue with the sealant.

Not a fan of the stern saver. Some like using them and others don't do so well.

None the less, you can also mount it to the ride plate. Many examples on this forum on that as well.

 

[zipper]

Here is the transducer for our Raymarine Axiom 9 RV on the sailboat. It is a thru hull style. Just drill a big hole and a little hole in a flat part of the hull near centerline and seal it up.



This hole is from removing the old paddlewheel speed transducer no longer needed with gps. We had to fill/fair that all out with epoxy resin and microballoons and drill a bigger hole for the RV-200 transducer.



Plugging the old hole with microballons from the inside.



It works really well installed forward on the boat. I know the Yamaha is a different animal.

 

[zipper]

Do not cut the wire unless you are really good at solder splicing and heatshrinking. I did cut my wire, Actually I bought an extension cable to cut because it was a $75 part instead of an $800 part, because the plug on the end would not fit inside the 1 1/4" ss pedestal guard that mounts the NavPod holding the Axiom 9. There are 12 twisted pair with shielding that needs to be put back together. My splice is high and dry, nowhere near the waterline.





Putting it all back together.







A shot of the Axiom 9 yesterday while we were on the boat at the marina with 26kt winds gusting to 35kts. It all works.

 

[dzeppos]

Great information - thank you. Even though my boat stereo guy is good, (phonemical job with my Rockford amps and speakers and chartplotter) he doesn't have a lot of experience drilling into boats. I'm thinking just cutting the lien now now until i can get some time to have a boat dealer/mechanic do it (they are all so booked) (or anyone who has done it 100 times) - and pay the extra cost for the splice later to reattach at the end of the season.

 

[Andy NJ]

Mounted on the ride plate. 3M VHB tape to a piece of PVC and a nut and bolt for good measure.

Loses the bottom at 30mph. I'll mess with the angle of attack in the off-season.

 

[Julian]

Great information - thank you. Even though my boat stereo guy is good, (phonemical job with my Rockford amps and speakers and chartplotter) he doesn't have a lot of experience drilling into boats. I'm thinking just cutting the lien now now until i can get some time to have a boat dealer/mechanic do it (they are all so booked) (or anyone who has done it 100 times) - and pay the extra cost for the splice later to reattach at the end of the season.

I wouldn't cut it off.....just drill the small holes needed to mount it and you'll be fine.

 

[dzeppos]

Thanks Julian,
If they drill into the fiber glass to install the transducer directly to the hull, what resin or epoxy do you when drilling the holes?
You can see where they mounted the sternsaver originally (starboard side at the right edge of the picture and a few inches below the blue line)_- so does that location seem to work for the transducer. (It seemed to work for the few minutes we were in a no wake zone and 30 seconds we got onto plane before the sternsaver 'fell off' -which is still a mystery why it popped off so quickly (the glue inside was still wet even though I had fastened it 10 days ago)).

 

[HangOutdoors]

@dzeppos

Well it depends on what transducer you have and what its requirements are and what features you use or want to use, such as side scan etc. Not sure what the Axiom 7 recommends for lowest mounting degree from lowest part of the hull. Also the placement can be important if should you ever decide to add Trim Tabs to your boat since it may conflict.

Can you show a better picture straight on of the Starboard side and the stern saver?

The Marine Adhesive Sealant that I would use is 3M 4200. For through hull as well as the mounting plate on the transducer and screw holes. It is less permanent than 3M 5200 should you ever need to remove it, but is fantastic for above and below waterline adhesive sealant. You pre drill the holes for the screws and then counter sink them just a bit which prevents chipping. I use a 3/4" counter sink and just do a small bit. Put the sealant in the holes then screw down the mounting plate. It is not hard and with the sealant won't be a concern for any leaks. Let dry and off you go.

Shouldn't take more than 15 minutes to drill mount and seal it.

They do carry it both black and white. I keep a tube of each depending on where on my boat I am using it. On my blue hull I use black. On the white I use white.

Amazon.com: 3M Marine Adhesive Sealant Fast Cure 4200 (05260) – Semi-Permanent Flexible Adhesive Sealant for Boats and Marine Applications – White – 3 Ounces - 51135052600: Industrial & Scientific

 

[zipper]

X2 on 3m 4200. Can we assume the transducer is the Raymarine RV-100? I downloaded a pdf of the installation instructions. I would add to the hole dilling part by adding a chamfer/countersink to the holes to the gelcoat level to prevent cracks and allow more sealant in the hole.

 

[HangOutdoors]

Based on the above, you should be close where the Stern Saver was, I would just make sure you leave room if trim tabs are ever an option.

 

[dzeppos]

This is great - yes - RV-100 for the Axiom 7. Appreciate this. Will make my decision tomorrow
With respect to the water line - is that when on plane or not? Perhaps my placement is ok - based upon where I had mounted the stern saver.

 

[HangOutdoors]

On Plane. also don't sweat it. Just do it and enjoy your boat with ChartPlotter. If you remove it someday, just fill holes with glass and gelcoat, sand and finish at it will be like it was never there.

 

[zipper]

Here is the rest of it... Adobe Acrobat

You want to mount it so it is in the water while on plane or it will not work correctly. It does not like air.

Edit: What adhesive did you use? Did you tape off the gelcoat around the stern saver and scuff up the gelcoat under it, as well as the stern saver?

 

[dzeppos]

I don't know if they scuffed up the gelcoat. They supposedly used the adhesive that comes with the Sternsaver - i can see what they did tomorrow.
The mounting location was good - for the 20 seconds or so we were on plane - it was working really well - until the stern saver came off..
Looks like we'll just follow directions with the drilling and marine sealant if we decide to give up reapply the stern saver

 

[dzeppos]

I successfully re-installed the transducer on to the hull at the same location as before (and it appeared to work while in plane before the sterns aver failed) Thank you all for your help. Off to the lake house this next week !

 

[Gunner]

I used a small piece of cutting board as a stern saver. Attached it with one small screw in center of board with 5200. Its been three years and its not going anywhere. With 5200 its not going to leak.

 

[dzeppos]

So happy - two days of lake boating and Transducer for Axiom 7 works up to 30mph or so -so my position is excellent for what i need.
Very happy. I was a bit concerned that my wire hole for the grommet being only 2 inches above water line (but even then its sealed from both sides) - but it seems super tight with no additional water leaking in the boat.
Thanks for everyone's advice here.