Hi Chris & Josh,
I am not in agreement that keel bolts can only be
tightened while the boat is ashore.
While that is a convenient activity during the
annual haulout period that Eastern boats get, it
is not entirely practical for us on the West
Coast or the lads down south. We might only haul every two or three years.
The technical sheet in the link shows the
theoretical load on a 1" bolt (torque to 350
ft-lbs spec) is ~12,000 lbs. This is more than
the weight of the keel such that it does not
matter whether the keel is supported on the
ground or hanging in the water, the joint is held
firmly together by one keelbolt. The rest are not
required to do anything at this time.
https://www.hobson.com.au/files/technical/utd-gd-torque-tension.pdf
I suggest that the proper procedure for
tightening keelboats be observed whether the boat is in water or in the yard.
For a 1" keelboat to 350 ft-lbs torque:
start with centre nut and take it to 250 ft-lbs,
repeat for other nuts alternating for and aft sequence
remove centre nut and lubricate, retorque to 300
ft-lbs, repeat as for other nuts as above
retorque centre nut to 350 ft-lbs, repeat as for other nuts as above
Then you can a have a beer Chris and reflect on
how fortunate you are to be sailing B.C South
Coast. Anything 100 miles to the east of you is beyond Hope.
:) <VBG>
Cheers, Russ
East side o' Vancouver Island
At 08:15 AM 4/24/2020, you wrote:
Chris,
The prevailing wisdom of this list suggests that
the keel bolts only be torqued while the boat is
resting on its keel, generally about 60% of it's
weight depending on the design. In this way
you are not turning the nuts against the weight
of the keel or even trying to compress the
bedding material. IMO, it is likely that you
will find more movement in the nuts when you retorque on dry land.
I am not familiar with the design of your
particular boat but some boats have keel bolts
which are entirely inaccessible with the mast in
place. Make sure there isn't one (or two) hiding somewhere.
Josh MuckleyÂ
S/V Sea HawkÂ
1989 C&C 37+
Solomons, MD
On Thu, Apr 23, 2020, 20:59 Chris Bennett via
CnC-List <<mailto:cnc-list@cnc-list.com>cnc-list@cnc-list.com> wrote:
Status update: I ended up torquing the keel
bolts. They were not incredibly loose but all of
them needed tightening, two by a turn or more
and the other two by less than a turn. I will
know if this removed the keel movement when the
boat is next hauled out, although I am also
thinking of diving on her to see if I can detect
any wiggle that way (I live in BC and the water
is pretty cold but manageable for a few minutes
with a wet suit - I hope!). I believe that a
very small looseness in a narrow keel root would
result in a fairly noticeable movement at the
tip of a 3 foot keel - even 1/8 inch of movement
over 2 inches width would translate into a
couple of inches at the tip, if I have that
right. So hopefully this was the issue!
I took Drifter for a sail today after rebuilding
the mast step and did not notice any flexing or
movement in the floors or hull (made pencil
marks on the floors and adjacent hull skin and
checked on different tacks). I also checked
the tabbing under the settees on one side and
found it intact, so suspect that the surveyor
may have jumped to conclusions when he said the
hull had been compromised and that was what was causing the keel movement.
Â
 Thanks again to everyone for their suggestions.
ChrisÂ
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