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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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Bilge reinforcement - Part 2

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After careful surface preparation the bilge reinforcement project continued with laying the new laminate. I consulted with West System on what fabric to use and they suggested biaxial cloth without chopped strand matting. The biaxial cloth is very strong and CSM would just add weight. We bought 600g biaxial cloth with 45/45 degree strands from Composite24 and West System 105 epoxy with 206 fast hardener at a local marine store.
Cutting fabric
The work was done in sections, we started with the bilge bottom/floor while the keel nuts and washers were removed. It got 4 layers that come up 10cm at the bilge sides. This area gets most of the loads and we wanted to reinforce it by connecting the fabric on the bottom to the one to be layed on the sides.

In theory these types of reinforcements are suggested to be done either with the keel dropped or while the keel is hanging so it's not compressing the joint while the boat is standing on the keel. The idea is to avoid building …

Bilge reinforcement - Part 1

Ann-Riis had delamination at the floor beam to hull attachments probably due to earlier groundings and we could also see the swinging/pendulum keel symptom when the boat was transported with the keel hanging. It was time to do something about it. The plan is to reinforce the whole keel-to-hull joint with 3-4 layers of 600g biaxial fiberglass cloth, re-bond the floor beams to the hull with at least 6 layers and add new structural members to stiffen up the construction against side loads.

Delamination:


In the fall of 2019 we started the keel/bilge reinforcement project. It took several weekends to sand everything and it was probably the most difficult boat work (or any type of work really 😃) I ever did. I covered the working area with plastic protective foil, but it didn't do much. The fiberglass dust was so intense that after a while the tape holding the foil was falling off and the dust covered every corner of the boat. I killed one orbital sander and one vacuum cleaner during …

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