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Bow thruster tube anomaly


Davi Rozgonyi
 

Hey all... So I've had a terrible time trying to remove my bow thruster foot for service (super maramu #56 1991). I inadvertently damaged the fiberglass tube, which is another question : how do I repair it? Is it a glass job?

But it is still stuck. Tried the usual things (penetrant over weeks, chain wrench, amel tool, tapping, banging, etc). There are these little screws I've never seen before on anyone's bt or in photos. Could they somehow be holding it on? The foot was removed and greased 3.5 years ago with no problem, and barely used, so rust alone seems like a stretch...there is some but doesn't look drastic. I'm afraid to remove all of these screws because of something messes up, I'll have a hard time taking her out to a yard with no bowthruster.

Anyone know what these screws do? Any ideas on how to repair a gouge in the tube?

Thanks, y'all 


Pietro Zaccari
 

Davi, 
the small screws are to keep in place an internal metal ring that is where the 4 allen screws are screwed. Did you remove all 4 alle , some year ago I forgot one and I try to pull hard with no results, of course. 
I rem6in a previous post that someone build a tool to extract the bowthruster leg from the motor 
Good luck

Pietro 
SM 364 Bolero 
.



Inviato dal mio Galaxy


-------- Messaggio originale --------
Da: Davi Rozgonyi <davi.rozgonyi@...>
Data: 06/02/21 18:04 (GMT+01:00)
A: main@AmelYachtOwners.groups.io
Oggetto: [AmelYachtOwners] Bow thruster tube anomaly

Hey all... So I've had a terrible time trying to remove my bow thruster foot for service (super maramu #56 1991). I inadvertently damaged the fiberglass tube, which is another question : how do I repair it? Is it a glass job?

But it is still stuck. Tried the usual things (penetrant over weeks, chain wrench, amel tool, tapping, banging, etc). There are these little screws I've never seen before on anyone's bt or in photos. Could they somehow be holding it on? The foot was removed and greased 3.5 years ago with no problem, and barely used, so rust alone seems like a stretch...there is some but doesn't look drastic. I'm afraid to remove all of these screws because of something messes up, I'll have a hard time taking her out to a yard with no bowthruster.

Anyone know what these screws do? Any ideas on how to repair a gouge in the tube?

Thanks, y'all 


 

Sometimes, I forget to start with a simple solution. 

How many Allen bolts did you remove from the base of the motor? It should have been 4.

Bill
CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar


On Sat, Feb 6, 2021 at 11:04 AM Davi Rozgonyi <davi.rozgonyi@...> wrote:
Hey all... So I've had a terrible time trying to remove my bow thruster foot for service (super maramu #56 1991). I inadvertently damaged the fiberglass tube, which is another question : how do I repair it? Is it a glass job?

But it is still stuck. Tried the usual things (penetrant over weeks, chain wrench, amel tool, tapping, banging, etc). There are these little screws I've never seen before on anyone's bt or in photos. Could they somehow be holding it on? The foot was removed and greased 3.5 years ago with no problem, and barely used, so rust alone seems like a stretch...there is some but doesn't look drastic. I'm afraid to remove all of these screws because of something messes up, I'll have a hard time taking her out to a yard with no bowthruster.

Anyone know what these screws do? Any ideas on how to repair a gouge in the tube?

Thanks, y'all 


Davi Rozgonyi
 

Yup, removed 4 bolts. I checked about six times over the past week to make sure there wasn't a 5th... 


 

Davi,

I know that this is hard to believe, but I can remember at least 6 owners who experienced the same thing. I told them the most important thing you can do is be patient. In all of those cases, with all of the things you are doing, they were eventually successful without damaging the bow thruster. In my opinion, this will never happen if the bow thruster is serviced every 2 years and the bow thruster is not in use, it is locked up with the locking pin inserted. 

Were you able to apply a little twisting motion? In the hardest case, it was a very slight twisting motion (back and forth) and some vibration added to the cast iron base of the motor.

The reason the tube is stuck is saltwater entered the joint between the motor base and the tube. Rust on the cast iron base was the result of the saltwater and the rust filled the close fit between the tube and the cast iron motor base causing a very tight fit. The tube and the motor base are not rusted together because the tube is not metal. I understand that the tube is now very tight in the motor base.

Your bow thruster may be irreplaceable. I am not sure, but if not, one day soon that will be the case. It is important to take care of it like everything else I know that you do on your Amel.

I suggest that you walk away from this for a day or two.

Best,

Bill


CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar


On Sat, Feb 6, 2021 at 12:53 PM Davi Rozgonyi <davi.rozgonyi@...> wrote:
Yup, removed 4 bolts. I checked about six times over the past week to make sure there wasn't a 5th... 


Davi Rozgonyi
 

Believe it or not, I have been tapping, oiling, twisting this thing for several weeks... I am definitely sleeping on it. Do you think trying to do the Amel suggested lift and drop on the hard is a good next step? I have a scheduled lift in a few weeks but was hoping to have this done by then.

What is the tube composition? How would you repair gouges in it?

So those 8 screws do nothing to hold the thruster shaft in place? 


Juan de Zulueta
 

Hi All,
I had similar problem. Rust over the motor is creating that problem.
There is a special extractor tool sold by amel which is holding gently on the tube and extracting by moving screws pushing on the motor.
I am removing the tube every year and put a fair amount of grease on the motor connection to the tube.


Juan de Zulueta
+33680895892
sent from my Ipad.

Le 6 févr. 2021 à 13:06, Davi Rozgonyi <davi.rozgonyi@...> a écrit :

Hey all... So I've had a terrible time trying to remove my bow thruster foot for service (super maramu #56 1991). I inadvertently damaged the fiberglass tube, which is another question : how do I repair it? Is it a glass job?

But it is still stuck. Tried the usual things (penetrant over weeks, chain wrench, amel tool, tapping, banging, etc). There are these little screws I've never seen before on anyone's bt or in photos. Could they somehow be holding it on? The foot was removed and greased 3.5 years ago with no problem, and barely used, so rust alone seems like a stretch...there is some but doesn't look drastic. I'm afraid to remove all of these screws because of something messes up, I'll have a hard time taking her out to a yard with no bowthruster.

Anyone know what these screws do? Any ideas on how to repair a gouge in the tube?

Thanks, y'all 
<IMG_20210206_175033-01.jpeg>
<IMG_20210206_184809-01.jpeg>
<IMG_20210206_185334-01.jpeg>


Juan de Zulueta
 

Davi,

Don t do the lift and drop, I did it some years ago and damaged the polyester cage.
Use the amel tool or similar to extract it.

Juan de Zulueta
+33680895892
sent from my Ipad.

Le 6 févr. 2021 à 15:40, Davi Rozgonyi <davi.rozgonyi@...> a écrit :

Believe it or not, I have been tapping, oiling, twisting this thing for several weeks... I am definitely sleeping on it. Do you think trying to do the Amel suggested lift and drop on the hard is a good next step? I have a scheduled lift in a few weeks but was hoping to have this done by then.

What is the tube composition? How would you repair gouges in it?

So those 8 screws do nothing to hold the thruster shaft in place? 


Davi Rozgonyi
 

Hey all, I did buy the tool. It didn't work, kept sliding incrementally down the tube no matter how tight I tightened it... Can I put something under the metal to improve the grip?? 


 

Even though it was Amel about 12 years ago that told me about the "drop method," I do not recommend it, and, in fairness, it was before they developed the tool. 

Maybe you can fold 200 grit wet/dry sandpaper several times where the grit is outside on both sides and insert it around the tube, increasing the friction between the tool and the tube.

Bill
CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar


On Sat, Feb 6, 2021 at 1:40 PM Davi Rozgonyi <davi.rozgonyi@...> wrote:
Believe it or not, I have been tapping, oiling, twisting this thing for several weeks... I am definitely sleeping on it. Do you think trying to do the Amel suggested lift and drop on the hard is a good next step? I have a scheduled lift in a few weeks but was hoping to have this done by then.

What is the tube composition? How would you repair gouges in it?

So those 8 screws do nothing to hold the thruster shaft in place? 


Dave Ritten
 

I have had a problem removing a pinch bolt on a motorcycle and was worried that the head of the bolt was getting rounded. One of the suggestions was to put coarse grinding paste on a hex point socket to increase the coefficient of friction. Apparently this works well in cases where a tool is slipping. Maybe worth a try?
--
Dave Ritten
Auckland
Prospective SM Owner


Juan de Zulueta
 

Amel provided me a piece of hard sand paper to avoid the tool to slide on the tube as you can see on the picture I sent before



Juan de Zulueta
+33680895892
sent from my Ipad.

Le 6 févr. 2021 à 17:08, Dave Ritten <daveritten@...> a écrit :

I have had a problem removing a pinch bolt on a motorcycle and was worried that the head of the bolt was getting rounded. One of the suggestions was to put coarse grinding paste on a hex point socket to increase the coefficient of friction. Apparently this works well in cases where a tool is slipping. Maybe worth a try?
--
Dave Ritten
Auckland
Prospective SM Owner


Germain Jean-Pierre
 

Hi Guys,

I have the oldest SM. HULL 007!

I had lots of difficulty removing the foot in 2015. I used lots of WD40 and repeated use of a heat gun. It came loose eventually and is now a cinch to detach as I coat the shaft with high temp silicone grease upon reassembly.  

PATIENCE, LOADS OF WD40 AND HEAT. 

Good luck

Jean-Pierre Germain, Eleuthera, SM007
Opua, NZ



On 7/02/2021, at 10:27 AM, Juan de Zulueta <jdezulue@...> wrote:

Amel provided me a piece of hard sand paper to avoid the tool to slide on the tube as you can see on the picture I sent before



Juan de Zulueta
+33680895892
sent from my Ipad.

Le 6 févr. 2021 à 17:08, Dave Ritten <daveritten@...> a écrit :

I have had a problem removing a pinch bolt on a motorcycle and was worried that the head of the bolt was getting rounded. One of the suggestions was to put coarse grinding paste on a hex point socket to increase the coefficient of friction. Apparently this works well in cases where a tool is slipping. Maybe worth a try?
--
Dave Ritten
Auckland
Prospective SM Owner


eric freedman
 

If it is available to you a product called PB Blaster I believe is the strongest product to remove rusted assemblies.

I always drop the bow thruster a few inches every season and coat the motor spline, the bearing at the top of the spline and then use my pinky and then a q tip to fill the bow thruster receptacle. I use marine trailer wheel bearing grease for this.

 

I am not on Kimberlite today , however I was wondering if it is possible to use the long nozzle on the PB blaster can and enter the motor through the cooling slots in the side. Then pointing the nozzle as far down as possible load up the bottom of the motor with a bunch of PB Blaster. Hopefully it will go through the lower bearing and enter into the motor spline.

 

On another important subject.

Just as another preventative measure I remove the pin from the main outhaul twice annually and coat it with Never Seize. It comes out easily every time. It is not a bad idea to also remove a few thousands of an inch from the key on the outhaul shaft.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

From: main@AmelYachtOwners.groups.io [mailto:main@AmelYachtOwners.groups.io] On Behalf Of Germain Jean-Pierre
Sent: Saturday, February 06, 2021 7:32 PM
To: main@amelyachtowners.groups.io
Subject: Re: [AmelYachtOwners] Bow thruster tube anomaly

 

Hi Guys,

 

I have the oldest SM. HULL 007!

 

I had lots of difficulty removing the foot in 2015. I used lots of WD40 and repeated use of a heat gun. It came loose eventually and is now a cinch to detach as I coat the shaft with high temp silicone grease upon reassembly.  

 

PATIENCE, LOADS OF WD40 AND HEAT. 

 

Good luck

 

Jean-Pierre Germain, Eleuthera, SM007

Opua, NZ

 



On 7/02/2021, at 10:27 AM, Juan de Zulueta <jdezulue@...> wrote:

Amel provided me a piece of hard sand paper to avoid the tool to slide on the tube as you can see on the picture I sent before

 

 

Juan de Zulueta

+33680895892

sent from my Ipad.



Le 6 févr. 2021 à 17:08, Dave Ritten <daveritten@...> a écrit :

I have had a problem removing a pinch bolt on a motorcycle and was worried that the head of the bolt was getting rounded. One of the suggestions was to put coarse grinding paste on a hex point socket to increase the coefficient of friction. Apparently this works well in cases where a tool is slipping. Maybe worth a try?
--
Dave Ritten
Auckland
Prospective SM Owner


Matti Lohikoski
 

Hi Davi, in some similar land problems duct tape helps the grip. Putting tension on the parts and e.g. drill hammer (no drill but say 13mm peace of rod) you can "drill" the steel part and make it vibrate. Has been helping in some stuck parts you cannot really heat.

Matti Lohikoski SM#398



Trevor Lusty
 

Davi,
       Two hammers of equal weight tapped simultaneously on either side of a seized shaft will often free it. The problem here is the space is so restricted it is almost impossible to get any leverage or heat where you need it.
If you keep lifting and dropping it you will wind up damaging the hull.
The Amel splitter has to be your next best option with as much PB Blaster, diesel and paraffin, white vinegar and anything thing else you can think of poured on to it.
If that doesn't work, you can remove the entire assembly from inside the boat when you are hauled out. Trust me, that is definitely your final option.
I have seen one of those shafts heated to white hot  on a bench and it still wouldn't come apart.
Sometimes there is an extra grub screw (i.e. five instead of four) glassed into the bearing housing on the foot of the shaft, this is not relevant to your current problem, but might come into play later on when you get that far.
Good luck.
Trevor Lusty
Ireland


Craig Briggs
 

Davi,
You say the chain wrench is not working. If that means you have pulled on it as hard as you can and it doesn't budge the motor, you may want to try using an "old man" - a long pipe over the chain wrench handle to increase your leverage. About a meter long is good. Work it back and forth (clockwise and counterclockwise) applying increasing force each cycle (it may seem you'll break something, but likely not). After a few cycles you'll get just a fraction of movement - back off and go the other way - repeat until loose.
Good luck with it.
Craig - SN68 Sangaris, Tropic Isle Harbor, FL


Davi Rozgonyi
 

Hey there, if the shaft was heated that much and didn't separate, what was the solution?

I'm back to using the Amel tool for now. The sandpaper ring does not prevent it from slipping down despite cleaning of the shaft and tool. Other problem is any penetrant I squirt in drips straight out onto the tool. How much torque can I apply to the tool/tube? After damaging it I am leery of putting a pipe on the socket, but I have the tool as tight on as a typical Spanner can torque, held by a 180 lb person in anger.

Any thoughts on this: I have a hydraulic bottle jack. If I put some wood on the floor of the bowthruster locker (on top of the glass cofferdam box in which the foot retracts) and Jack gently up straight on the iron ring on the motor, I won't be touching the fibre shaft at all. Surely this could bust it loose more gently than banging the motor up and down, no? Or use this method to apply a bit more force than the slipping tool and then tap tap tap on the collar or shaft? 


Trevor Lusty
 

The answer was even more heat and hammering, it wasn't pretty.  The only good thing that comes out of this is, you will never let it happen again! Your jack idea I think, is going to put massive loading on the polyester which it was never designed for and I am guessing that you won't get an even pressure around the ring which may push the entire assembly out of column.  So has it the potential to do more harm than good?  Is there any way to develop Craig's idea, because I seem to remember from before, this has been solved by getting some lateral pressure onto the shaft . Unfortunately the tube is a rea PIA right now and stops you getting at the splines on the shaft.
T


 

Davi,

I know you probably know this, but a few owners applied force using the tool, and 3 days later the tube broke free. 
Tool Method (I recommend):
• Purchase the tool from Amel.
• Remove 4 Allen Head bolts spray penetrating fluid inside holes and the joint. Let it sit 24 hours.
• Clamp the TOOL near the motor base with the 4 bolts facing downward around the tube, using some medium sandpaper between the too and the tube, increasing friction between the tool and tube.
Tighten each bolt ½ turn against the motor base (if this tightening is not done evenly, you will jam the tube into the motor base)
• Repeat above until it breaks free. It may take 2-3 days with constant pressure with the tightened 4 blots for it to break free

It sounds as though the lubricant you used at the joint has lubricated the shaft and tool. Try to use something to remove the lubricant from the shaft and tool, apply force using the tool, and vibration periodically using a drill-hammer (with a piece of steel rod rather than a drill bit) and checking for tightness of the tool. Assuming days to separation.

Patience.

A hammer drill, also known as a percussion drill or impact drill, is a power tool used chiefly for drilling in hard materials. ... The percussive mechanism provides a rapid succession of short hammer thrusts.
image.png

Bill
CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar


On Sun, Feb 7, 2021 at 8:01 AM Davi Rozgonyi <davi.rozgonyi@...> wrote:
Hey there, if the shaft was heated that much and didn't separate, what was the solution?

I'm back to using the Amel tool for now. The sandpaper ring does not prevent it from slipping down despite cleaning of the shaft and tool. Other problem is any penetrant I squirt in drips straight out onto the tool. How much torque can I apply to the tool/tube? After damaging it I am leery of putting a pipe on the socket, but I have the tool as tight on as a typical Spanner can torque, held by a 180 lb person in anger.

Any thoughts on this: I have a hydraulic bottle jack. If I put some wood on the floor of the bowthruster locker (on top of the glass cofferdam box in which the foot retracts) and Jack gently up straight on the iron ring on the motor, I won't be touching the fibre shaft at all. Surely this could bust it loose more gently than banging the motor up and down, no? Or use this method to apply a bit more force than the slipping tool and then tap tap tap on the collar or shaft?