Keel Bolt Rust -
A Rusting Bolt
is a Rusting Bolt is a.....
|I have almost decided
to ignore my keel bolts for another season. See them in the picture
below. Every time I open that shot, I sag. It's painful
to be sure but now looks a bit less so after scraping the bolts
a bit. Even though I dont think my keel will drop, the confidence
here is slightly troubling as well. The comments by Brian Pickton
did give me a bit of solace... just a bit. And Ian's REALLY helped.
235 Keel Bolt Info
Direct from Factory - 5/18/04
You need a total of 5 keel bolts for the F235. 4 bolts will
be the same size, each costing $8.81. The last bolt, which
is the smaller first bolt from the stern is $3.06. Wade
recommends wire brushing each bolt to see what you have.
If you can still fit a socket on there without it rotating,
you should be fine. One note again, Wade has NEVER heard
of a Beneteau keel falling off. If you do attempt to replace
them, it can be done while still in water, one at a time.
If ANY water leaks in, it's time to haul and re-bed the
F235 Total Cost 5 Keel Bolts....................$38.30
with washers from
Beneteau, see below
(4) Part:017541 -
BOLT 20X70 HEX HEAD $8.81 ea.
(1) Part:017542 - BOLT 14X50 HEX HEAD $3.06 ea.
Part:015056 WASHER GALV D22X60X5 $3.99 ea.
(1) Part:015055 WASHER ID16 X OD45X5T $2.87 ea.
Ian Coverdale had some interesting comments regarding
a First 24 and the horribly circumspect keel bolts, probably not unlike
a good many First 235 with water left in the shallow bilge. Please
read below and see Ian's shot of his removed First 24 bolt at left
I recall some debate and
concern amongst potential buyers three years ago when a well known
charter company offered their fleet of fin-keeled Beneteau First 24's
for sale; many had the same fault: very rusty keel bolts. Indeed
the bilges of my boat had clearly been awash for some time and bolt
heads deeply encrusted with rust.
The rusty bolts ...weighed heavily
on my mind recently. So this winter's project was to remove the
keel, have it shot-blasted and new bolts fitted; I've lived with
the doubts for two seasons and now it is time to act!
I have removed the bolts and been
pleased to discover that my concerns were unfounded! Now others
who have the dreaded rusty-bolt syndrome may take comfort from
the attached photograph which shows the threads to be like new
and underneath that rusty head is actually a very sound bolt.
The washer is beyond redemption,
however. The corrosion has clearly come from constantly wet bilges
(leaks around stanchion posts - familiar?) rather than a breakdown
of anything down below. I will replace them all anyway but feel
sure they would have been safe for many more seasons.
So if you have nagging doubts over
the integrity of your fin-keeled First 24 (or similar) keel bolts,
take them out one by one while she's on the hard this winter (note:
they can actually be replaced in the water with one by one method).
They are easily removed and may not be as bad as you think. If
they are bad replace.
See more amusing comments below by Brian Pickton
Are those actually the HEADS of the keel bolts? Yes, those are
the heads of the keel bolts (see below left). Yes, they do get rusty.
The keel is cast iron and the bolts are steel so they are compatible
in terms of electrolysis. Surface rust on steel is more unsightoly
then weakening unless it is extremely advanced.. The relatively
mild steel bolts can withstand immersion in salt water where stainless
steel bolts, deprived of oxygen, will corrode quickly and are prone
to crevass crack corrosion. No, it has not been a problem so far.
Unlike some other boats, we have never heard of a keel falling off
of a Beneteau. The keel bolts, rust and all, will likely out last
you and me by many years.
As to tightening them with a
socket wrench, you can certainly give it a try when the boat is
on the hard, but don't expect much to happen.. On the hard a large
socket wrench with a 4 foot snipe on the handle and two of us heaving
for all we were worth would not budge our rusty keel bolts on The
Legend, and I would be surpirised if yours moved as well. If you
are concerned about their appearance clean them up with a wire brush
and paint them with rustoleum paint.
As to tightening them generally, if the boat is resting on her keel
on the hard and the bolts move up through the boat, then they definitely
need tightening and it may be time for an air socket and major surgery.
If however the bolts are (1) flush with the bottom (2) not leaking
water and (3) can't be turned with a large tool when the boat is
on the hard then ordinarily there is no cause for concern.
By the way , weeping keel bolts don't necessarily mean that the
bolts are loose. There is also the question of the fairness of the
keel to the bottom of the boat and the state of the caulking to
consider. I hope this helps and please do get back to us to let
us know how things turn out.
Brian Pickton of BeneteauOwners.net
Onboard The Legend,
Rodney Bay, St. Lucia
A bigger Beneteau Weighs In
Our 1986 First 405 had what I considered to be badly rusted keel
bolts. The 405 has a steel keel with the bolts inserted from inside
the hull and the hull to keel joint was separating by about a 1/4
inch at the front (a typical problem for this type of design). The
yard investigated by pulling out 4 of them and replacing them with
high tensile strength steel bolts (the originals were high tensile
steel bolts). None of the pulled bolts had any rust whatsoever on
the shank or threads of the bolts due to the heavy caulking in the
hull to keel joint. So although the bolt heads did not look pretty,
the bolts were not in fact too bad.
Total Cost $600 including labor.
None of the experts I talked to were very concerned about this problem
because it rarely leads to an actual failure. Note "rarely",
not never. The keel on my boat weighs 8000 pounds and under dynamic
loads it could require several times this force to keep it in place.
The typical keel is held on with 8 - 10 bolts and each one, if the
bolts are sized correctly should be able to take a loading of many
times the maximum loading on the entire keel. So there should be
quite a safety margin built into the design. It depends though on
how much of the head is remaining. You should wire brush all of
the rust off and inspect them closely. I would estimate that if
more than 25% of the material of the head is rusted away it may
be wise to replace it and the large washer under it. To prevent
further rusting from the inevitable water that will enter the bilge,
you should coat the heads with some form of sealant. Rust priming
paint doesn't last. I have used raw lanolin (available in drug stores)
recently but it remains sticky and picks up the dirt and in hot
weather it tends to run. The next thing I am going to try is to
paint them with clear epoxy. On the hull to keel joint we cleaned
out the gap as deeply as possible and sanded the rust away in the
gap. This is important because if you don't get rid of the rust
no sealant will work. We then filled the gap with 5200 sealant and
it did not open up the next sailing season. Hope this gives you
something to go on.