extending the shaft log

[Andrew Blight]

There have been a number of mentions on the board from those who have extended their shaft log inward on the CD30 in order to be able to maintain the stuffing box or replace it with an accessible dripless system. Now that I fully understand just how bad the original design was and how dangerous it is to have a rubber tube connected to the ocean that cannot even be inspected without lifting out the engine, I would love to do the shaft log extension trick. I would therefore like to know if anyone has done this themselves, and how, or if it was done by a yard, how much did it cost, and any lessons learned.

As an aside, I just removed my shaft bearing and saw not sign of set screws anywhere. Anyone with a similar impression that the bearing was just press fit without retaining screws on their CD?



ablight@acorda.com

[chuck yahrling]

There have been a number of mentions on the board from those who have extended their shaft log inward on the CD30 in order to be able to maintain the stuffing box or replace it with an accessible dripless system. Now that I fully understand just how bad the original design was and how dangerous it is to have a rubber tube connected to the ocean that cannot even be inspected without lifting out the engine, I would love to do the shaft log extension trick. I would therefore like to know if anyone has done this themselves, and how, or if it was done by a yard, how much did it cost, and any lessons learned.

Andrew;

I recently removed the cutless on my CD-27, during which I discovered that only one of the original setscrews was left. These setscrews were on the extension of the shaft tube into the aperature. The aperature was mangled, so I cut it off and am re-glassing a new "extension" of about 1 inch, just to hide the brass.

The new cutless freely spins in the tube, so setscrews are necessary on my boat. So, I drilled through the back of the keel about 2 inches forward of the aperature and epoxied-in some stainless nuts and setscrews, which will be buried with more epoxy and marked with locating grooves.

I solved the accessibilty problem by installing an access hatch in the cockpit sole when I redid it this Spring. It's really not that hard a job and is an immense convenience for getting at the rear of the engine. It also allowed me to relocate my battery tray lower and more forward, freeing the starboard locker.

As an aside, I just removed my shaft bearing and saw not sign of set screws anywhere. Anyone with a similar impression that the bearing was just press fit without retaining screws on their CD?

yahrling@cybertours.com

[John]

There have been a number of mentions on the board from those who have extended their shaft log inward on the CD30 in order to be able to maintain the stuffing box or replace it with an accessible dripless system. Now that I fully understand just how bad the original design was and how dangerous it is to have a rubber tube connected to the ocean that cannot even be inspected without lifting out the engine, I would love to do the shaft log extension trick. I would therefore like to know if anyone has done this themselves, and how, or if it was done by a yard, how much did it cost, and any lessons learned.

As an aside, I just removed my shaft bearing and saw not sign of set screws anywhere. Anyone with a similar impression that the bearing was just press fit without retaining screws on their CD?

I've done the shaft log deal on our '83 30. It was a difficult, time consuming, awkward, tedious job. A lot of cursing was going on to say the least. We were not praising Alberg nor CD those couple days. The worst part of the job was glassing the extension log to the pre-existing log. It was incredibly difficult to reach in order to prep the surface of the existing log and then to keep the extension positioned properly while glassing it in place. I might add that we have a access hatch in the cockpit sole that I had built prior to the shaft log project. There is a large custom battery box below the hatch that can be converted to a seat to work on the engine when the batteries removed. Without the hatch I don't think we could have succeded in extending the log without lifting the engine up from the beds quite far. In any event we did get the extension glassed. (*#@!^!) However, that alone is not enough. (double *#@!^!) The extension log because of its added length requires support from the underside to prevent movement. I made a small 3/4" thick marine ply bulkhead that had a half circle notch cut into the center of the top edge. I scribed the bulkhead to fit the after area of the bilge about 8" forward of the aft end of the bilge. The bulkhead was made tall enough to reach from the bottom of that shallow area of the bilge up to the underside of the shaft log extension, the log rests perfectly into the notched half circle (seat) as previously described. The bilge area was prepped for glassing, and the bulkhead completely glassed into place. The new shaft log was glassed into the notch to prevent any possibility of movement. When this is all done it can be seen that the glassed joint of where the extension butts to the old log is lower than the top of the new mini bulkhead. The area (void) between the aft end of the bilge and the mini bulkhead was then filled with epoxy thickened with cabosil, unstranded glass cloth was also mixed in. This was done slowly, a little at a time using a slow hardener. West System was used, 205 with 207 hardener. Care not to create excess heat using to much epoxy at one time is very important or you could damage your hull lay-up. After many pours of the epoxy mix eventually the void area is filled which completely encapsulates the glassed joint of the two shaft logs. The entire face of the small bulhead was coated with epoxy as well and glassed over. Next a new dripless shaft seal was installed. The shaft log extension now locates the shaft seal about two inches aft of the coupler under the Volvo transmission. Keep the original stuffing box with a new piece of hose and clamps as a spare. Now the seal is a piece of cake to inspect or work on. You won't find a boat easier. If you are going to do this job do yourself a big favor and fabricate or install a hatch in the sole of the cockpit first. I made ours out of teak to resemble a teak deck, caulk lines and all. It looks real nice and is extremely fuctional. It does rise about 1 1/2" higher than the rest of the sole but you could add a teak grate to the rest of the sole to maintain the same level. I didn't make a grate as it doesn't make for any problems the way it is. It is held in place with flush bronze hex bolts that screw into bronze plates below the sole. I'm changing my e-mail so if you want more info make a post here and I'll get back to you.

[D. Stump, Hanalei]

Andrew,
Hanalei is a CD-30, 1984, hull 364. She has the Universal 18, 14HP diesel instead of the Volvo, so she does not have the "V" drive that required the extension you describe. But, here is something you might want to consider. The original shaft log was fiberglas on Hanalei and extended a short way into the bilge, the shaft seal was attached to the extension.. For whatever reason, engine/shaft misalignment most likely, the previous owner experienced water in the bilge each time he went to the boat. He installed an automatic bilge pump. Didn't work! On inspection they found that the fiberglas extension had cracked, opening a direct path from the sea to the bilge! To fix it, Gordon Swift (a real salty dog, that taught at Wooden Boat School a couple times and has built his own wooden 36' ketch) from Seabrook, NH, cut off the internal extension, cut off the external extension(that covered the set screws for the cutlass bearing) and installed a new red brass stuffing box, fiberglassed in place. The stuffing box is threaded on the external end and threads into a proper stuffing box retainer that is bolted to the aft end of the keel where the shaft comes out. Inside, the shaft seal attaches directly to the red brass shaft log. To do this, I think all you would have to do is pull the shaft, cut out the old FG log, install the new one (and it can be short, make it of convient length so you can get to the shaft seal) and you are done! The log does not need to go all the way to the transmission. In fact, the end should be below the water line particularly if you use a drip seal. If it were above, no water to the seal! Gordon did an excellent job, and I no longer worry about her sinking at the dock! Also, this would not require cutting a hatch into the cockpit sole and all the hassel that would entail. I was recently looking at a '79 CD-30 with the old log, and was amazed that Carl would design it that way. I didn't see inside, but the outside looked shall we say, "not too nautical"!

Hope this helps...
Dave Stump
Captain Commanding
s/v Hanalei (CD-30)

[John]

There have been a number of mentions on the board from those who have extended their shaft log inward on the CD30 in order to be able to maintain the stuffing box or replace it with an accessible dripless system. Now that I fully understand just how bad the original design was and how dangerous it is to have a rubber tube connected to the ocean that cannot even be inspected without lifting out the engine, I would love to do the shaft log extension trick. I would therefore like to know if anyone has done this themselves, and how, or if it was done by a yard, how much did it cost, and any lessons learned.

As an aside, I just removed my shaft bearing and saw not sign of set screws anywhere. Anyone with a similar impression that the bearing was just press fit without retaining screws on their CD?

I've done the shaft log deal on our '83 30. It was a difficult, time consuming, awkward, tedious job. A lot of cursing was going on to say the least. We were not praising Alberg nor CD those couple days. The worst part of the job was glassing the extension log to the pre-existing log. It was incredibly difficult to reach in order to prep the surface of the existing log and then to keep the extension positioned properly while glassing it in place. I might add that we have a access hatch in the cockpit sole that I had built prior to the shaft log project. There is a large custom battery box below the hatch that can be converted to a seat to work on the engine when the batteries removed. Without the hatch I don't think we could have succeded in extending the log without lifting the engine up from the beds quite far. In any event we did get the extension glassed. (*#@!^!) However, that alone is not enough. (double *#@!^!) The extension log because of its added length requires support from the underside to prevent movement. I made a small 3/4" thick marine ply bulkhead that had a half circle notch cut into the center of the top edge. I scribed the bulkhead to fit the after area of the bilge about 8" forward of the aft end of the bilge. The bulkhead was made tall enough to reach from the bottom of that shallow area of the bilge up to the underside of the shaft log extension, the log rests perfectly into the notched half circle (seat) as previously described. The bilge area was prepped for glassing, and the bulkhead completely glassed into place. The new shaft log was glassed into the notch to prevent any possibility of movement. When this is all done it can be seen that the glassed joint of where the extension butts to the old log is lower than the top of the new mini bulkhead. The area (void) between the aft end of the bilge and the mini bulkhead was then filled with epoxy thickened with cabosil, unstranded glass cloth was also mixed in. This was done slowly, a little at a time using a slow hardener. West System was used, 205 with 207 hardener. Care not to create excess heat using to much epoxy at one time is very important or you could damage your hull lay-up. After many pours of the epoxy mix eventually the void area is filled which completely encapsulates the glassed joint of the two shaft logs. The entire face of the small bulhead was coated with epoxy as well and glassed over. Next a new dripless shaft seal was installed. The shaft log extension now locates the shaft seal about two inches aft of the coupler under the Volvo transmission. Keep the original stuffing box with a new piece of hose and clamps as a spare. Now the seal is a piece of cake to inspect or work on. You won't find a boat easier. If you are going to do this job do yourself a big favor and fabricate or install a hatch in the sole of the cockpit first. I made ours out of teak to resemble a teak deck, caulk lines and all. It looks real nice and is extremely fuctional. It does rise about 1 1/2" higher than the rest of the sole but you could add a teak grate to the rest of the sole to maintain the same level. I didn't make a grate as it doesn't make for any problems the way it is. It is held in place with flush bronze hex bolts that screw into bronze plates below the sole. I'm changing my e-mail so if you want more info make a post here and I'll get back to you.

Correction, that previous post should read as follows:
105 resin and 206 slow hardener
Had a bad hair day, sorry.