Stus-List Re: Hydraulic backstay adjuster pressure?

[Bill Coleman via CnC-List]

Just found this in my Sailtec documentation,

 

Pressure (PSI) Reading   (#) TensionCyl. DiameterCyl. Bore

-08 size matches.6:1.00 psi 1.50"
1.002

-10 size matches 1:1.00 psi 1.75"
1.250

-12 size matches 1:1.30 psi 2.00"
1.500

-17 size matches 1:1.76 psi 2.25"
1.750

-22 size matches 1:2.20 psi 2.75"
2.000

 

So it does look like the -10 is Hydraulic pressure = Tensile #

I learn something every day. I have two  -10 cylinders on a split backstay,
so I guess 1,000# pressure = 2,000 tensile#. 

 

They don't make it easy to find all this stuff.

 

Bill Coleman

Entrada, Erie, PA

 

 

 

From: Jeffrey A. Laman via CnC-List [mailto:cnc-list@cnc-list.com] 
Sent: Monday, April 19, 2021 11:07 AM
To: Stus-List
Cc: Jeffrey A. Laman
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?

 

Hi All.  Also wanted to comment on the pressure question.  As I noted in my
post about the NavTec - 10 failure, I have been examining all the issues
that I more or less ignored or was happily ignorant of till now.  One item
was to determine the yield and breaking load on my backstay and correlating
backstay shortening to load.  If you do a little geometry and have knowledge
of stress/force/strain/elongation, it is a fairly simple determination (I am
a structural engineer).  Others have provided photos of simple shortening
measure devices, which I now intend to make and install.  If others have
photos, please share!  But, one comment on pressure and force -- the
pressure on the hydraulic backstay is directly related to force.  So, if I
trouble myself to read it, I will pay much more attention to the pressure on
the gauge right in front of my face.  At the moment, I don't recall what I
read -- either NavTec or SailTec, or maybe both, 1000 psi = 1000 lbs force.
The NavTec - 10 has a relief valve set to 4000 lbs.  SailTec - 10 is 4750
lbs.  Others with more knowledge may have more definitive information.  Long
story but I received the wrong SailTec - 10 the first time -- a custom unit
for J105s that has a pressure relief at 3000 lbs.

 

Excellent discussion, btw everybody!

 

Jeff L.

 

Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Jeffrey A. Laman via CnC-List]

1981 C  Sorry, got lazy on the signature.
I believe the rods are 7/32 dia
I understand that the rods were made by NavTec, referred to as NAV R505
This is a cold drawn rod from Nitronic 50 (22-13-5)
Fu = 200,000 psi
7/32" dia = 0.0375 in^2
Breaking force = Fu x A =  7,500 lbs

Jeff Laman
1981 C "Harmony"
Ludington, MI


From: Bill Coleman via CnC-List 
Sent: Monday, April 19, 2021 12:09 PM
To: 'Stus-List' 
Cc: Bill Coleman 
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?


I am not sure the size boat we are talking about, but I think I would have been 
happy to have a relief valve set for 3K.  Seems anything over that and you 
would be pulling the boat away from the front of your keel. I do like SailTec, 
and that unit is a great piece.





Bill Coleman

Entrada, Erie, PA





From: Jeffrey A. Laman via CnC-List [mailto:cnc-list@cnc-list.com]
Sent: Monday, April 19, 2021 11:07 AM
To: Stus-List
Cc: Jeffrey A. Laman
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?



Hi All.  Also wanted to comment on the pressure question.  As I noted in my 
post about the NavTec - 10 failure, I have been examining all the issues that I 
more or less ignored or was happily ignorant of till now.  One item was to 
determine the yield and breaking load on my backstay and correlating backstay 
shortening to load.  If you do a little geometry and have knowledge of 
stress/force/strain/elongation, it is a fairly simple determination (I am a 
structural engineer).  Others have provided photos of simple shortening measure 
devices, which I now intend to make and install.  If others have photos, please 
share!  But, one comment on pressure and force -- the pressure on the hydraulic 
backstay is directly related to force.  So, if I trouble myself to read it, I 
will pay much more attention to the pressure on the gauge right in front of my 
face.  At the moment, I don't recall what I read -- either NavTec or SailTec, 
or maybe both, 1000 psi = 1000 lbs force.  The NavTec - 10 has a relief valve 
set to 4000 lbs.  SailTec - 10 is 4750 lbs.  Others with more knowledge may 
have more definitive information.  Long story but I received the wrong SailTec 
- 10 the first time -- a custom unit for J105s that has a pressure relief at 
3000 lbs.



Excellent discussion, btw everybody!



Jeff L.





From: Edd Schillay via CnC-List 
Sent: Sunday, April 18, 2021 3:04 PM
To: Stus-List 
Cc: Edd Schillay 
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?



Bruce,



You may find this article interesting: 
https://www.sailingworld.com/getting-most-from-your-backstay/<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sailingworld.com%2Fgetting-most-from-your-backstay%2F=04%7C01%7C%7Ca538f089ff564ba2ae6b08d9034daa01%7C84df9e7fe9f640afb435%7C1%7C0%7C637544454357973714%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=EgTppT2C4rrGrgPGEUI2%2BZFqgP62yKmf4UV4oTCvFVg%3D=0>

All the best,



Edd





Edd M. Schillay

Captain of the Starship Enterprise

C 37+ | Sail No: NCC-1701-B

Venice Yacht Club | Venice Island, FL




















On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List 
mailto:cnc-list@cnc-list.com>> wrote:



Hello all



 With all of the discussions about hydraulic backstay adjusters, and mine being 
fixed (finally), where do most of you keep and use the pressure?  At the dock 
vs. sailing and under what conditions?



Thanks!



Bruce Whitmore

1994 C 37/40+

Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   
https://www.paypal.me/stumurray<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.paypal.me%2Fstumurray=04%7C01%7C%7Ca538f089ff564ba2ae6b08d9034daa01%7C84df9e7fe9f640afb435%7C1%7C0%7C637544454357983668%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=X7C%2FzuPJsJi7hey8BhPEP8YAwOmzSyELhfXEUeKmpcY%3D=0>
  Thanks - Stu


Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Jeffrey A. Laman via CnC-List]

Yes, there you go -- pressure to gauge.
Thanks for making clear to all that psi and kpsi ( = 1000 psi) are NOT force, 
but internal oil pressure.
This link is not for the series 6, however.  My data sheet, which is on board 
the boat right now, I believe indicated 1000 psi = 1000 lbs.  If I remember, 
i'll check it when I go to the boat.  It's possible not all NavTec - 10s are 
the same -- depending on series -- maybe.

Jeff L.
1981 C "Harmony"
Ludington, MI




From: Dennis C. via CnC-List 
Sent: Monday, April 19, 2021 12:39 PM
To: Stus-List 
Cc: Dennis C. 
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?

Um, sorta.  Yes, it is related but not 1:1.  The gauge shows psi in the 
cylinder.  That is NOT pounds tension or pull on the backstay.  You need to 
take into account the pressure area of the piston.  The pressure area of the 
piston on a Navtec 10 series is 1.160 square inches.  (Pressure area is the 
area of the piston minus the area of the 0.5 inch diameter rod).

Go here:

https://drive.google.com/file/d/1-jO5DG6XmclSUhB3S5MLQhFG7drS2Ctf/view?usp=sharing<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F1-jO5DG6XmclSUhB3S5MLQhFG7drS2Ctf%2Fview%3Fusp%3Dsharing=04%7C01%7C%7C60aa584fba6d47e0016908d90351d19f%7C84df9e7fe9f640afb435%7C1%7C0%7C637544472206078660%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=tDykzdahHV0h3I%2BJe6%2BP7N%2FCRV%2B8E1NEKLShM5vXyO8%3D=0>

Note that for a NavTec 10 adjuster, 1000 psi on the gauge is 550 kgf or about 
1200 pounds pull.  A decent rule of thumb would be 1.2 times gauge psi = pounds 
pull for a NavTec 10.

I still find a batten with colored tape to be easier.

https://drive.google.com/file/d/15VQF_A2X3ZNBW5ZPueAaJ9mw23X8YsQH/view?usp=sharing<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdrive.google.com%2Ffile%2Fd%2F15VQF_A2X3ZNBW5ZPueAaJ9mw23X8YsQH%2Fview%3Fusp%3Dsharing=04%7C01%7C%7C60aa584fba6d47e0016908d90351d19f%7C84df9e7fe9f640afb435%7C1%7C0%7C637544472206078660%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=XuYZLtq35zJf2uQR3htAUIOWiri04uesUW8EUnaZn4A%3D=0>

  --
Dennis C.
Touche' 35-1 #83
Mandeville, LA

On Mon, Apr 19, 2021 at 10:07 AM Jeffrey A. Laman via CnC-List 
mailto:cnc-list@cnc-list.com>> wrote:
 But, one comment on pressure and force -- the pressure on the hydraulic 
backstay is directly related to force.  So, if I trouble myself to read it, I 
will pay much more attention to the pressure on the gauge right in front of my 
face.  At the moment, I don't recall what I read -- either NavTec or SailTec, 
or maybe both, 1000 psi = 1000 lbs force.

Jeff L.





Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Dennis C. via CnC-List]

Um, sorta.  Yes, it is related but not 1:1.  The gauge shows psi in the
cylinder.  That is NOT pounds tension or pull on the backstay.  You need to
take into account the pressure area of the piston.  The pressure area of
the piston on a Navtec 10 series is 1.160 square inches.  (Pressure area is
the area of the piston minus the area of the 0.5 inch diameter rod).

Go here:

https://drive.google.com/file/d/1-jO5DG6XmclSUhB3S5MLQhFG7drS2Ctf/view?usp=sharing

Note that for a NavTec 10 adjuster, 1000 psi on the gauge is 550 kgf or
about 1200 pounds pull.  A decent rule of thumb would be 1.2 times gauge
psi = pounds pull for a NavTec 10.

I still find a batten with colored tape to be easier.

https://drive.google.com/file/d/15VQF_A2X3ZNBW5ZPueAaJ9mw23X8YsQH/view?usp=sharing

  --
Dennis C.
Touche' 35-1 #83
Mandeville, LA

On Mon, Apr 19, 2021 at 10:07 AM Jeffrey A. Laman via CnC-List <
cnc-list@cnc-list.com> wrote:

>  But, one comment on pressure and force -- the pressure on the hydraulic
> backstay is directly related to force.  So, if I trouble myself to read it,
> I will pay much more attention to the pressure on the gauge right in front
> of my face.  At the moment, I don't recall what I read -- either NavTec or
> SailTec, or maybe both, 1000 psi = 1000 lbs force.
>
> Jeff L.
>
> --
>
>
>
>
Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Bill Coleman via CnC-List]

I am not sure the size boat we are talking about, but I think I would have
been happy to have a relief valve set for 3K.  Seems anything over that and
you would be pulling the boat away from the front of your keel. I do like
SailTec, and that unit is a great piece.

 

 

Bill Coleman

Entrada, Erie, PA

 

 

From: Jeffrey A. Laman via CnC-List [mailto:cnc-list@cnc-list.com] 
Sent: Monday, April 19, 2021 11:07 AM
To: Stus-List
Cc: Jeffrey A. Laman
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?

 

Hi All.  Also wanted to comment on the pressure question.  As I noted in my
post about the NavTec - 10 failure, I have been examining all the issues
that I more or less ignored or was happily ignorant of till now.  One item
was to determine the yield and breaking load on my backstay and correlating
backstay shortening to load.  If you do a little geometry and have knowledge
of stress/force/strain/elongation, it is a fairly simple determination (I am
a structural engineer).  Others have provided photos of simple shortening
measure devices, which I now intend to make and install.  If others have
photos, please share!  But, one comment on pressure and force -- the
pressure on the hydraulic backstay is directly related to force.  So, if I
trouble myself to read it, I will pay much more attention to the pressure on
the gauge right in front of my face.  At the moment, I don't recall what I
read -- either NavTec or SailTec, or maybe both, 1000 psi = 1000 lbs force.
The NavTec - 10 has a relief valve set to 4000 lbs.  SailTec - 10 is 4750
lbs.  Others with more knowledge may have more definitive information.  Long
story but I received the wrong SailTec - 10 the first time -- a custom unit
for J105s that has a pressure relief at 3000 lbs.

 

Excellent discussion, btw everybody!

 

Jeff L.

 

  _  

From: Edd Schillay via CnC-List 
Sent: Sunday, April 18, 2021 3:04 PM
To: Stus-List 
Cc: Edd Schillay 
Subject: Stus-List Re: Hydraulic backstay adjuster pressure? 

 

Bruce, 

 

You may find this article interesting:
https://www.sailingworld.com/getting-most-from-your-backstay/
<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sailin
gworld.com%2Fgetting-most-from-your-backstay%2F=04%7C01%7C%7Cd3bfbd243a
ce446e7faa08d9029cd2fa%7C84df9e7fe9f640afb435%7C1%7C0%7C63754369
4834999454%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBT
iI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=smkRPe%2FC7SoZvMsQlt7WcZs5QqU7SNdPAHU
nv0jHi2A%3D=0>  


All the best,

 

Edd

 

 

Edd M. Schillay

Captain of the Starship Enterprise

C 37+ | Sail No: NCC-1701-B

Venice Yacht Club | Venice Island, FL

 





















 






 

On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List
 wrote:

 

Hello all 

 

 With all of the discussions about hydraulic backstay adjusters, and mine
being fixed (finally), where do most of you keep and use the pressure?  At
the dock vs. sailing and under what conditions?  

 

Thanks!

 

Bruce Whitmore 

1994 C 37/40+

Thanks to all of the subscribers that contributed to the list to help with
the costs involved.  If you want to show your support to the list - use
PayPal to send contribution --   https://www.paypal.me/stumurray
<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.paypal
.me%2Fstumurray=04%7C01%7C%7Cd3bfbd243ace446e7faa08d9029cd2fa%7C84df9e7
fe9f640afb435%7C1%7C0%7C637543694834999454%7CUnknown%7CTWFpbGZsb
3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000
=FQbJL0AbzD%2FsK2R9lqD%2Bsmu7EGNJGm7cTKs7uo6UfRY%3D=0>
Thanks - Stu

 

Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Joel Aronson via CnC-List]

OK, who wants to throw babystay tension into the discussion of sail shape?

Joel

On Mon, Apr 19, 2021 at 12:04 PM CHARLES SCHEAFFER via CnC-List <
cnc-list@cnc-list.com> wrote:

> Hi all,
> IIRC, Our boat has a -10 rod capable of 10,000# load.  The owners manual
> states not to exceed 40% of rod strength on the backstay hydraulic ram so
> our setup relieves around 3500 and we stay below that.  We have a remote
> pump panel and the relief is adjustable.  I set it myself after I had mine
> rebuilt by a local Ram shop.  I believe excessive pressure will initially
> stretch the rod and more pressure will cause it to break.   On board the
> boat, we adjust backstay by looking at the sails and only use the gauge as
> a safety reference.   A batten is taped to the ram to indicate repeatable
> settings.
>
> FWIW, Something I keep experimenting with:  It's important to set the
> headstay and backstay length properly so the backstay works the way you
> want.  It's part of tuning and done after the mast is centered and the
> shrouds are tensioned fully.  In lighter air, you may want to bend the mast
> a little and flatten the mainsail before tightening the headstay
> excessively.   In stronger winds, you may want the headstay to tighten
> before flattening the main.  The PO used to add a 2" toggle to the headstay
> for light winds to lengthen the headstay and remove it for winds over 15
> knots.  This reduces the rake slightly and gives the backstay slightly more
> leverage and quicker response in higher winds and you get the right shape
> before bottoming out or exceeding thresholds.
>
> Chuck Scheaffer 1989 C 34R, Pasadena Md
>
>
> On 04/19/2021 11:06 AM Jeffrey A. Laman via CnC-List <
> cnc-list@cnc-list.com> wrote:
>
>
> Hi All.  Also wanted to comment on the pressure question.  As I noted in
> my post about the NavTec - 10 failure, I have been examining all the issues
> that I more or less ignored or was happily ignorant of till now.  One item
> was to determine the yield and breaking load on my backstay and correlating
> backstay shortening to load.  If you do a little geometry and have
> knowledge of stress/force/strain/elongation, it is a fairly simple
> determination (I am a structural engineer).  Others have provided photos of
> simple shortening measure devices, which I now intend to make and install.
> If others have photos, please share!  But, one comment on pressure and
> force -- the pressure on the hydraulic backstay is directly related to
> force.  So, if I trouble myself to read it, I will pay much more attention
> to the pressure on the gauge right in front of my face.  At the moment, I
> don't recall what I read -- either NavTec or SailTec, or maybe both, 1000
> psi = 1000 lbs force.  The NavTec - 10 has a relief valve set to 4000 lbs.
> SailTec - 10 is 4750 lbs.  Others with more knowledge may have more
> definitive information.  Long story but I received the wrong SailTec - 10
> the first time -- a custom unit for J105s that has a pressure relief at
> 3000 lbs.
>
> Excellent discussion, btw everybody!
>
> Jeff L.
>
>
> ------
> *From:* Edd Schillay via CnC-List 
> *Sent:* Sunday, April 18, 2021 3:04 PM
> *To:* Stus-List 
> *Cc:* Edd Schillay 
> *Subject:* Stus-List Re: Hydraulic backstay adjuster pressure?
>
> Bruce,
>
> You may find this article interesting:
> https://www.sailingworld.com/getting-most-from-your-backstay/
> <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sailingworld.com%2Fgetting-most-from-your-backstay%2F=04%7C01%7C%7Cd3bfbd243ace446e7faa08d9029cd2fa%7C84df9e7fe9f640afb435%7C1%7C0%7C637543694834999454%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=smkRPe%2FC7SoZvMsQlt7WcZs5QqU7SNdPAHUnv0jHi2A%3D=0>
>
>
> All the best,
>
> Edd
>
>
> Edd M. Schillay
> Captain of the Starship Enterprise
> C 37+ | Sail No: NCC-1701-B
> Venice Yacht Club | Venice Island, FL
>
>
>
>
>
>
>
>
>
>
>
> On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List <
> cnc-list@cnc-list.com> wrote:
>
> Hello all
>
>  With all of the discussions about hydraulic backstay adjusters, and mine
> being fixed (finally), where do most of you keep and use the pressure?  At
> the dock vs. sailing and under what conditions?
>
> Thanks!
>
> Bruce Whitmore
> 1994 C 37/40+
> Thanks to all of the subscribers that contributed to the list to help with
> the costs involved.  If you want to show your support to the list - use
> PayPal to send contribution --https://www.paypal.me/stumurray
> <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.paypal.me%2Fstum

Stus-List Re: Hydraulic backstay adjuster pressure?

[CHARLES SCHEAFFER via CnC-List]

Hi all,
IIRC, Our boat has a -10 rod capable of 10,000# load.  The owners manual states 
not to exceed 40% of rod strength on the backstay hydraulic ram so our setup 
relieves around 3500 and we stay below that.  We have a remote pump panel and 
the relief is adjustable.  I set it myself after I had mine rebuilt by a local 
Ram shop.  I believe excessive pressure will initially stretch the rod and more 
pressure will cause it to break.   On board the boat, we adjust backstay by 
looking at the sails and only use the gauge as a safety reference.   A batten 
is taped to the ram to indicate repeatable settings.

FWIW, Something I keep experimenting with:  It's important to set the headstay 
and backstay length properly so the backstay works the way you want.  It's part 
of tuning and done after the mast is centered and the shrouds are tensioned 
fully.  In lighter air, you may want to bend the mast a little and flatten the 
mainsail before tightening the headstay excessively.   In stronger winds, you 
may want the headstay to tighten before flattening the main.  The PO used to 
add a 2" toggle to the headstay for light winds to lengthen the headstay and 
remove it for winds over 15 knots.  This reduces the rake slightly and gives 
the backstay slightly more leverage and quicker response in higher winds and 
you get the right shape before bottoming out or exceeding thresholds.

Chuck Scheaffer 1989 C 34R, Pasadena Md


> On 04/19/2021 11:06 AM Jeffrey A. Laman via CnC-List 
>  wrote:
>  
>  
> Hi All.  Also wanted to comment on the pressure question.  As I noted in 
> my post about the NavTec - 10 failure, I have been examining all the issues 
> that I more or less ignored or was happily ignorant of till now.  One item 
> was to determine the yield and breaking load on my backstay and correlating 
> backstay shortening to load.  If you do a little geometry and have knowledge 
> of stress/force/strain/elongation, it is a fairly simple determination (I am 
> a structural engineer).  Others have provided photos of simple shortening 
> measure devices, which I now intend to make and install.  If others have 
> photos, please share!  But, one comment on pressure and force -- the pressure 
> on the hydraulic backstay is directly related to force.  So, if I trouble 
> myself to read it, I will pay much more attention to the pressure on the 
> gauge right in front of my face.  At the moment, I don't recall what I read 
> -- either NavTec or SailTec, or maybe both, 1000 psi = 1000 lbs force.  The 
> NavTec - 10 ha
 s a relief valve set to 4000 lbs.  SailTec - 10 is 4750 lbs.  Others with more 
knowledge may have more definitive information.  Long story but I received the 
wrong SailTec - 10 the first time -- a custom unit for J105s that has a 
pressure relief at 3000 lbs.
>  
> Excellent discussion, btw everybody!
>  
> Jeff L.
>  
>  
> 
> -
> From: Edd Schillay via CnC-List 
> Sent: Sunday, April 18, 2021 3:04 PM
> To: Stus-List 
> Cc: Edd Schillay 
> Subject: Stus-List Re: Hydraulic backstay adjuster pressure?
>  
> Bruce,
>  
> You may find this article interesting:  
> https://www.sailingworld.com/getting-most-from-your-backstay/ 
> https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sailingworld.com%2Fgetting-most-from-your-backstay%2F=04%7C01%7C%7Cd3bfbd243ace446e7faa08d9029cd2fa%7C84df9e7fe9f640afb435%7C1%7C0%7C637543694834999454%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=smkRPe%2FC7SoZvMsQlt7WcZs5QqU7SNdPAHUnv0jHi2A%3D=0
>   
> 
> All the best,
>  
> Edd
>  
>  
> Edd M. Schillay
> Captain of the Starship Enterprise
> C 37+ | Sail No: NCC-1701-B
> Venice Yacht Club | Venice Island, FL
>  
> 
> 
> 
> 
> 
>  
>  
> 
> 
> 
> On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List < 
> cnc-list@cnc-list.com mailto:cnc-list@cnc-list.com > wrote:
> 
> Hello all
>  
>  With all of the discussions about hydraulic backstay adjusters, and mine 
> being fixed (finally), where do most of you keep and use the pressure?  At 
> the dock vs. sailing and under what conditions?  
>  
> Thanks!
>  
> Bruce Whitmore 
> 1994 C 37/40+
> Thanks to all of the subscribers that contributed to the list to help 
> with the costs involved.  If you want to show your support to the list - use 
> PayPal to send contribution --https://www.paypal.me/stumurray 
> https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.paypal.me%2Fstumurray=04%7C01%7C%7Cd3bfbd243ace446e7faa08d9029cd2fa%7C84df9e7fe9

Stus-List Re: Hydraulic backstay adjuster pressure?

[Jeffrey A. Laman via CnC-List]

Hi All.  Also wanted to comment on the pressure question.  As I noted in my 
post about the NavTec - 10 failure, I have been examining all the issues that I 
more or less ignored or was happily ignorant of till now.  One item was to 
determine the yield and breaking load on my backstay and correlating backstay 
shortening to load.  If you do a little geometry and have knowledge of 
stress/force/strain/elongation, it is a fairly simple determination (I am a 
structural engineer).  Others have provided photos of simple shortening measure 
devices, which I now intend to make and install.  If others have photos, please 
share!  But, one comment on pressure and force -- the pressure on the hydraulic 
backstay is directly related to force.  So, if I trouble myself to read it, I 
will pay much more attention to the pressure on the gauge right in front of my 
face.  At the moment, I don't recall what I read -- either NavTec or SailTec, 
or maybe both, 1000 psi = 1000 lbs force.  The NavTec - 10 has a relief valve 
set to 4000 lbs.  SailTec - 10 is 4750 lbs.  Others with more knowledge may 
have more definitive information.  Long story but I received the wrong SailTec 
- 10 the first time -- a custom unit for J105s that has a pressure relief at 
3000 lbs.

Excellent discussion, btw everybody!

Jeff L.


From: Edd Schillay via CnC-List 
Sent: Sunday, April 18, 2021 3:04 PM
To: Stus-List 
Cc: Edd Schillay 
Subject: Stus-List Re: Hydraulic backstay adjuster pressure?

Bruce,

You may find this article interesting: 
https://www.sailingworld.com/getting-most-from-your-backstay/<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.sailingworld.com%2Fgetting-most-from-your-backstay%2F=04%7C01%7C%7Cd3bfbd243ace446e7faa08d9029cd2fa%7C84df9e7fe9f640afb435%7C1%7C0%7C637543694834999454%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=smkRPe%2FC7SoZvMsQlt7WcZs5QqU7SNdPAHUnv0jHi2A%3D=0>

All the best,

Edd


Edd M. Schillay
Captain of the Starship Enterprise
C 37+ | Sail No: NCC-1701-B
Venice Yacht Club | Venice Island, FL










On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List 
mailto:cnc-list@cnc-list.com>> wrote:

Hello all

 With all of the discussions about hydraulic backstay adjusters, and mine being 
fixed (finally), where do most of you keep and use the pressure?  At the dock 
vs. sailing and under what conditions?

Thanks!

Bruce Whitmore
1994 C 37/40+
Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   
https://www.paypal.me/stumurray<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.paypal.me%2Fstumurray=04%7C01%7C%7Cd3bfbd243ace446e7faa08d9029cd2fa%7C84df9e7fe9f640afb435%7C1%7C0%7C637543694834999454%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000=FQbJL0AbzD%2FsK2R9lqD%2Bsmu7EGNJGm7cTKs7uo6UfRY%3D=0>
  Thanks - Stu

Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Don Harben via CnC-List]

Smile. 
When the cabin or head doors do not work, you are bending the boat. 

Some of the C  boat manuals provided big cautions about gauge readings 
redline!

Don



Don Harben
Viking 34

>> Thanks to all of the subscribers that contributed to the list to help with 
>> the costs involved.  If you want to show your support to the list - use 
>> PayPal to send contribution --   https://www.paypal.me/stumurray  Thanks - 
>> Stu
> 
> Thanks to all of the subscribers that contributed to the list to help with 
> the costs involved.  If you want to show your support to the list - use 
> PayPal to send contribution --   https://www.paypal.me/stumurray  Thanks - Stu
Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Dennis C. via CnC-List]

Bruce,

To answer your question, I have no idea.  For many years the gauge on my
adjuster was unreadable.  As part of the recent repair, a new gauge was
installed.  I still have no plans to look at it.

First, the reading is only an indicator.  It shows hydraulic pressure
inside the cylinder.  This NOT the same as tension on the backstay.  For
that, you have to know the diameter of your piston and do some math.

You really should be looking at the sail shapes.  On Touche' we adjust the
tension and take a quick peek at our adjuster position indicator, a dinghy
batten taped to the backstay adjuster.  The batten has colored tape at
intervals in the operating range.  Look here:

https://drive.google.com/file/d/15VQF_A2X3ZNBW5ZPueAaJ9mw23X8YsQH/view?usp=sharing

Zoom in to the top of the batten.  You should be able to see 4 pieces of
colored tape; green (light tension), yellow (moderate tension), red (heavy
tension) and black (OMG, we're going to die!).  These pieces of tape do not
correlate to the gauge pressure in any meaningful way.

We know from experience approximately where to set the bottom of the head
of the ram against the tapes.

At the dock, I leave it set towards the top of the green tape.  I give the
backstay a grab and shake and say "that's about right".  I think that
correlates to 600-800 on the gauge.
-- 
Dennis C.
Touche' 35-1 #83
Mandeville, LA

On Sun, Apr 18, 2021 at 1:06 PM Bruce Whitmore via CnC-List <
cnc-list@cnc-list.com> wrote:

> Hello all
>
>  With all of the discussions about hydraulic backstay adjusters, and mine
> being fixed (finally), where do most of you keep and use the pressure?  At
> the dock vs. sailing and under what conditions?
>
> Thanks!
>
> Bruce Whitmore
> 1994 C 37/40+
> Thanks to all of the subscribers that contributed to the list to help with
> the costs involved.  If you want to show your support to the list - use
> PayPal to send contribution --   https://www.paypal.me/stumurray  Thanks
> - Stu
Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[CHARLES SCHEAFFER via CnC-List]

Good article, thx

> On 04/18/2021 3:04 PM Edd Schillay via CnC-List  
> wrote:
>  
>  
> Bruce,
>  
> You may find this article interesting:  
> https://www.sailingworld.com/getting-most-from-your-backstay/ 
> All the best,
>  
> Edd
>  
>  
> Edd M. Schillay
> Captain of the Starship Enterprise
> C 37+ | Sail No: NCC-1701-B
> Venice Yacht Club | Venice Island, FL
>  
>  
>  
>  
> 
> On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List < 
> cnc-list@cnc-list.com mailto:cnc-list@cnc-list.com > wrote:
> Hello all
>  
>  With all of the discussions about hydraulic backstay adjusters, and mine 
> being fixed (finally), where do most of you keep and use the pressure?  At 
> the dock vs. sailing and under what conditions?  
>  
> Thanks!
>  
> Bruce Whitmore 
> 1994 C 37/40+
> Thanks to all of the subscribers that contributed to the list to help 
> with the costs involved.  If you want to show your support to the list - use 
> PayPal to send contribution --https://www.paypal.me/stumurray  Thanks - 
> Stu
> Thanks to all of the subscribers that contributed to the list to help 
> with the costs involved. If you want to show your support to the list - use 
> PayPal to send contribution -- https://www.paypal.me/stumurray Thanks - Stu
> 
Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Stus-List Re: Hydraulic backstay adjuster pressure?

[Edd Schillay via CnC-List]

Bruce,

You may find this article interesting: 
https://www.sailingworld.com/getting-most-from-your-backstay/ 
 

All the best,

Edd


Edd M. Schillay
Captain of the Starship Enterprise
C 37+ | Sail No: NCC-1701-B
Venice Yacht Club | Venice Island, FL











On Apr 18, 2021, at 2:05 PM, Bruce Whitmore via CnC-List 
 wrote:

Hello all

 With all of the discussions about hydraulic backstay adjusters, and mine being 
fixed (finally), where do most of you keep and use the pressure?  At the dock 
vs. sailing and under what conditions?  

Thanks!

Bruce Whitmore 
1994 C 37/40+
Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu

Thanks to all of the subscribers that contributed to the list to help with the 
costs involved.  If you want to show your support to the list - use PayPal to 
send contribution --   https://www.paypal.me/stumurray  Thanks - Stu