Peter,
I went through the same process and have on many boats. Some we
replaced the keel and some we re-torqued due too loose bolts, but
there was always very good advice from keel specialist involved.
Brendan is giving great advice on do not remove your keel unless you
are replacing it or have found damage where you need to remove the
keel to fix it or the hull.
As for removing keel bolt nuts to re-tighten them this is again very
dangerous unless there is a reason. If you see damage, lots of rust,
have a leak, or one is loose. Then have a surveyor check it out
before you just remove and replace or re-torque nuts.
Also tightening them beyond their specific torque will cause more
damage. Lug nuts on a car are Grade 8 bolts, which are a lot higher
tensile strength then Stainless Steel. What stainless are our keel
bolts, no one has told me, I bet they are 304 but would not torque on
a guess.
I felt the same way when I purchased my Express and think about it
every year I look at the bilge during the winter.
A couple of thinks you can do that help are; keep the bilge dry,
always look for movement at the keel joint and around the bolt
washers. And never ever use a cleaner in your bilge that will touch
your bolts. If you see that much rust have a surveyor check it out.
:: The keel bolts are integral to the keel and should not
:: (can not) be removed. Also do not remove your keel from
:: the hull simply to "check" the keel bolts--you may do
:: more damage than good.
::
:: However, they should be inspected and tightened
:: periodically, and the nuts and washers can be renewed.
::
:: Refreshing keel bolts involves removing the nuts (one at
:: a time), cleaning the threads and area around threads as
:: best possible. Inspect as you can, add polysulfide
:: underneath the washer and replace the nuts (without
:: lubricant).
::
:: Do not overtighten keel bolts--they do not need a
:: cheater bar to tighten. Standard torque specification
:: for 1/2" stainless bolts is 45 ft/lbs, which is not
:: super tight (car lugnuts are generally specified to
:: around 90 ft/lbs). Overtightening is more likely to lead
:: to bolt failure than undertightening.
::
:: In the fleet, only one boat has suffered a keel bolt
:: failure. After researching this issue, it seems best to
:: trust your keel bolts but also: never stand under a
:: hoisted boat.