best way to refasten/stregthen a fin keel w/sboat still in water?

Question

thru hull bolts are rusted, can feel the keel cavitate under a strong to extreme sail. Thought about butting up new u-channel steel and laging new lag screws into keel to see if it sucks it up tight. s/vessel is a 30' tall mast Columbia, Perry design sloop.

Answer 1

There is NO WAY you can do an adequate repair in the water...and you are in immanent danger of having the whole deal come off if you can feel cavitation. I'm surprised you don't mention leaking around the bolts as well.

I just finished doing keel boat replacements on a Columbia 50 and it was a bear.........bolts rusted off inside, rusted solid outside.......torches, wrenches, drill bits, sweat blood and tears...ballast keel had flange at the top that the bolts passed through...we needed to take the keel off after we got the old bolts out and re-bed it before putting new bolts in.....but you have to do it cause you may lose the whole boat in heartbeat..

The u-channel inside idea is almost right...you'd have to drill down into the ballast keel, tap the hole, and then try drawing several thousand pounds up tight with machine screws ( lags are too coarse threaded to work)....this would be a lot easier with the boat out of the water and sitting on the keel and the ocean not pouring in.

While you're at it with Columbia, check the mast step and see whats holding it...and the mast and the whole rig....in place. Be prepared to be shocked and amazed.......