Repairing a delaminated rudder

(Please note I filmed some segments vertically and some horizontally by mistake, but the subject and images are still good for intended purpose.. I'll do better next time!!)
This is a video I created when I fixed a delaminated rudder on a sailboat. Below is the list of tools and products I used. The sailboat is a Mirage 26 that had been left on her cradle over 3 years without the rudder drain plugs removed. Hence the Canadian winter freezing cycles caused a delamination of the original balsa core material. A delaminated rudder can collapse and easily break away under some sailing conditions where the rudder would be under load or stress.
Tools used:
Drill
Drill bit for 1’’ hole
Long shaft ¼’’ drill bit to reach in and grind out core
Flexible cutter blade or hand saw
Palm sander
Shop Vac
Disposable gloves
Lint free rags or paper towels
Tapping kit
Products used:
Sandpaper (80, 220 and 150 grit)
Acetone
50/50 alcohol mixture
One can of low expansion insulation foam
Interlux Watertire Epoxy Filler
Interlux Interprotect 2000
VC17 antifouling paint (or any antifouling of your choice)