Re: [Amel Yacht Owners] Bow thruster - Possible Solution to your problem

Bill & Judy Rouse <yahoogroups@...>


I believe that if you carefully go through this email, your problems will be solved.

I have several suggestions after reading all of your postings. I noted that after one of the seal changes everything worked fine for a year, that would lead me to believe that something is different. But, I also have unanswered questions. Let me ask the questions first:

  1. Where did you buy the foam seals?
  2. Where did you buy the lip seal?
  3. Did you know that the original external foam seals were neoprene and the interior seal was natural foam? Also it is very difficult to tell the difference. Neoprene will last longer in saltwater and does not transmit water like natural foam.
  4. Did you fill the inside of the lip seal with waterproof grease before installing it?
  5. Is it possible that the lip seal is upside down?

I believe your issue could be caused by in order of probability:

  1. You said by pulling back on the tube, you saw water pass. I firmly believe if this happened to you, your bow is too low in the water. The water line should be at least 5 or 6" below the opening and pulling back (deforming the lip seal) should produce zero water unless pounding in the sea. You also said that your first seal change lasted a year. Normally people have unloaded boats when they purchase them and load them up. If you get water passing by pulling back on the tube while not motoring or sailing, I am absolutely 100% positive that at the very least, your bow is too heavy based on what you said about pulling the tube.
  2. It is possible that you used non-neoprene foam seals externally? BTW, Amel now ships a set of 3 neoprene seals so that you cannot make this mistake.
  3. It is possible that you have an incorrect size for the lip seal, or that it is not installed correctly?
  4. It is possible that you are not using the locking pin, or that the cable needs adjusting, or both?

I believe with a high degree of certainty that your issue is 1 or more of the 4 above, and based on what you said, I am 100% positive that your bow is too low.

Modifications, including different materials, changed specifications, and/or devices installed to overcome any or all of the issues above are not recommended and you should systematically go through 1-4 above and rectify all problems found.

If I am correct regarding the bow being too low, I recommended that after correcting this, and at the earliest possible date, that you separate the motor from the tube and inspect that area and the bearing in the motor. It will be full of rust and corrosion. Clean it well and use a generous amount of waterproof grease when you reassemble....if not, it will become stuck, worse, the motor bearing will collapse. Also, an interval of 2 years is appropriate for bow thruster service.

Bill Rouse
BeBe Amel 53 #387
Sent from my tablet
+1832-380-4970 USA Voice Mail

On Jun 7, 2016 10:48 PM, "jvenegas@... [amelyachtowners]" <amelyachtowners@...> wrote:



I checked in my boat and as you mention, there is no draining tube out of the bow thruster compartment and that explain why we have been frustrated drying up with a sponge the water that regularly collects from the leaking bow thruster seals 

Since I bought my boat, I have serviced the bow thruster and replaced all seals in my SM278 several times (5 in 6 years) .   In all cases a leak developed around the lip seal soon after service. In fact, just after I bought the boat, the previous owner told me he had just serviced the thruster.  I was really shocked when I found the the compartment filled with water after just one overnight from Florida to Savanna.  I proceeded to replace all seals following AMEL instructions and the leak stopped for about a year.  That was the longest period without a leak and the start of my saga.

For the second to last service I spoke with AMEL in France and was reco mmended to add a third foam seal to the thruster assembly but that only eliminated the leak for a few weeks.  As I was about to cross the Atlantic, I developed a system with a clamp that I secured around the shaft and pushed down to create a good seal.  That worked well for the one year trip from Boston to Spain, Caribe, Santa Marta, Fort Lauderdale and back to Boston.  Although my solution is good and I recommend it to anybody doing long crossings,  as I returned to Boston it became a nuisance to have to clamp and unclamp the thruster every time we left the marina.  
So, taking advantage that I was  giving Ipanema a new bottom paint las week, I  serviced the bow thruster system for the last time and carefully cleaned the surfaces and changed again all the foam and lip seals and I added two extra turns to the top screw to bring the motor up as much as It was possible. 
Sadly, on my return trip from Glaucester to Boston unde r moderate waves I noted again a leak around the lip seal (brand new) in spite of the fact that I had to add manually quite a bit of extra tension to the cable in order to align the holes to pass the securing pin.  

Do you or anybody in this group have an idea of why is this leak persisting in my boat? 

I believe that the bottom two foam seals should be enough to completely seal the system and the lip seal should only work during the short period of time deploying or retracting the bow thruster.  So if they are not preventing a leak, it must be that in my boat poor alignment between the sealing surfaces may have developed or becomes important when tension is added to the cable to increase the sealing force.

Any suggestion about how to fix this problem.  It must not be very common as few people complain about it in this forum, but it may have been enough of a nuisance for Amel to add the tu bbing/valve to isolate and send the leaking water  to the main bilge. 

Has any one retrofitted such a tubbing/valve in SM2K earlier than the redlined version? 

Jose Venegas
Ipanema SM2K 278 
Constitution Marina, Boston MA

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