Thru Hull Transducer installed

Vince_nj1

Vince_nj1

Active Member
TECHNICAL Contributor
Aug 25, 2008
1,819
North Barnegat Bay
Boat Info
2006 320 V-Drives 6.2s, Bow Thruster, Generator, Raymarine C80, Radar, Fish Finder
Engines
6.2 Horizons 320HP
My big winter project was to add fish finding/sonar to my Raymarine C80 over the winter. I was able to get a great price on the transducer and DSM 30 at the NY boat show.

I installed the thru-hull transducer over the Christmas break. Technically the installation was pretty easy: Drill a hole using the correct size hole saw, sand and clean both the inside and outside of the hole, apply liberal amounts of 5200, install the transducer and gasket and tighten the nut. This is a picuture from the inside before the 5200, gasket and nut were installed.
P1020965.jpg



The actual installation however was pretty difficult. It was a real bitch trying to tighten the nut while doing a head stand in the bilge. I was able to thread and tighten the nut by hand, but I had a had a very difficult time trying to get a channel lock on the nut to torque it down. Fortunately my friend with long arms was helping me and was able to reach the nut and tighten it for me. Everything looks good, but I cant call it a success until the boat goes back in the water and I confirm that there are no leaks and the unit is working.


I took a few pictures of the hole that I drilled and the core of fiberglass that I removed. I was a little surprised how thin the fiberglass was. Take a look:

P1020971.jpg
 
Is there a fairing on the outside, or is that an angled transducer?

When I added a new thru-hull, my hull was cored, not solid like yours. So I drilled the outer section at the desired diameter and the inner two sections at a greater diameter.

The cores were scouped away. The whole thing was filled in w/ epoxy resin w/ filler.

It was then drilled out again.

Lots of work...
 
The unit is a flush mounted "tilted elemenant" transducer, no faring required.


tilt.jpg
 
Nice Job!
I did the same thing on my 310DA.
It is scary drilling a 2 3/8" hole for the first time isn't it?????

Lee
 
I definetly was a little nervous about drilling the hole, but my friend assured me that it wouldn't be a problem. He said he drilled several holes in his boat and never had an issue. We will see when it goes back in the water on April 1st.

Having all of the fiberglass dust fall on my face while I was lying on the ground drilling the hole was a real treat. :smt119 I just kept my eyes closed and kept blowing the dust away with my mouth. (Standard OSHA procedure :thumbsup:) When I was done, I felt like I washed my face and dried it off with a piece of insulation. :smt009
 
As an FYI, I posted this some time ago:

http://clubsearay.com/forum/showpost.php?p=143179&postcount=31

There is some thought now about not leaving 5200 as the only barrier between an unfinished fiberglass edge from a hole being cut and the water... if the 5200 has any leak for whatever reason, it can wick up the fiberglass (core or no core)...

Just an FYI.
 
To tighten the nut for the 'ducer consider a Crow's foot wrench for a 1/2" drive rachet and an 18" extension.
SNX97741.jpg

I'm not sure of the dimension of the nut, but the large one's can be rented and may be able to save you from the Bilge Yoga circus act with Channel locks.

I've used these on safes when I've worked on them and it sure saves strain and awkward positions.
 
Vince_nj1 said:
.......... lying on the ground drilling the hole was a real treat. :smt119 I just kept my eyes closed and kept blowing the dust away with my mouth. (Standard OSHA procedure :thumbsup:) When I was done, I felt like I washed my face and dried it off with a piece of insulation. :smt009
Click to expand...

Know what ya mean.
Smells good too!!
LMAO......
 
Four Suns said:
As an FYI, I posted this some time ago:

http://clubsearay.com/forum/showpost.php?p=143179&postcount=31

There is some thought now about not leaving 5200 as the only barrier between an unfinished fiberglass edge from a hole being cut and the water... if the 5200 has any leak for whatever reason, it can wick up the fiberglass (core or no core)...

Just an FYI.
Click to expand...

Thanks for the heads up. I guess its a little late for me now. I did some research before attempting this and found that the general consesus was that drilling a larger hole and filling with epoxy was only necessary only if the hull was cored.

At this point, I will keep my fingers crossed that the 5200 will do its job. If I had easier access to work, I might have gone the extra mile, but since space was so tight, I was happy just to get the nut tight..

Does anyone know how Searay does it at the factory? Do they drill larger holes and then back fill with epoxy?
 
I definitely agree with Gary and would have used epoxy on the inside of that hole. I don't care what people say, but I do not have confidence like others do with 5200. To me it's just a heavy duty sealant. Over time, all sealants tend to dry out/erode away and lose effectiveness.

Doug
 
Vince_nj1 said:
Does anyone know how Searay does it at the factory? Do they drill larger holes and then back fill with epoxy?
Click to expand...

I don't know about the factory, but my Sea Ray dealer did seal the edges of the hull where they cut through using epoxy when they did my transducer. They cored the hull to the diameter required, sealed the cut edge with epoxy and let it cure, and only then installed the transducer with 5200.
 
There is no doubt that there is a good way to do it, and a great way to do it. That being said, back before this forum when I was still a new cruiser owner (1997), I took a drill and some large, but standard bits and drilled a hole in the bottom of my '97 250 DA for a Bronze scoop and through hull for a live well. I gouged the area out on a mounting block in the bilge with a bit until I could fit the fitting in the hole, and then a little more.

I then used the stuff that Boater's World told me to (probably 5200, just from remembering the sticky mess...) and coated the inside of the hole, the threads on the through hull, and then added enough to fill the gaps and gush out each end when I threaded the nut. 10 years later, when I sold the boat, it still wasn't an issue.
 
Four Suns said:
As an FYI, I posted this some time ago:

http://clubsearay.com/forum/showpost.php?p=143179&postcount=31

There is some thought now about not leaving 5200 as the only barrier between an unfinished fiberglass edge from a hole being cut and the water... if the 5200 has any leak for whatever reason, it can wick up the fiberglass (core or no core)...

Just an FYI.
Click to expand...

I'm getting ready to install my transducer for similar project Vince had. I'd like to take the opportunity and learn from this thread in regards to protecting my fiberglass with epoxy. I have a question on how much and what part should I cover with epoxy, just the side walls of the whole or also edges, including going on the surface inside the boat and on the exterior? I'm just thinking that when epoxy hardens it might be not as smooth and flat as the current surface. Am I over thinking this?
 
It would just be the inside of the hole.

Technically, it's a good idea. Check the 'ducer fit, if you epoxy the inside of the hole you're going to reduce it's diameter a bit- so you might need to oversize the hole slightly.

I've never bothered with it, and never had a problem in twenty-five years. If the prep for the 5200 is done properly (bottom paint removed and fiberglass cleaned/free of contaminants) there will never be an issue.

The BIGGEST issue with thru-hull transducers is location, location, location.
On a late model boat, I'd ask SR for the preferred location for the transducer. You only get one shot at this, and if not done correctly it will not hold bottom when on plane.
 
Just had a Airmar B60-20 installed by MarineMax Clearwater. Decided to have them do the transducer since the boat was in for service and hauled out. They located the B60 next to the SeaRay depth transducer and used 4200. I asked about the 4200 and was told so that it could be removed if ever needed. Last weekend I was able to get the DSM30 installed with the SeaTalk Switch and NEMA 0183 Mux all working, even had the Autocomp 1000 heading sensor hooked up. Although I still need to select a location and route the wiring for the Autocomp 1000...any suggestions? Hope to get to the RD424HD radar install this weekend.
 
tobnpr said:
The BIGGEST issue with thru-hull transducers is location, location, location.
On a late model boat, I'd ask SR for the preferred location for the transducer. You only get one shot at this, and if not done correctly it will not hold bottom when on plane.
Click to expand...

tobnpr,

Thanks for your suggestions. I was thinking of the same location where Vince had his installed. But, I would like to double check that this is the best spot for it. Contacting SR is a good idea.

From what it looks like on the picture the transducer is right behing the transmission. I'm still trying to figure out if it's starboard or port side. If I recall it was the stbrd side. Vince can you confirm?

Edited:
I was able to find where Vince had stated that the location is "Starboard side of the boat below the transmission".

Vinces_Transducer_Installation.jpg


Edited:
I just got response from SR where all they sent me a PDF file with the following image:

B60-20_Choosing_Correct_Spot.jpg


Does it look like it matches the spot where Vince had his transducer installed?


mawyatt said:
Just had a Airmar B60-20 installed by MarineMax Clearwater. Decided to have them do the transducer since the boat was in for service and hauled out. They located the B60 next to the SeaRay depth transducer and used 4200. I asked about the 4200 and was told so that it could be removed if ever needed.
Click to expand...

mawyatt,

Thanks for the post. This is a bit puzzling, wouldn't two transducers interfere with each other? Also, the use of 4200 seams interesting approach. I would imagine that these ducers don't last for ever, so chances are it might have to come out. You got me scratching my head now with which one to go 4200 or 5200? WM has the following overview on 4200, which looks like it quilifies for the job:

Cures fast and forms a watertight seal between joints and hardware


One-part, all-purpose sealant chemically reacts with moisture and forms flexible, watertight, weather-resistant seals on joints and hardware. Can be used above or below the waterline; approximately half the strength of 3M’s 5200, which allows for eventual dissasembly of parts. Note: Can be softened by some teak cleaners and sealers and is not recommended for sealing teak decks.
  • Formulation: One-part fast-cure polyurethane adhesive/sealant
  • Recommended Usage: Fiberglass, wood, metal, some plastics, above or below water
  • Material Incompatibilities: Acrylics ABS, Lexan
  • Cure Time: Tack free: 2 hrs; complete cure: 24 hrs
  • Cleanup: Mineral spirits or kerosene
  • Removal: Mechanical removal
  • Tensile strength: 300psi
 
Last edited:
The two transducers don't interfere with each other because they operate at different frequencies. MM located the B60 just to starboard of the depth transducer. The local Clearwater MM does lots of work, and many big boats as well (many 50~60'+ SR and Hats), so I figure they know what they are doing.
 
mawyatt said:
The two transducers don't interfere with each other because they operate at different frequencies. MM located the B60 just to starboard of the depth transducer. The local Clearwater MM does lots of work, and many big boats as well (many 50~60'+ SR and Hats), so I figure they know what they are doing.
Click to expand...

mawyatt,

Thanks for the info. I've heard/read many good things about Clearwater MM.

I'm looking at the transducer's specs and trying to figure out of the frequencies are really different.

My existing P17 shows these frequencies:

P17_Frequency.jpg

P17_Frequency_Depth_Performance.jpg


B60-20 shows these:
B60-20_Frequency.jpg


I'm not an expert but is this what they refer as to different frequenies 200kHz-A (P17) and 50/200kHz-A (B60)?
 
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