Re: Bow Thruster Service
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Bill is right about being careful in heating grp. Grp can delaminate/crack and thereby destroying the strength of the material if too much heat is applied. I used to build GRP stack sampling equipment that could barely handle 350F..not much.
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-------- Original message --------
From: CW Bill Rouse <brouse@...>
Date: 8/28/19 7:21 PM (GMT+01:00)
Subject: Re: [AmelYachtOwners] Bow Thruster Service
You should be very, very careful with heat because the Bow Thruster Tube and case is made of GRP, not metal.
The contact point is Cast Iron to the GRP tube. The problem is a result of NOT replacing the lip-seal and foam donuts, and possibly leaving the bow thruster down while sailing or motoring. Saltwater has passed through the seals and has caused corrosion on the electric motor base which is made of Cast Iron. This corrosion (Iron Oxidation) has reduced the size of the opening for the tube at the base of the motor. Your photos show that this has been more than a little saltwater over a long time, possibly months/years. It is going to be very difficult to separate the tube from the motor base. You will need the tool designed by Amel, plenty of penetrating fluid and 3-4 days of constant pressure to cause separation. You can use some light tapping or vibration on the cast iron motor base intermittently while constant pressure is applied with the special tool. But take care not to strile the base too hard because it is made of cast iron.
I recommend that you closely check the lower bearing on the electric motor because I suspect it is also damaged.
In the future, replace the seals every 2 years...also replace the 0.3 liters of 80/90 Gear Oil when you replace the seals. Always use plenty of waterproof grease at the contact points of the tube and motor base.
This is the normal materials needed for service every 2 years (contact SAV"at"Amel.fr):
You will certainly get other advice, but I firmly believe that you will not get better advice.
On Wed, Aug 28, 2019 at 12:03 PM Matt Salatino via Groups.Io <firstname.lastname@example.org> wrote: