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Bongo Bob
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9 Posts
Discussion Starter · #1 ·
I am in the process of replacing my engine in my Alberg 30. Because of slight differences in the footprint of the new engine vs. the old one, I have to remove the old flexible coupling the is on the prop shaft and replace it with a new one. This will require getting the new coupler fitted and faced. If anyone has tried this, you know how tight they are on the shaft. Anyway, what I would like to do, once I get the coupler off, is to remove the shaft from the boat while it is in the water. Has anyone tried this before? I visualize getting a cap that I can screw on over the log side of the packing gland and sliding the shaft out thru the cutlass bearing. In the event that I can't get the coupling off, I would try to take the prop off and then remove the shaft thru the inside of the boat (remember, the engine is NOT installed at this time). In either case I would need a cap the same size as the log side of the packing gland. For a 7/8 inch shaft, does anyone know what size that would be? Any advice or ideas are more than welcome...

Bob
 

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Senior Member
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19,488 Posts
This is a pretty risky thing to be trying.. A hell of a lot of water is going to want to come into the boat during the removal.. this is not going to be as quick as a transducer/plug swap....

I think you're asking for trouble.. but if I was to try this I'd simply get a spare piece of 7/8" shafting and slide it into the gland as the prop shaft is pulled through.

But again, this is really a haul-out job..
 

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Bongo Bob
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9 Posts
Discussion Starter · #3 ·
Yeah, I can see where your coming from... but my idea is to pull the shaft from the prop end and before it is all the way out, replace the packing side of the gland with a cap. If I have to pull the shaft into the boat, then would stuff a rag or something in the log at the back end before the shaft is completely removed and then after it is all the way out put the cap on. Only problem is finding a cap that will thread on to the log end of the packing gland.
 

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Señor Member
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1,457 Posts
I'm getting the willies just thinking about this -- talk about getting waaaay out on the limb!

If you do take a stab at this, do it in shallow water and by all means have someone filming it... Strike that last bit -- your insurance company may subpeona the film to negate your claim :D

Seriously though, why take the chance? It sounds like you're planning on being shaftless for a fair amount of time, and the gremlins are going to be working overtime trying to figure out how to defeat your best laid plans.

You could just bang a wooden plug into the hole (consider it a dress rehearsal for a mid-ocean damage control evolution), and then drive it back out with the newly finished shaft. That'd be a little faster than fussing around trying to get a threaded cap onto that gushing geyser.

Anything you could do to raise the stern (and thus lessen the ambient water pressure) would probably be a good idea as well. The closer you can get it to the surface, the lesser the pressure will be.

Do think long and hard before you actually pull the shaft out. Consider everything that could potentially go wrong and take countermeasures to mitigate the risk.

Hope it all comes out (and goes back in) well.
 

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Senior Member
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Yeah, I can see where your coming from... but my idea is to pull the shaft from the prop end and before it is all the way out, replace the packing side of the gland with a cap. If I have to pull the shaft into the boat, then would stuff a rag or something in the log at the back end before the shaft is completely removed and then after it is all the way out put the cap on. Only problem is finding a cap that will thread on to the log end of the packing gland.
It will be a problem finding a match.. (btw - have you noticed that so far it's 2-1 against doing this in the water???) Pipe caps are tapered thread, the packing gland is not. If you're absolutely bent on doing this, maybe have a rubber disc cut to fit inside of your existing packing gland nut, and slip it into the nut and reinstall it (assuming that you have the time.) at least then you'll know the thread's a match. Suck it down tight and the leak should be minimal..

It's still a bad idea ;) :eek:
 

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Bongo Bob
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9 Posts
Discussion Starter · #6 ·
Yep, yep.... now it's 3 to 1:D Looking more and more like I'm gonna hafta have her hauled...:mad:
 

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Senior Member
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.. actually that'd be 3-0... good call!
 

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OK, just to be contrarian (and to see what sort of abuse I get from those wanting you to spend money on an unneeded haulout): First: Get a short piece of the same size shaft from the prop shop that's going to be facing the flange to the shaft (are you sure you need that? What sort of flexible coupling are you going to use between the shaft and the tranny?); if it's not a prop shop but a regular machine shop then stop by the local prop shop and get a short length of the same sized shaft. They have lots of bent shafts lying around and you only need a short length so exactly straight isn't important--- proper diameter is. Round the edges of the outboard end (the end that's going to going into the hole once you pull the shaft into the boat) so it doesn't cut the packing when you slide it in. Jump into the water and remove the prop and make sure the shaft is free of zincs etc. and fairly clean (no marine growth). Pull shaft from inside the boat and replace with the stub shaft. You probably won't need to tighten the gland but if it drips too much then do so. Tie a restraining line or cord around the gland and over the end of the shaft stub to hold it in the hole. I doubt you will get much water into the bilge. I've replaced gate valves (OH shutter, the horror of it... gate valves on a boat) in the water and this is easier; so be prepared, keep your cool and all will go well.

You are going to need the boat in the water with the shaft in the hole to properly align the shaft and the engine/transmission, so reverse this process when ready to install the engine prior to setting the engine onto the mounts.

Bests,
Wiley
 

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Bongo Bob
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9 Posts
Discussion Starter · #9 ·
Hmmmm.... now it''s 3 to 2...:rolleyes: I will be using a R&D flex coupling between the shaft coupler and the tranny. I had originally intended to use the existing flex coupling (older rubber and metal coupler) with the new flex coupling but it pushed the shaft back too far and interfered with the rudder. Could not use the existing flex coupler as it was not thru bolted and I would have had to pull the tranny flange off to capture the bolts that would go into the old coupler. Putting the R&D flex coupler between them would have fixed THAT problem. Didn't want to mess with the brand new motor/tranny, though.
 

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I certainly wouldn't

I wouldn't attempt this, but I think it can be done. If you have to pull the shaft from the inside, I would get me a couple of wax toilet bowl rings, and stuff them in the shaft log, as you pull the shaft. This will not make it leak proof, but will certainly slow it down a bunch, till you get something more solid on the inside. Then you slide the new shaft back in, the shaft will push the wax out, no problem. One thing for sure, keep us posted on how you go about it, and how it works out.
 

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Bob, as a general rule of thumb it is not considered to be a good practice to use multiple flex couplers one after another; so the pushing the shaft back such that it interferred with the rudder by the second flex coupler was a boon in disguise.

As you have the engine and tranny out and have more easy access to the recalciltrant flange, have you tried a product called Kroil? I'm not affiliated with it save as a user and was put on to it by a friend who worked on subs in Bremerton WA. It is pretty amazing stuff for loosening that which seems permanent.

Bests,
Wiley
 

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snake charmer, cat herder
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2,650 Posts
god made toilet seal wax rings for a reason--most of them not toilet related LOL---th esoft wax will mold into a mess and be able to be pushed into the outside and inside of the shaft log for a time---my formosa has this for a minuet so i can sail in other peoples boats as i save for the haulout---is working nicely---the boat has only had 20 seconds of pump time in over 6 weeks...LOL...and i am sailing other boats for a it yet.....goood luck. the best thing if you insist on doing this job in water is to careen her against a shoal....isnt that hard to do ---goood luck and film this--we want pix!!!!!!!

(flatracker has it right!! didnt know there were other crazies using wax rings for our flotational requirements...LOL!!!!)
 

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S/V Cristall Moonlight
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6 Posts
Okay, I admit it...

I actually replaced a thru-hull in the slip.

Pretty simple actually. Several different sizes of rubber stoppers available. Wife inside the boat. Me with the scuba gear and a bag of stoppers. Shop vac to clean up the water.

Pulled the thru-hull, and slammed in a stopper from underneath the boat. Matched up the new hardware with all the right pookey, pulled stopper, and slammed new thru-hul into place. Smaller stopper slammed into new thru-hull while we threaded everything together and got it all watertight.

Made wife VERY nervous. (on second thought, having a nervous wife may be more costly than a haulout):D

If you know you can do it, go ahead. If not, you probably should opt for the haul out...

YMMV,

Don W.
 

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Bongo Bob
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9 Posts
Discussion Starter · #14 ·
Thanks for all of your inputs. Definitely helped me make up my mind. In the end I've decided to have the boat hauled and do it on the hard.

Cheers,
 

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Don Radcliffe
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398 Posts
That's no fun for us! If you can't find a piece of 7/8 shaft or a 7/8 bolt, just pound a tapered wood plug in the packing gland as you slide the shaft out, then secure with duct tape.
 

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I think this job is one that is scarier to think about than it is to do. If you have a helper, your boat is not going to sink. If you get the plug wrong you will probably have to stop the water with your hand, which is where the helper comes in! I wouldn't pull the shaft into the boat. The inboard end can be cleaned up so it won't bugger the shaft seal on the way out. Pulling it into the boat will mean pulling in a section you can't see or clean, and that is likely to be a real problem. I'd make a plug with a long shallow taper 6" long. Make it about 3/4" diameter at the small end, 1" at the large and Leave 6" of the 1" for a handle. Use it push the shaft right out until it jams tight in the packing nut. Then use a tie wire through a hole in the handle portion and around the packing nut to ensure it can't back out.

I estimate that the maximum flow out of a 7/8" hole in water that shallow is maybe 30 gallons per minute. So the amount you might get in during this time is at worse a few buckets to bail.

Further inspiration:
I work with waste water. A collegue accidently removed a 2" pipe plug in the top of a 12" pipe, connected to the bottom of a tank filled 12 feet deep with 30,000 gallons of raw sewage! He was on the fourth floor of a luxury high rise apartment building in NY city, and he managed to put that plug back in! That pipe actually COULD shoot a geyser 10 feet high!

Good luck with your project. I'd do it!

Gary H. Lucas
 

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I'm not 100% sure, but I think on an Alberg 30, the shaft will not clear the rudder when pushing it out. At least not with the prop on.
Brian
 

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Bongo Bob
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9 Posts
Discussion Starter · #18 ·
Shaft Replaced

Turns out that after hauling the boat and removing the shaft, that the shaft, packing gland and cutlass bearing ALL needed to be replaced! The shaft was scored forward of the cutlass bearing and the packing gland was for a 3/4" shaft instead of the 7/8" shaft, so was impossible to get off and would only move where it had worn down the shaft. Cutlass bearing was delaminated from the metal sleeve and somewhat worn.

Now its just a problem of getting the new engine mounted and aligned correctly. Had to put in new mount stringers and on an Alberg 30 there is only about an inch or two of play on where the shaft can be.... fun 'n games on boats, eh? :eek:
 

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snake charmer, cat herder
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2,650 Posts
replacing a thru hull in water is a waaay lot different than replacing the shaft , gland and log and cutlass bearing in the water----for the thru hull, all needed is a toilet plunger and a friend to hold it for a bit of time--the other needs to have the waters part for a day or two--is difficult to get that done--was done last about how many thousand yrs ago, and only the red sea LOL.....haul out is generally the only way to go unless careening is a possibility--thenye best have act together and all parts in one place and a few toilet wax rings for in case of water rising before work is finished. and the blessing of the gods lol....glad you hauled out and goood work on the repair.....
 

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Sorry, I'm laughing too much! I had a serious issue this summer (a long story), that required replacement of the prop shaft and cutlass bearing. Everyone in my harbour recommended haulout. Wussies, and I'm cheap! On advice of one member, I motored to a shallow slip so that the keel was just on the bottom (turned out to be unnecessary). We then secured her to the slip so that if she took on water, the extra lines would hold her up and against the dock (also unnecessary). I came up with a plan to plug the hole when the shaft was removed, and 3 backup plans (unnecessary but one). My first choice was an expanding plug as used on small craft to plug the drain hole. Unfortunately, it was too small and I only purchased the one size. Plan B was a regular bung of which I had an assortment on board. This is what was used to success. A third option, as I couldn't get a spare piece of shaft, was a wood dowel the same size. This was just as well, since the bung swelled a bit, which would have made it impossible to remove the dowel without taking it out in little pieces. To the bung, I manufactured a wire net, similar to that on a champagne bottle to hold the cork in. I secured the wire to the stuffing box after the bung was in. At the back end (outside the hull) I stuffed a bag of plumbers putty (still in the bag). The idea here was for it to reduce the water pressure on the bung. This all worked well, and only about a cup of water came in as the bung was put on and as the shaft exited outward. Stayed like this for over a week, without a drip. When it came time to put it back together, I removed the bag of plumbers putty first, then the wire. Amazingly, the bung had swelled and would not come off without the use of grips and a bit of force.
 
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