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New keel nut washers

The new laser cut keel nut washers are finally in place. After we reinforced the bottom/floor of the bilge with 4 layers of 600g biaxial fiberglass, we were able to install the new washers and tighten the nuts. The new washers are A4 (316/316L) stainless steel, 65x65x6mm with a 21mm hole and fit perfectly.


We tightened the nuts with a regular cheap 210Nm torque wrench we bought in the local hardware store only for this purpose. Theoretically M20 A2-A4 fasteners in their new condition should be able to clear 273Nm when dry or 246 when lubricated, but we didn't want to get too close to the maximum new factory values and risk damaging the threads or breaking the rods and also we used a small amount of Loctite on the threads to prevent them from loosening due to vibration or movement, so we tightened them to 210Nm.
Tightening them even to 210Nm was not an easy task due to the poor access. I had to use my whole weight and if it was possible push the wrench with legs with my back supported. We had two extra nuts which we put on the first and last bolt as an extra 'locking nut', also just to keep them as spares and not loose them, they might be useful if for some reason in the future the threaded rods would need to be extracted from the keel.

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