Keel Bolts

[shemandr]

Take Dianaofburlington's advice to heart.
If you have a sailboat specific problem do not have a yard not experienced in sailboat problems fix it. I had a problem and the yard where I wintered the boat wanted the job. But it was obvious they weren't up to it. They told me the boat might sink if I didn't do the repair there. I told them "No." When they launched my boat in the spring I moved it to a yard that considered a job like that a regular day. The boat didn't sink. It went smoothly. They had the keel off before I got home from the delivery.
I feel for the OP. He followed the "Rules" and got screwed. Too bad. I'm not expecting the legal remedy to work. Asses are well covered. A bad story.

 

[Jan_H]

The keel-bolts are usually torqued well beyond what is necessary to support the weight of the keel when the boat is upright. This preloads the bolts to prevent the keel joint from opening up due to the large moment that develops at the keel-hull interface when the boat heels. The seven 1” diameter keel bolts on a h380 each only need to be torqued to ~16 lb.ft to support the 5900 lb keel, so when torqued to 100 lb.ft, over 80% of this torque is preloading the bolts.

The tensile strength of 5200 is 700 psi, compared to 80,000 psi for a 304 SS bolt. If the area of the hull-keel joint over which the 5200 exerts its bond is more than 100 times the cross section area of the keel bolts, the 5200 alone would indeed be at least as ‘strong’ as the keel bolts. However, this also requires that the bond strength between the 5200 and the material to which it adheres (fiberglass hull, lead keel) is at least as strong as the 5200 itself. Keel bolts do not have this issue, although crushing the fiberglass hull or shearing a bolt by over-torqueing are potential issues.

Properly done, the 5200 and keel-bolt attributes create a complimentary keel attachment system.

Jan