What is the theory behind loosening the bolts before re-tightening?
Gary
"liberty"
---- Ken Heaton via CnC-List <[email protected]> wrote:
> Hello Ron,
>
>
> 1. What are the torque values that you’ve used?
>
>
> 3/4" Keel Bolt (aft) takes a 1-1/8" Socket, Torque to 250 lbs.
>
> 1" Keel Bolt (forward) takes 1-1/2" Deep Socket, Torque to 350 lbs.
>
> 1 1/8" Keel Bolt takes 1-13/16" Socket, Torque to 400 lbs.
>
> 1 1/4" Keel Bolt takes 1-7/8" Socket, Torque to 450 lbs.
>
> 1 1/2" Keel Bolts take 2-1/4" Socket, Torque to 600 lbs.
>
>
> 2. Did you back off the nuts and lubricate?
>
>
> Yes, one at a time. Decrease torque values by 10 % We snick up on the final
> torque values in steps, doing all the bolts, then retourquing to a higher
> value, then repeat until you get to the final values listed above.
>
>
> 3. If so, what did you use for lubrication?
>
>
> We lubed them with Tef Gel. The function of Tef-Gel in eliminating seizing
> galling and friction welding of stainless steel, inconel, and other nickel
> alloys.
>
>
> Tef-Gel applied to both mating surfaces of nuts and bolts or threaded holes
> and bolts leaves a layer of 40% solid PTFE within the thread interface,
> which works as friction barrier. Tef-Gel, which contains 0% volatile
> solvents, will no evaporate, cold flow, or dry out, giving protection many
> years later when hardware must be dissembled.
>
>
> http://us.binnacle.com/product_info.php?products_id=8658
>
>
> Ken H.
>
> On 26 April 2017 at 09:50, Ron Ricci via CnC-List <[email protected]>
> wrote:
>
> > A few months ago, there was a discussion of rust stains and weeps of water
> > appearing on the keel. My first thought had been that water from the bilge
> > leaked around the keel bolts when the boat is on the hard. I had the
> > boatyard do some exploration. They found a void in the keel that
> > apparently filled with water. The void appeared threaded and may have been
> > used to lift the keel. This all can be seen at: https://1drv.ms/f/s!AhpB-
> > lul9d5YpQkMDs5DeOkS73p2. Continued inspection found that there was no
> > water leaking down from the bilge.
> >
> >
> >
> > While my boat is out of the water with the mast out, I’m going to torque
> > the keel bolts. The C&C website lists torque values for ½” (80 ft-lbs), ¾”
> > (250 ft-lbs) and 1” (350 ft-lbs). The 37+ may have another larger size
> > bolt. I don’t know where these came from but found something similar
> > attributed to an employee of Mars Metal (keel manufacturer?). Can any
> > other owners confirm a few things?
> >
> >
> >
> > 1. What are the torque values that you’ve used?
> >
> > 2. Did you back off the nuts and lubricate?
> >
> > 3. If so, what did you use for lubrication?
> >
> >
> >
> > Regards,
> >
> > *Ron*
> >
> > Ron Ricci
> >
> > S/V Patriot
> >
> > C&C 37+
> >
> > Bristol, RI
> >
> > [email protected]
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
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> >
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> >
> >
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