shaft log replacement

I have a forty ft. Sam Crocker ketch built in 1965 cold molded with 4 layers of Ceder. The shaft log leaked and the water settled in the dead wood causing the wood to explode into toothpicks as well as the fiberglass that was added 7 years ago. I discovered the cause was a lead shaft log very closely fitted that has failed from electrolysis. I have pulled and twisted to remove with no result I may have to bore the old lead out. Many years ago I had to do some thing similar and I used two pipes with one fitting in the old hole and the second outside that I sharpened to create teeth I had to turn the cutting pipe by hand ans the process was painfully slow. I can conceive of a drill bit with a center to guide the cutter but I do not know where I would find such a tool. I am open to any suggestions. Thanks Guy

 

If the wood is deteriorated and you need to cut a bigger hole anyway, use a hole saw of larger diameter. Cut to the maximum depth and chip the material away. Keep on until it is all out.

 

Hi thanks for the reply. I have cut the deadwood away to where the hull starts and the wood the rest of the way appears solid. The concept of cutting a larger hole using the old lead shaft log as a guide sounds good. I have no conceivable way to get in the hole to clean it out past the first few inches The log is buried in about four feet of solid wood and could only be reached by dismantling the Keel and Keelson. I am not sure exactly how you were suggesting the lead I am cutting around is removed. One suggestion was to push a shaft through with a cutter and pulling it out slicing the lead and collapsing the shaft log. Thanks Guy

 

Once you cut around it with the hole saw, a chisel will chip the pieces away.

 

shaft log removal.

Hi Gonzo,
I seem to be missing something. I would need a chisel with a five foot blade and some way to pull the pieces out. The shaft hole is 2 inches in diameter and 5 ft long in the keel and keelson with the only access without removing engine being from the stern. There is an additional 18 inches exposed now after the dead wood has been removed. I can't conceive how your technique could be possible Can you clarify please Thanks Guy

 

You don't need a cabinetry grade chisel. A sharpened rebar will be adequate to chip the pieces away.

 

Ive never heard of a lead shaft log, I always used thick walled copper threaded into the stuffing box. Anyway, the way we open the hole out is to make up a boring bar and this may work for your task, buy a length of steel shafting the same size as the prop shaft, have a machine shop turn one end down to fit the chuck of the largest, slowest drill you can find, drill a hole thru it with an opposing tapped hole for a set screw and make up a cutter out of hardened drill rod to lock in the hole with the set screw. You will need to be able to move the shaft in or out so you need to make up some bearings out of hardwood inside and out. When building new we fasten these to the engine bed and usually the cutless bearing on the strut on the outside (modern hulls) but you have the engine in the way so you will have to get creative. If you indeed have lead in there it may work if you make multiple passes with very small cuts, lead is a ***** because it does not clear out of the hole easily.

Steve.

 

Lead pipes used to be fairly common in some areas. The problem is that lead is soft so it will wrap around a boring bar.

 

Interesting, I have never heard of lead used for this in 40 years of boatbuilding, i like learning new things. I agree a boring bar may not work which is why i said lead is a *****, it could possibly work though as long as you keep adjusting the bite so you are only taking small scrapes and keep pulling it out to clear the hole.

Steve.

 

The hole would be slanting down so you could probably tape a 5' length of 1/2 pvc pipe onto an air hose and blow the pieces out, or onto a shop vac and suck them out. Not that it would suck the larger pieces up the pipe, but they would stick on the end and you could pull them out 1 at a time.

 

Thank you all for your help. I managed to remove the lead shaft log by crushing the lead pipe with multiple insertions of a sharpened rod, Then I tied a rope to the rod and used a pry bar to pull very hard until it let go. I thank you again for taking the time to give your advice. Guy