Re: Bow thruster seals

 

Danny,

I believe that yours is adjusted and operated perfectly.

Best,

Bill Rouse
720 Winnie St.
Galveston, Texas 77550
832-380-4970



On Mon, Jun 10, 2019 at 2:54 PM Danny and Yvonne SIMMS <simms@...> wrote:

Hi all,

I find it hard to understand why vessels built the same have such different experiences. Some never leak and some cant stop leaking.

However there may be a clue from many previous posts discussing how to get the right amount of lift by the electric retraction system. This seems to show an expectation that this motor will lift the thruster to its full retracted position allowing the insertion of the retaining pin. The retaining pin has a threaded adjustment so it can be made to suit where the motor has lifted the thruster to. However, the foam seals, to work, need pressure applied beyond that which the motor can achieve. (those who try may explain the number of burnt out motors). I have mine adjusted so the motor lift stops with the seals in contact. However at this point I have a "half hole" situation for the pin. I achieve the insertion of the pin by a strong sideways pull on the lifting cable and the tapered end of the pin assists this as I push it in. This results in good pressure on those foam seals. I have at times left a marina and motored down harbour with the thruster lifted but the pin not in and had significant leaking which immediately stops when I do the final lift and insert the pin. This confirms my experience that good pressure on the foam seals is needed for them to work. The lip seal is important too but without the foam seals working properly there is a huge hydraulic water pressure upwards as the boat pounds into a seaway that overcomes the lip seal.

That's my take on this.

Regards

Danny

SM 299 Ocean Pearl

On 11 June 2019 at 03:29 Stephen Davis <flyboyscd@...> wrote:

 
Hi Jose,

I’d also be interested in some of these seals, as water intrusion in spite of good bow thruster maintenance has been an on going problem for us. On our 31 day passage from Panama to Hawaii we had fairly bad leakage, and I built a mountain of modeling clay I had on hand around the shaft to stop it. That will completely stop the inflow for about 10 days until the clay gets saturated, and you have to pull it off and put some more on. I’d recommend everyone keep some on board for emergency repairs on long passages, as it beats the heck out of bailing water several times a day. The best solution might be your new seals, and I’d love to give them a try. 

Regards,

Steve Davis
Aloha SM72
Ko Olina, Hawaii

On Jun 10, 2019, at 9:59 AM, CW Bill Rouse < brouse@...> wrote:

Jose,

I too am interested in the source and part number.

Best,

Bill Rouse
720 Winnie St.
Galveston, Texas 77550
832-380-4970



On Mon, Jun 10, 2019 at 9:35 AM ianjenkins1946 < ianjudyjenkins@...> < ianjudyjenkins@...> wrote:
Hi Jose,

In your original email you write of  having bought two seals and " installing them". Presumably you only installed one, replacing the 60-80-12 that Amel fitted ?

 Incidentally, to save you the  hassle of buying  a number of seals and then sending  them on, I'm happy to buy direct, in which case could you let me have the part number ?
 Equally, I'm happy to add to your own order if that helps to speed up supply.

 Thanks,

 Ian and Judy, Pen Azen, SM 302 Greece
 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> on behalf of ianjenkins1946 <ianjudyjenkins@...> <ianjudyjenkins@...>
Sent: 10 June 2019 07:46
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] Stuffing box drainage path
 
Hi Jose,

 This solution sounds really useful. We are definitely interested. Please contact me on    penazen@... so we can arrange payment and post.

 Ian and Judy, Pen Azen, SM 302, Greece
 

From: main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> on behalf of Jose Venegas via Groups.Io <josegvenegas=icloud.com@groups.io>
Sent: 10 June 2019 02:12
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] Stuffing box drainage path
 
Dear friends:

After I bought Ipanema 10  years ago we had two years of struggle trying to prevent the leak of water through the bow thruster.  About 8 years ago we had a long discussion on this forum about the bow truster seals which I had changed several times following all the recommendations given by Amel, including adding a third bottom donut seal to increase the pressure.  It was all at no avail.  So, before our transatlantic on 2012 I came up with a brute force solution adding an extra removable sealing system that was wrapped around the shaft and had to be secured after the bow thruster was fully retracted.  This worked very well during the trans Atlantic passage (not a single drop of water) and gave me the security of knowing that in addition of the sealing effect, the shaft was being held by one redundant mechanism. 
As we came back to Boston, we kept using the method but it became very inconvenient to mount and dismount the contraption every weekend when we left and came back to Constitution Marina.
My interpretation of the problem was that due to uneven wearing of the surfaces that guide the bow thruster up and down motion, it resulted in a misalignment between the shaft and the sealing surfaces.  This misalignment  caused a small deviation  of the shaft from the centerline which pushed the lip seal sideways and, because the Amel recommended seals are made of a hard material, it opened a point of water entry. 
I proceeded to test my hypothesis and ordered two special seals made of silicone from a soft seal manufacturer (SSP Inc).  It took several months to get them due to the small number of units I ordered (just 2) but, after I installed them three years ago, I had no more leaks and my bilge has been dry ever since.  The cost for the two seals was $72.50 and, more importantly I have not had to change them or the donut seals since I installed them. I have checked them and the donut seals and they are all still in good shape.

As I am preparing Ipanema for our long term cruise, I am ordering a few spares to carry with me and I will be happy to order some extra ones for any body that wants to try them.

I missed taking pix before installation but here are pictures of them installed, before and after adding the top donut.

Cheers,

Jose Gabriel Venegas
Ipanema SM2K 278
Boston

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