Here is a response I got via text from Christian Pschorr on the matter of keel bolt torque:
Regarding the keel, it’s recommended that keelbolts be re-torqued every 5 to 7 years. Almost no one does this, of course. Guidelines:
• The boat has to have it’s weight on the keel on the hard
• The keel should be supported by only 2 bits of timber to discourage uneven loading
• The nuts must first be unscrewed slightly before setting the torque
• Consider backing off the nuts entirely, and applying TefGel or sealant under the backing plates and around the fiberglass where the bolts penetrate to insure there are no leaks. (While leaks are unlikely, this would make sure, and it’s easiest to simply add this to the work list.)
• Tighten each nut to 123 kgf*m
As long as the keelbolts don’t show evidence of serious galvanic corrosion, it is unlikely that they are compromised in any notable way. Such galvanic damage would be evident in other gear on board as well, like the prop, shaft and engine. One of those 16x 40 mm bolts had a breaking strength of over 150,000 lbs new, so the designed safety factor is considerable. The number and size of the keelbolts were designed to last the life of the boat.
Cheers,
Florencia
SV Free Range
54 RS #52
