Re: Keel Bolt Torque

[Allen Perrins]

Hi

On my standard keel NS 30C there are five bolts.
The center three are one inch diameter. The other two
are 3/4 inch diameter. Hence the nut size difference.
Don't know what the factory spec. was for torque.


Al



-----Original Message-----
>From: Ray & Vida Barrick <cr...@mercator.ca>
>Sent: Apr 21, 2012 2:42 PM
>To: INA International Nonsuch Association <ina-nonsuch-di...@googlegroups.com>
>Subject: Keel Bolt Torque
>
>I have a 30 shoal draft and was hoping someone would know the correct torque for the nuts on the keel bolts. There are two nut sizes (why?) 1 1/4" and 1 5/8".
>
>Thanks
>
>Ray Barrick
>MERCATOR 30C
>Toronto ON
>
>Sent from my iPad

[STEVE BOSCO]

I did get sockets and large breaker bar and could not budge them. Must be alot of torque!

sb

---

From: Allen Perrins <barb...@earthlink.net>
To: ina-nonsuch-di...@googlegroups.com
Sent: Sun, April 22, 2012 9:55:11 AM
Subject: Re: Keel Bolt Torque

[ebe...@verizon.net]

 From a Nonsuch Newsletter dated March 1994

Keelbolt torque:

      1" bolts to 350 ft. lbs.
     
      3/4" bolts to 175 ft. lbs.

 

Earle (Neil) Beasley
470 Wethersfield St.
Rowley, MA 01969

Cell 978-857-7866

[Ray & Vida Barrick]

Thanks Earle. 

Ray Barrick

Sent from my iPhone

[Phil Gow, 30C #125 Lily Pad, Sausalito, CA]

Has anyone torqued their keelbolts? 

175 and 350 footpounds! Wow!

My (friends) torque wrench is hefty but only goes to 200 - I'll be looking for something bigger....!

[Allen Perrins]

Hi

The best time to torque the bolts is at the end of winter storage before launch.

Also tighten at end of haul out when they are long from a summer in the warm (?) 

They are long because of thermal expansion. (make the physics work for you !)

Fabricate a "T" bar wrench to fit the socket used. Make the "T" as a "t" so that 

the end is available for a torque wrench to be used.

Al

Formerly Barbcat,  NS 30C

-----Original Message-----
From: "Phil Gow, 30C #125 Lily Pad, Sausalito, CA"
Sent: Mar 5, 2019 10:53 AM
To: INA Nonsuch Discussion Group
Subject: Re: Keel Bolt Torque

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[Tim in STL]

That is some hefty torque.  There are torque wrench "multipliers" available, they are very expensive, but some rental companies have them.  It would be best to read up on how to properly re-torque bolts.  It has been quite awhile since I was doing that in the service, but it was not just putting a wrench on the nut and clicking the torque wrench.

Tim in STL

White O'morn NS26U #216

Harbor Point Yacht Club

West Alton, MO  

[Douglas Hodgkins]

Years ago when we had our NS30 I called the factory (which was still open at the time) about this issue.  As I recall I believe they recommended 150 ft lbs and they remarked that beyond that amount you're just compressing the fiberglass.  We did this every season and got anywhere from a quarter turn to a half turn on each, depending on how hard we sailed the boat.  

Doug Hodgkins

Naiad 18 SKIMMER

[Bill Spencer]

Also years ago I did the same thing and was told that there was no official torque spec. Later when I asked Mark Ellis and he said the same thing.  "Just get them as tight as you can" was the answer.

Bill Spencer - LIONHEART, NS30U 352 Hyde Park, NY

[Mark Richards]

If you know someone with a 3/4" drive torque wrench ours goes to 600 ft pounds.  If they have a torque wrench they likely have a 3/4" drive socket set also which would have the correct size sockets.

I remember seeing a post on a sailing forum regarding keel bolts and the fellow had taken the keel off and the keel bolts were corroded to about a 1/4" diameter in one spot.  After looking around on sailing forums and I believe in one of the responses to that post it was mentioned that the corrosion was likely due to grounding issues with the boat.

So after seeing that post, I would likely be inclined to remove the keel if I was able to turn the nuts very far.

Mark Richards

FatCat, 30C

Sarnia Ontario

[Phil Gow, 30C #125 Lily Pad, Sausalito, CA]

Thanks all, very interesting!

Keel bolts were loose when I bought LilyPad. Had keel dropped, had everything cleaned up, bolts were all good, boat yard ground out flat spaces on a couple of the fore bolt locations (!!!HMMMM!!!) for new fabricated washer/pads and reassembled and torqued it all down. Want to rotate a couple of the square spacers so they are parallel/aligned fore/aft.

[newelljc9]

Do not forget the fate of CHEEKI RAFIKI and her crew.

John Newell

Mascouche 26#1

Toronto

On Sunday, April 22, 2012 at 9:55:07 AM UTC-4, Allen Perrins wrote:

[Ernie Abugov N22 - #56 "Moustaches" Toronto]

John -

I am not absolutely certain as to why you bring up CHEEKI RAFIKI, actually. That sad vessel had, I believe, suffered a fair whack of previous keel and underbelly damage (collisions, hard groundings, etc.) and was very compromised, long before it even crossed over to race. Consequently, in poor sea conditions, the keel fell off.

Are you saying that "if it ain't broke (seemingly), don't fix it", meaning if there is no leak and nothing, really, to suggest a problem, don't, routinely, futz with these bolts ?? 

Or ...  are you suggesting that, yes, at a given interval, one should tighten up the bolts ?

Otherwise, less than 8 weeks to launch - Wahooo !!

Ernie A. in Toronto

[Phil Gow, 30C #125 Lily Pad, Sausalito, CA]

Mine was glued back on with 3M 5200.

It's NEVER comming off!!!

[John Barbour - Nature 26U Toronto]

The Nonsuch newsletter recommends using 175 and 350 ft-lb torques on the 3/4 and 1 inch stud bolts. With these torques, the stress on both bolts would be about 35,000 psi.  For a standard mild steel bolt 36,000 psi is its minimum yield strength.  A bolt torqued above its yield strength stretches permanently and loses a lot of its clamping force. I expect the torques given in the newsletter should be the absolute maximum load applied. Personally, I wouldn’t even go that high.  Does anyone know what material was used for the bolts?

John Barbour

Nature, 26 U Toronto

[Thor Powell Mariner's Cat V - 26C - North Channel]

The values of 175 and 350 are way too high. See attached. My 26 has stainless bolts, not sure what kind of stainless.  They are into the lead. The keel is 5200 on as well.  

[John Barbour - Nature 26U Toronto]

A typical stainless steel bolt would be 18-8 (304) material which has a minimum yield strength of 20,000 psi. So the torque  values would be lower that those for a 36.000 psi yield mild steel bolt. General industry practice is to torque a bolt to 50% of its yield strength. I expect this standard would apply here? For  3/4" and 1" mild steel bolts this would give 90 and 180 ft-lb torques. Stainless bolts would have proportionally less torque values. The wide fiberglass joint must flex in service so I can see why  the 1994 Nonsuch newsletter recommends checking the bolt torques during annual spring maintenance. The newsletter's maintenance list is pretty comprehensive, Attached is a copy..