Bowthruster - damaged hex-nut [count on drilling out that bolt and re-tapping the hole + TORX]


David Vogel
 

Thanks Chris,

 

All good info.  And, having spent already 2 days on this problem with no meaningful progress, it looks like this issue is not going to be solved in the day of so of slack I have in the schedule for this haul-out.

 

And with more to add to the mix, from other interested and assisting parties, is a suggestion to replace the HEX bolts with TORX, as these are less prone to slippage and damage.

 

https://www.mcmaster.com/torx-bolts/drive-style~torx/

 

 

 

From: <main@AmelYachtOwners.groups.io> on behalf of Chris Doucette <amaroksailing@...>

Reply-To: <main@AmelYachtOwners.groups.io>

Date: Wednesday, 8 December 2021 at 8:46 am

To: "main@AmelYachtOwners.groups.io Group Moderators" <main@amelyachtowners.groups.io>

Subject: Re: [AmelYachtOwners] Bowthruster - hex-nut securing he motor to down-tube is stripped out

 

Hi David,

 

I have done a lot of work on the bow thruster these last few months..  In Fact I have rebuilt the entire thing inclusive of the motor bearings.  Basically, count on drilling out that bolt and re- tapping the hole..  It really does not matter if it ends up 9mm vs the original 8mm. But first- get it drilled out. You might have to find a short 8mm drill bit with a right angle drill adapter. Those steel screws go into a brass fitting inside the bow thruster shaft.  It  is what you will tap eventually. Replace the bolts with quality 316 SS bolts, with copious anti-seize. 

 

Once you get it all out- be sure that the bearing in the base of the motor is going to be shot! I took everything appart in the motor also to change the bearings and snap washers, cleaned, brushed off rust, chemically treated the rust, and sealed that large steel base with epoxy and paint.  It looks like new and will not rust as it did. Re-tapped all the screw holes in the brass part. Almost all done here - bow thruster painting is underway and then assembling. 

 

Chris

 

Amarok, SM 385 

 

 

 

On Mon, Dec 6, 2021 at 8:10 PM David Vogel <david.vogel@...> wrote:

Greetings fellow Amelians,

 

Requesting help with a 'small' problem.  After an extended service interval (>3-years since last service of the Bowthuster by AMEL MQ, the unwanted delay due to cruising French Polynesia in COVID times, closed borders, and so on), we're now securely in NZ, primarily for the purposes of attending to long-overdue rounds of routine maintenance - including as a high priority the Bowthruster and C-Drive.

 

Three of the four 6mm hex-bolts that secure the bowthruster motor to the fiberglass (?) torque-tube have been removed without undue problems - desite some rust clearly evident (due I think to the aging neoprene compression seals) with just the regular tightness as expected, but overcome with normal force of a 15cm shifter (no heat or penetrating oil needed).

 

Unfortunately, the fourth bolt - the starboard-hand one oriented forward - was found to be almost completely stripped, and the limited attempt to shift it finished the job.   It now presents a round hole, which provides no ability to use an Allen key (either 6mm, or the next size up in imperial) to gain the necessary purchase.  The forward-facing location presents  challenges in terms of access needed to drill and tap in an "Easy Out".  Without drilling, the easy-out can not be inserted far enough to gain any useful purchase.  I have applied heat (MAP//Pro torch) as close as possible to the nut head.  I am also soaking the joint (and the whole motor-tube interface area) with PB Blaster (now also anticipating problems with dropping the tube away from the motor assembly).

 

Has anyone faced this problem with a rounded hex-bolt before, and found a solution?

 

Or are there any other tips and trick, hints or suggestions?

 

Thanking you in anticipation, and with kind regards,

 

David

SM#396, Perigee

On-the-hard, Riverside Drive Marina

Whangarei, New Zealand

 

 

 

 

 


Eric Freedman <kimberlite@...>
 

Twice a year I put a hose clamp on the bow thruster body and remove the 4 bolts that hold the motor to the thruster.

I drop the thruster and apply a lot wheel bearing grease to the bearing in the motor and then clean the

motor spline and bow thruster  female portion. I put WWW.NEVERSEIZEPRODUCTS.COM on both sections and clean the bolts and apply neverseeze. The bolts always come out easily and the thruster drops out rapidly.

 

 

If you are so inclined, you can also replace the lip seal and the donuts at the same time.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

 

From: main@AmelYachtOwners.groups.io On Behalf Of David Vogel
Sent: Tuesday, December 07, 2021 3:25 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] Bowthruster - damaged hex-nut [count on drilling out that bolt and re-tapping the hole + TORX]

 

Thanks Chris,

 

All good info.  And, having spent already 2 days on this problem with no meaningful progress, it looks like this issue is not going to be solved in the day of so of slack I have in the schedule for this haul-out.

 

And with more to add to the mix, from other interested and assisting parties, is a suggestion to replace the HEX bolts with TORX, as these are less prone to slippage and damage.

 

https://www.mcmaster.com/torx-bolts/drive-style~torx/

 

 

 

From: <main@AmelYachtOwners.groups.io> on behalf of Chris Doucette <amaroksailing@...>

Reply-To: <main@AmelYachtOwners.groups.io>

Date: Wednesday, 8 December 2021 at 8:46 am

To: "main@AmelYachtOwners.groups.io Group Moderators" <main@amelyachtowners.groups.io>

Subject: Re: [AmelYachtOwners] Bowthruster - hex-nut securing he motor to down-tube is stripped out

 

Hi David,

 

I have done a lot of work on the bow thruster these last few months..  In Fact I have rebuilt the entire thing inclusive of the motor bearings.  Basically, count on drilling out that bolt and re- tapping the hole..  It really does not matter if it ends up 9mm vs the original 8mm. But first- get it drilled out. You might have to find a short 8mm drill bit with a right angle drill adapter. Those steel screws go into a brass fitting inside the bow thruster shaft.  It  is what you will tap eventually. Replace the bolts with quality 316 SS bolts, with copious anti-seize. 

 

Once you get it all out- be sure that the bearing in the base of the motor is going to be shot! I took everything appart in the motor also to change the bearings and snap washers, cleaned, brushed off rust, chemically treated the rust, and sealed that large steel base with epoxy and paint.  It looks like new and will not rust as it did. Re-tapped all the screw holes in the brass part. Almost all done here - bow thruster painting is underway and then assembling. 

 

Chris

 

Amarok, SM 385 

 

 

 

On Mon, Dec 6, 2021 at 8:10 PM David Vogel <david.vogel@...> wrote:

Greetings fellow Amelians,

 

Requesting help with a 'small' problem.  After an extended service interval (>3-years since last service of the Bowthuster by AMEL MQ, the unwanted delay due to cruising French Polynesia in COVID times, closed borders, and so on), we're now securely in NZ, primarily for the purposes of attending to long-overdue rounds of routine maintenance - including as a high priority the Bowthruster and C-Drive.

 

Three of the four 6mm hex-bolts that secure the bowthruster motor to the fiberglass (?) torque-tube have been removed without undue problems - desite some rust clearly evident (due I think to the aging neoprene compression seals) with just the regular tightness as expected, but overcome with normal force of a 15cm shifter (no heat or penetrating oil needed).

 

Unfortunately, the fourth bolt - the starboard-hand one oriented forward - was found to be almost completely stripped, and the limited attempt to shift it finished the job.   It now presents a round hole, which provides no ability to use an Allen key (either 6mm, or the next size up in imperial) to gain the necessary purchase.  The forward-facing location presents  challenges in terms of access needed to drill and tap in an "Easy Out".  Without drilling, the easy-out can not be inserted far enough to gain any useful purchase.  I have applied heat (MAP//Pro torch) as close as possible to the nut head.  I am also soaking the joint (and the whole motor-tube interface area) with PB Blaster (now also anticipating problems with dropping the tube away from the motor assembly).

 

Has anyone faced this problem with a rounded hex-bolt before, and found a solution?

 

Or are there any other tips and trick, hints or suggestions?

 

Thanking you in anticipation, and with kind regards,

 

David

SM#396, Perigee

On-the-hard, Riverside Drive Marina

Whangarei, New Zealand

 

 

 

 

 


Miles
 

Hi Eric,

 

I do the same with my bow thruster but  only once a year.  I have never had any problems.  I also put Silicon grease on the shaft.  This makes it slide up and down easily and maybe increases the life of the donuts.

 

The agent in Martinique is Douglas Yacht Services or just DYS.  The form makes you exempt from import duties as well as VAT .  It is worth it if you are spending much on your boat.   In the last year or two, I have come to lean on Douglas Yacht Services for more things, making life easier for me in this time of rapidly changing regulations.  They can do or arrange just about anything.  https://www.douglasyachtservices.fr/ .

 

Miles

 

S/Y Ladybug SM 216

 

 


rossirossix4
 

LanoCote® (now owned by Forespar) is also excellent for this.  Because there is also an ongoing discussion regarding rigging I will leave a similar note in that thread.

Bob    KAIMI  SM429 


Nicolas Klene
 

Hello Eric
Very interesting post thank you ,I shall do that asap , I will look for some of that « neverseize « !
What are the lip seal & donuts you are talking about ? 
Best regards 
Nicolas 
SV DarNico
Amel53 # 471

Le 15 déc. 2021 à 04:02, Eric Freedman <kimberlite@...> a écrit :



Twice a year I put a hose clamp on the bow thruster body and remove the 4 bolts that hold the motor to the thruster.

I drop the thruster and apply a lot wheel bearing grease to the bearing in the motor and then clean the

motor spline and bow thruster  female portion. I put WWW.NEVERSEIZEPRODUCTS.COM on both sections and clean the bolts and apply neverseeze. The bolts always come out easily and the thruster drops out rapidly.

 

 

If you are so inclined, you can also replace the lip seal and the donuts at the same time.

Fair Winds

Eric

Kimberlite Amel Super Maramu #376

 

 

 

From: main@AmelYachtOwners.groups.io On Behalf Of David Vogel
Sent: Tuesday, December 07, 2021 3:25 PM
To: main@AmelYachtOwners.groups.io
Subject: Re: [AmelYachtOwners] Bowthruster - damaged hex-nut [count on drilling out that bolt and re-tapping the hole + TORX]

 

Thanks Chris,

 

All good info.  And, having spent already 2 days on this problem with no meaningful progress, it looks like this issue is not going to be solved in the day of so of slack I have in the schedule for this haul-out.

 

And with more to add to the mix, from other interested and assisting parties, is a suggestion to replace the HEX bolts with TORX, as these are less prone to slippage and damage.

 

https://www.mcmaster.com/torx-bolts/drive-style~torx/

 

 

 

From: <main@AmelYachtOwners.groups.io> on behalf of Chris Doucette <amaroksailing@...>

Reply-To: <main@AmelYachtOwners.groups.io>

Date: Wednesday, 8 December 2021 at 8:46 am

To: "main@AmelYachtOwners.groups.io Group Moderators" <main@amelyachtowners.groups.io>

Subject: Re: [AmelYachtOwners] Bowthruster - hex-nut securing he motor to down-tube is stripped out

 

Hi David,

 

I have done a lot of work on the bow thruster these last few months..  In Fact I have rebuilt the entire thing inclusive of the motor bearings.  Basically, count on drilling out that bolt and re- tapping the hole..  It really does not matter if it ends up 9mm vs the original 8mm. But first- get it drilled out. You might have to find a short 8mm drill bit with a right angle drill adapter. Those steel screws go into a brass fitting inside the bow thruster shaft.  It  is what you will tap eventually. Replace the bolts with quality 316 SS bolts, with copious anti-seize. 

 

Once you get it all out- be sure that the bearing in the base of the motor is going to be shot! I took everything appart in the motor also to change the bearings and snap washers, cleaned, brushed off rust, chemically treated the rust, and sealed that large steel base with epoxy and paint.  It looks like new and will not rust as it did. Re-tapped all the screw holes in the brass part. Almost all done here - bow thruster painting is underway and then assembling. 

 

Chris

 

Amarok, SM 385 

 

 

 

On Mon, Dec 6, 2021 at 8:10 PM David Vogel <david.vogel@...> wrote:

Greetings fellow Amelians,

 

Requesting help with a 'small' problem.  After an extended service interval (>3-years since last service of the Bowthuster by AMEL MQ, the unwanted delay due to cruising French Polynesia in COVID times, closed borders, and so on), we're now securely in NZ, primarily for the purposes of attending to long-overdue rounds of routine maintenance - including as a high priority the Bowthruster and C-Drive.

 

Three of the four 6mm hex-bolts that secure the bowthruster motor to the fiberglass (?) torque-tube have been removed without undue problems - desite some rust clearly evident (due I think to the aging neoprene compression seals) with just the regular tightness as expected, but overcome with normal force of a 15cm shifter (no heat or penetrating oil needed).

 

Unfortunately, the fourth bolt - the starboard-hand one oriented forward - was found to be almost completely stripped, and the limited attempt to shift it finished the job.   It now presents a round hole, which provides no ability to use an Allen key (either 6mm, or the next size up in imperial) to gain the necessary purchase.  The forward-facing location presents  challenges in terms of access needed to drill and tap in an "Easy Out".  Without drilling, the easy-out can not be inserted far enough to gain any useful purchase.  I have applied heat (MAP//Pro torch) as close as possible to the nut head.  I am also soaking the joint (and the whole motor-tube interface area) with PB Blaster (now also anticipating problems with dropping the tube away from the motor assembly).

 

Has anyone faced this problem with a rounded hex-bolt before, and found a solution?

 

Or are there any other tips and trick, hints or suggestions?

 

Thanking you in anticipation, and with kind regards,

 

David

SM#396, Perigee

On-the-hard, Riverside Drive Marina

Whangarei, New Zealand

 

 

 

 

 


--
Nicolas Klene
DarNico
SM2K # 471
In Marseille


Bill Kinney
 

Nicolas,

The lip seal and “donuts” are the seals that keep the ocean from coming in where the thruster shaft goes down through the hull.  They are critical maintenance items and should be changed every year—two at the most—to avoid unexpected leaks.  These times are not governed by sailing hours since the failure mode is when the foam rubber in the donut seals compresses and hardens.  This reduces its ability to properly maintain a seal.

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL, USA


Bill Kinney
 

David,

There is nothing bad about changing to TORX head bolts for this, but the ability to exert torque on the head really is not the issue.  If the bolts are kept well greased (or otherwise treated) and exercised regularly (every year or two) there is never any reason that they should be more than barely tight.  When well maintained, they will always come out without a struggle.  It’s only when rust and corrosion take over that they get hopelessly difficult!

All of the Amel thrusters have an excellent system for keeping these bolts in place doing their job even if they are only finger tight.  The exact way this was accomplished varied, depending on the build date. 

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL, USA


Nicolas Klene
 


Thank you Bill
Merry Christmas 
Nicolas 
SM471,DarNico
Marseille

Le 21 déc. 2021 à 19:55, Bill Kinney <cruisingconsulting@...> a écrit :

Nicolas,

The lip seal and “donuts” are the seals that keep the ocean from coming in where the thruster shaft goes down through the hull.  They are critical maintenance items and should be changed every year—two at the most—to avoid unexpected leaks.  These times are not governed by sailing hours since the failure mode is when the foam rubber in the donut seals compresses and hardens.  This reduces its ability to properly maintain a seal.

Bill Kinney
SM160, Harmonie
Fort Lauderdale, FL, USA

--
Nicolas Klene
DarNico
SM2K # 471
In Marseille