Keel Bolts. To pull or not to pull, that is the question?

noswellplease

noswellplease

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I have a Trintella 11, which is a 31 foot long keel boat with encapsulated keel. Now the boat is old 37 years but well maintained throughout that time. Now my yachting friend who is quite knowledgeable though he has no boat himself tells me that I should pull a bolt or two....(far from easy and inspect them) My local yard says they are encapsulated so they are ok and to leave well alone. I wonder has anyone ever pulled the bolts on a Trintella 1 or 2 or on similar type craft. I don't want to make work for myself if I can avoid it afterall I have plenty of other maintenance jobs to do as it is....Russ
 
Hi Russ - I have a Seal 28, also with a long keel. My keel is held on with monster s/s studs and is not encapsulated. It doesn't seem to attract any comment from the surveyor, though. From my wooden boat days, I seem to remember that keel bolt corrosion mostly happened in the wood, not the iron. Perhaps moving to GRP construction has eliminated this particular boat owner's nightmare.

Cheers! Neil
 
IMHO I would leave well alone. For corrosion to take place you need both moisture and oxygen. If my memory serves me right the entire ballast 'lump' is encapsulated as well as the bolt heads in the bilge. Unless there has been damage to the G.R.P covering the iron allowing water ingress there should be no problem. by exposing the bolts to inspect them you are making water ingress more likely in the future. Also if there were corrosion present Iron oxide takes up a much greater volume than un-rusted steel, I think that bad rusting beneath the G.R.P would probably cause the laminate to lift and even split letting rusty water out. If in your position I would not be worried at all. Regards, Mike.
 
Leave well alone

unless you have obvious signs of oxidisation (lifting GRP).

Wevers' ran a good yard, it's unlikely (unless a high-speed grounding) that the keel will have moved.

As an aside to Trouville's comment, mild-steel below the waterline is a no-brainer, speaking as one who's had to clear up the mess.
Many, making a virtue of necessity, maintain that only galvanised mild steel should be used for attaching an external keel to a wooden boat - though the pros and cons are close-argued, I'd avoid the issue.
Whichever is used, keel-bolts on a wooden boat should be regularly inspected unless the boat is built to Lloyds with bronze fixings, which is probably where your advisor was coming from.

Stainless steel crevice corrosion only occurs in anaerobic conditions when the crevice is <1mm wide. Though a real problem with 303 or 304, (failure within 12 months can occur) it's not too bad with 316.
 
[ QUOTE ]
You should NEVER use stainless steel for keel bolts!They will break due to crevis corrosion

[/ QUOTE ]

Funny.... most Westerlies had stainless keelbolts as standard. The 1968 Nomad I sailed 20 years ago had them - good as new in 1988 when I sold her. AFAIK, many other builders used them as well on GRP boats. Corrosion can onl occurs if they get wet. Also most prop shafts nowadays are stainless.

If keel bolts are encapsulated in the GRP, and there is no sign of leakage or movement, I would leave well alone.
 
Re: Keel Bolts. To pull or not to pull, that is the question?

Quite agree. Lack of keelbolts is, ahem one of the reasons for encapsulating a keel...
 
Re: Keel Bolts. To pull or not to pull, that is the question?

But some manufacturers had bolt on keels, then encapsulated the keel bolts to preserve them.....

Moulded keels with the ballast inside the moulding dont have keel bolts.
 
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