Winterize stabilizers?

The learning curve continues.

OUR Defever 44 has Naiad stabilizers (model 173). I'm about 750 miles from the owners manual and see nothing on the Naiad site or elsewhere online addressing winterizing these. There is a raw water line running from the starboard engine to the main stabilizer unit housing and a discharge line from the unit overboard. Thought I could blow it out, but there's total resistance on the feed line and I don't see an obvious drain fitting. Cold weather approacheth and I'd sleep better if know this unit won't freeze up.

Why not pull the hoses and drain it that way? That's what we did on my 252 system when doing some work on it.

You can call Naiad, they are usually very helpful. 203.929.6355

Each vessel is specific since hose routes vary dependent upon cooler and engine configuration. Is the boat on the hard or in water? ER heat on?

Most stabilizer coolers have zinc ports which can be opened up. My hoses do not drain overboard but are part of the exhaust elbow loop. How is your cooler fed - separate pump from RW?

As Caltexflanc says, pull off the hoses. Also drain the water lift muffler. Generally a flush with AF is done before cold weather arrives, that is what I've done in the past when on the hard in the NE or in the water on the Mississippi.

What has been done to winterize the vessel so far, winter temps have already arrived in some places. Good luck and stay warm.

Thanks, guys. The rest of the boat is already winterized.

The water supply line runs from just downstream of the raw water pump to the stabilizer housing. No dedicated pump. I removed this line and blew on it and it feels blocked. No gurgling or bubbles in the unit and no air flow whatsoever. (There is a gate valve in this line that I plan to remove to see if that's the problem. It drains overboard.

I talked to the guy at Naiad who did not have a lot of specific advice about winterizing. He said to put some air pressure on the supply line to blow the water out. I'll look for zincs but the Naiad guy said the unit cannot be drained except by air pressure.

After getting some guidance from two Naiad techs, I hooked up the air compressor to the supply line and blew some antifreeze through it at about 35 psi. Worked like a charm.

Thanks for the ideas.

Did you run pink through the engine's raw water system as part of winterizing? I would think that would flow through the stabilizer cooler too. Was the stuff you blew out pink?

twistedtree said:

Did you run pink through the engine's raw water system as part of winterizing? I would think that would flow through the stabilizer cooler too. Was the stuff you blew out pink?

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I did and it was. I just didn't notice the water lines to the stabilizers when I was doing the engines. Tonight, I watched it discharge pink into the sea chest. Craig, at Stabilized Marine (who could not have been more helpful) told me the only time he sees damaged heat exchangers in these units us when they freeze. I'll sleep better tonight knowing it's protected.

Craig is awesome and has a great memory, his wife Tammy keeps a great log on each boat that has Naiads added or serviced by them. He installed our Naiads for a previous owner and I was very happy with his work and recommend him to anyone needing work.

I plan on installing Wesmar fin stabilizers on my 50' Chris Craft.
Few questions to the guys having Naiads:
- If you looked at Wesmar, what made you choice Naiads?
- Are you satisfy with the result? (in 3 to 4' foot sea? and in stormy sea?)
- Did you notice significant speed decrease? and how is the handling?
- Do these accumulate a lot barnacles or sea weeds? (do they need to be cleaned when diving?)

Thanks

Francois said:

I plan on installing Wesmar fin stabilizers on my 50' Chris Craft.
Few questions to the guys having Naiads:
- If you looked at Wesmar, what made you choice Naiads?
- Are you satisfy with the result? (in 3 to 4' foot sea? and in stormy sea?)
- Did you notice significant speed decrease? and how is the handling?
- Do these accumulate a lot barnacles or sea weeds? (do they need to be cleaned when diving?)

Thanks

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Have you also looked at ABT-Trac?

I looked briefly at Wesmar when I added stabilizers to my 47' Grand Banks, but went with ABT because of their uniformly stellar customer reviews, and because they struck me as the most over-engineered of the batch.

The GB is a planing boat that will do 22kts or so, and I noticed no difference in top speed. Zip, nada, zero. Performance is outstanding. I don't know anybody with stabilizers who would ever consider another boat without them. Come on over and become part of the converted crowd . On my Nordhavn we ran a bunch of tests during commissioning with and without the stabilizers on. That boat is displacement speed only, but we saw either improved speed, or the same speed with the stabilizers on. Never was it slower. Basically the boat moves move gracefully through the water and as a result doesn't lose speed, and actually gains speed in some cases.

As for cleaning, the fins are just like any other part of you below-water hull. They are painted with anti fouling, and would be cleaned just the same as other parts of your bottom. No special treatment or consideration required.

Good luck with the project. If you want to see the gruesome details of an installation, check this out Adventures of Tanglewood: Installing Stabilzers on a 47' Grand Banks

Here are some pics of ours.

Note the kelp cutter located just in front of the fin.

Thanks for the information and pictures. I'll look at the other brand and base on your input and other comments, my wife should enjoy these stabilizers (and as a result, we should do more boating !!!)


I like the idea of the kelp cutter...


We plan to start the project in mid January here in Corpus Christi Texas and I'll post pictures as they perform the work (re-gelcoat all, stabilizers, shaft work, extra fuel tanks, and swim platform extension to 5')

Just curious, bit what is the purpose of a cooling line on the Naiads? I have ABTs and don't have that, nor can I imagine the need .

I'd be surprised if your ABTs don't have some form of hydraulic cooling. If you just have stabilizers, it's probably via a heat exchanger with raw water from the main engine if it's raw water cooled, or a dedicated sea water pump if you have dry stack. Where the water comes from is very boat-specific, but it's probably in there somewhere.

Delfin said:

Just curious, bit what is the purpose of a cooling line on the Naiads? I have ABTs and don't have that, nor can I imagine the need .

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I don't have the manuals with me, but the Naiad techs told me the hydraulic reservoir has a copper cooling coil inside. (Also a thermometer on the tank). The supply line T's off of the engine raw water line just downstream of the pump. The discharge goes to the sea chest. They are the red hoses in the photo. When I expressed concern about copper mixing with sea water the techs told me they'd never seen one fail.

twistedtree said:

I'd be surprised if your ABTs don't have some form of hydraulic cooling. If you just have stabilizers, it's probably via a heat exchanger with raw water from the main engine if it's raw water cooled, or a dedicated sea water pump if you have dry stack. Where the water comes from is very boat-specific, but it's probably in there somewhere.

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We're all hydraulic, and the oil is cooled, in our case via keel cooler. I guess the answer is that absent a system like that, Naiad provides for local cooling of the oil at the stabilizer?

Delfin said:

We're all hydraulic, and the oil is cooled, in our case via keel cooler. I guess the answer is that absent a system like that, Naiad provides for local cooling of the oil at the stabilizer?

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Ah, I get it. When you say "all hydraulic", do you mean hydraulic thrusters as well? On my boat, it's equipped with a keel cooler for the hydraulics, but if you also have thrusters ABT specs an additional heat exchanger and raw water cooling loop+pump. But they are also very conservative when it comes to engineering, so it may be overkill.

By the way, your boat has a twin in Gloucester. I love 'em.

twistedtree said:

Ah, I get it. When you say "all hydraulic", do you mean hydraulic thrusters as well? On my boat, it's equipped with a keel cooler for the hydraulics, but if you also have thrusters ABT specs an additional heat exchanger and raw water cooling loop+pump. But they are also very conservative when it comes to engineering, so it may be overkill.

By the way, your boat has a twin in Gloucester. I love 'em.

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Thrusters, fore and aft, fore and aft windlasses, Pacer pump, hi pressure wash down and boom controls for tender launcher. So we have a 15 gallon or so tank with an exchanger and keel cooler. I guess I didn't realize you would need cooling if all you had was stabilizers, but I suppose over time they would still generate enough heat to require cooling.

There were just three of these Romsdals built, Ulysses, Delfin and the now named Torsk. Is it Ulysses near by? I think Torsk is in the Adriatic.

Well, I might be all wrong on the boat, but let me dig up a picture. It was called tanjin or something like that.

Delfin said:

I guess the answer is that absent a system like that, Naiad provides for local cooling of the oil at the stabilizer?

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Apparently they do both . . . either a line off the raw water system to the oil reservoir or, in the larger Naiads, a dedicated pump. Any of the systems can be adapted to "external" coolers. As for the need for cooling, my manual says that for every 18 degrees F above 120, the oil life is shortened by half.

angus99 said:

Apparently they do both . . . either a line off the raw water system to the oil reservoir or, in the larger Naiads, a dedicated pump. Any of the systems can be adapted to "external" coolers. As for the need for cooling, my manual says that for every 18 degrees F above 120, the oil life is shortened by half.

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That's a good formula to know. Thx.