Sharing some pics and description of what I did to my CB. First time it was removed. Ever. I shared bolt pics in another thread. Five of the six removed intact. One was so corroded that half of it is still in the keel and I could not remove it try as I might with extractor bits. Working upside down doesn't help!
Here were the issues:
1) Corroded bracket bolts
2) Lower padeye bolt not tapped straight into board
3) Stuck padeye bolts
4) Corroded bracket
5) 40 years worth of paint on the board
6) Cracked aft seam where two-piece mold was glued together
7) Lots of gelcoat cracks and nicks
Ground down tip from dragging on the bottom
9) Very thick and brittle trailing edge - not optimal
Pressed for time with other boat projects I gave the board to my buddy Barney who operates a boat building business from his basement building full cored racing Albacores (Hapco Marine). He's also an engineer. Here's basically how we solved the issues:
1) The one corroded bracket bolt could not be removed. I drilled an adjacent hole as far as I could into the keel. There must be stainless bedded up inside there because I could not easily drill more than 3/4". I filled the hole with high density filler and tapped. I figure that 5 of 6 new 5/16" bolts (316 stainless) plus one smaller 5/16" bolt will be good enough. Far less was holding the board in place previously. I may tackle the corroded bolt at a later date.
2) Barney drilled, filled, then re-drilled and tapped a new bolt hole into the board. This new hole is not solidly through the steel bedded in the board laminate. How the factory couldn't drill this straight is beyond me! Seems to be a problem for others.
3) Original padeye bolts were tough to remove. Had to apply heat and file a deeper slot into the screw head, then apply amply torque.
4) I had my shop welder clean and lay new beads on my bracket.
5) I sanded the old paint off which took hours. One nice surprise was the gelcoat was in excellent condition other than some chips on the surface from voids.
6) Barney ground, filled and glassed the aft seam
7) All gelcoat voids were picked, sanded, filled, and faired.
Barney used milled fiver and epoxy to fix the tip. Should be very resistant to wear now.
9) I wanted a better performing board and a tough trailing edge. Barney extended the trailing edge about 1" (yes, there is room in the trunk) with multiple layers of glass. The edge is now about 1/8" thick and very very strong. The extra area plus sharper trailing edge should provide better windward performance.
I also repaired the damaged front of the trunk at the bottom by grinding away the damaged glass (very thick in this area), adding a few layers of new tape, cutting the curve for the board leading edge, and fairing.
Barney applied a few coats of Interlux 2-part epoxy primer then three coats of Pettit Vivid bottom paint and burnished. He did an awesome job. Looking forward to getting this thing in the boat which is a whole other affair!