Case 2 Balsa Core

International Yacht Surveys was instructed by the owner and insurance company to carry out a structural survey on a 10.66 meter GRP balsa cored racing yacht. The yacht was inspected using thermography and ultrasound. The balsa core ran from the deck to hull join down to the water line. The keel frames were also constructed from a balsa core wrapped in GRP cloth and epoxy resin.The port side topside with rotten balsa core with two more small spots of rot aft of the main area of balsa rot. The rot was also confirmed using a moisture meter with readings taken outside and inside the hull.

The keel on the yacht had problems with the keel having excessive movement on the keel to hull join. The keel laminates were also inspected using ultrasound. The keel was dropped for inspection and it was confirmed that the keel laminates had delaminated . A work schedule was put in place.
1. Remove all internal keel frames and replace with correct core materials .
2. Cut out all delaminating keel hull laminates and replace.
3. Remove all rotten balsa core and replace.
4. Inspect work that has been carried out correctly at key stages of the refit. Final inspection to sign the yacht off.