Advice on These Thru Hulls From Raymarine

[Madehn]

Just got my new set of i50 / i60 speed and depth instruments from RayMarine.
i was less than thrilled when i opened the boxes to find plastic thru hulls and hardware for these. i REALLY dont want to put plastic thru hulls on the boat and have reached out to see if they make bronze thru hulls for this application. i suppose i could use off the shelf thru hulls but then they dont have the neat little flapper valve that shuts off most of the water when you pull out the sensor to clean it. Am i overthinking this? Is plastic ok in this application? If they dont make a bronze set of sensors, it looks like even if i use off the shelf bronze thru hulls i will still be stuck with a plastic nut holding this whole thing together. would like others experience and thought on this before i pull boat to install. Thanks in advance. ( every other thru hull in the boat has been replaced with new with a GP03 backing plate that is epoxy to the hull then valve is screwed in and valve flange is bolted into threaded holes in the GP03 backer plate. - Was a lot of work but they look great and are sturdy as all heck.) I hate the idea of putting two plastic thru hulls into this mix.

[Knotical]

What do you have now? My 1987 boat had plastic transducers that weren’t working and I replaced it with new plastic ones, boat is still floating.

Airmar transducers are used by tens of thousands of boats, just think what would happen to the company if all those boats had sunk.

[ItDepends]

Airmar transducers are used by all of the major instrument companies, and the only difference from one to another is the plug on the end of the cable.

Gemeco Marine is the big distributer of these, and their catalog is a treasure trove of information, including the pinouts for all models.

MOST Airmar transducers are available in plastic, bronze or stainless housings.

But before you get too bent out of shape... you DO (like most of us) have a plastic boat...

[Matt Johnson]

Try busting one off before you get too worried. They are shockingly strong and a real pain to break apart - when you can't get one out otherwise.

[Madehn]

thanks all for the quick replies- yes i do have a plastic boat BUT 1 1/2 fiberglass is a little different from the cheesy sides of these thru hulls not to mention the plastic nut on top of them- -- good to hear that they have bronze housing transducers- i sassume that they make those because there is a need for something sturdier / longer lasting than the plastic ones-- or maybe there is just a market for paranoid types that worry about the plastic ones as for what i have right now, the boat's depth was from a transducer mounted on the inside that shot through the hull without a thru hull fitting- did not have any speed other than GPS. Thanks again all for your replies- am reaching out to airmar and to the vendor that i bought the units from.

[ItDepends]

Originally Posted by Madehn

thanks all for the quick replies- yes i do have a plastic boat BUT 1 1/2 fiberglass is a little different from the cheesy sides of these thru hulls not to mention the plastic nut on top of them- -- good to hear that they have bronze housing transducers- i sassume that they make those because there is a need for something sturdier / longer lasting than the plastic ones-- or maybe there is just a market for paranoid types that worry about the plastic ones as for what i have right now, the boat's depth was from a transducer mounted on the inside that shot through the hull without a thru hull fitting- did not have any speed other than GPS. Thanks again all for your replies- am reaching out to airmar and to the vendor that i bought the units from.

The NEED for metal thru-hulls comes from wooden boats. The wood swelling when wet can crush plastic fittings, but not metal ones.

If you really think your boat is 1.5 inches thick... you might be in for a surprise. It is closer to 0.5 than 1.5

But... I agree with the emotional support from a nice solid piece of bronze!!!!

[stormalong]

That cheesy nut is just to hold it in while the caulk hardens up. Besides being cheaper plastic won't be affected by galvanic corrosion from stray currents and you don't have to worry that they used the right alloy.

[Searles]

In some cases plastic through hulls are not to be used in vsls in survey , hence in wood or grp or some composites ,so bronze or ss or available ,in my experience the so called plastic ones are verry strong .⚓️⛵️��

[Madehn]

After reading some of the replies, i thought perhaps i was being a bit paranoid and did some more research-- what i found at practical sailor tells me that my instinct that these nylon thru hulls are NOT a good idea for this type of below water line sensor. I have since gone back and ordered new thru hulls (bronze) made for the RayMarine i50/i60 setup. Here is the article from practical sailor:
https://www.practical-sailor.com/sys...h-hull-warning

No disrespect for those that feel they are strong enough-- your boat your choice but i think i am going to go with practical sailors advice and my gut.

[MicHughV]

Plastic is not to be confused with Marelon.

Bronze thru-hulls have their issues too. My previous boat had bronze thru-hulls. A lot of them. On one haulout I decided to remove the tapered plug to re-hone them.
Much to my surprise, I found severe pitting on both the tapered plug and internal housing.

I rubbed grinding past on them and rotated the things till my arm fell off, but could not get rid of the pitting. Even when the valve was closed, it leaked.

'jes sayin'......

[Madehn]

i totally agree on the marelon-- but the vendor specifically said that the thru hulls supplied with the Raymarine package were nylon-- still might not have been an issue given that the location of these should be low in the hull where exposure to UV should be lower and they dont have a hose leveraging on them from inside the boat. Stull not overly happy that the sensor is held in with a nylon nut but it is what it is. The new brass thru hulls made for the sensors were an additional $400 but i will sleep better-

[noelex 77]

An even safer option to consider where possible is to assemble a coffer dam around the depth and speed transducers.

If the transducers are near the bow often the height required to reach above waterline is not excessive. Waterproofing the walls of a locker or a storage area under the bed are common solutions.

This also contains the salt water that enters when the log is cleaned.

[Madehn]

"even safer option to consider where possible is to assemble a coffer dam around the depth and speed transducers."

not a boad thought! i am thinking maybe a large diameter PVC pipe that extends up to above water level ( deep bilge ) but that i can still reach down to pull the sensor for cleaning. THANKS FOR THE IDEA

[MicHughV]

Since the advent of GPS, chartplotters, etc. the use of a speed sensor is somewhat moot.

Most hull speed sensors come with a "plug" in the even the sensor is removed.

Were it me, and this is my modi operandi....I just leave the plug in and fugetabout the speed sensor. In the past, I have tired of diving aboard to clean that little paddle wheel.

With the advent of GPS, I see little use for it.....but that's just me.

[Madehn]

I am thinking that the wind instruments use input from the paddle wheel when figuring true and apparent wind speeds. Am I mistaken in this? If not you maybe absolutely correct that the whole paddle speed sensor thing is a dinosaur.