Pitted shaft in the stuffing box. What to do?
Moderator: Jim Walsh
Pitted shaft in the stuffing box. What to do?
While the boat was out, I decided to pull out and replace the packing. I found that the shaft was pitted pretty bad on both sides. My zinc had worn off and was missing for probably a couple months, at least.
The yard says I need to replace the shaft or the pitting will just keep tearing apart my stuffing. I have a CD28, I don't know if there is any room for a PSS or if it would be any less expensive than replacing the shaft.
I was wondering if anyone had a brilliant idea with any new, wizz-bang technology that would allow me to keep the pitted shaft in place (assuming it is less expensive than replacing it).
Or, anyone have a shaft to sell?
RPerlot
CD28 #352
The yard says I need to replace the shaft or the pitting will just keep tearing apart my stuffing. I have a CD28, I don't know if there is any room for a PSS or if it would be any less expensive than replacing the shaft.
I was wondering if anyone had a brilliant idea with any new, wizz-bang technology that would allow me to keep the pitted shaft in place (assuming it is less expensive than replacing it).
Or, anyone have a shaft to sell?
RPerlot
CD28 #352
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- Posts: 3535
- Joined: Feb 5th, '05, 20:42
- Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1
Pitted Shaft
R Perlot
Just where on the shaft is the pitting? Is it only at the packing area or between the packing area and the prop. Anyplace else, hub to packing, or only outboard?
What metal is the prop shaft made of? What is the prop shaft diameter, maybe 1"? What metal is the prop? What metal is the rudder post?
O J
Just where on the shaft is the pitting? Is it only at the packing area or between the packing area and the prop. Anyplace else, hub to packing, or only outboard?
What metal is the prop shaft made of? What is the prop shaft diameter, maybe 1"? What metal is the prop? What metal is the rudder post?
O J
Clarification.
Sorry if I wasn't clear. Inside the stuffing box. On opposing sides of the shaft. Essentially, the pitted sections would be continually grating against the stuffing as the shaft turns.
It is a CD28, so the shaft is 1". It is a stainless steel shaft. No other visible problems that would affect performance. But I didn't take out the shaft or any of the other bearings, etc.. I'm mainly concerned about the constant replacement of the packing that will be required if the shaft just keeps tearing it apart.
It is a CD28, so the shaft is 1". It is a stainless steel shaft. No other visible problems that would affect performance. But I didn't take out the shaft or any of the other bearings, etc.. I'm mainly concerned about the constant replacement of the packing that will be required if the shaft just keeps tearing it apart.
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- Posts: 3535
- Joined: Feb 5th, '05, 20:42
- Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1
Pitted Shaft
RPerlot
This is a tough one to call without actually seeing what's going on. If there was any metal to metal grinding or gouging, there would be telltale rings or grooves around the entire shaft. Same thing goes for electrolysis, you wouldn't just have pits on opposing sides of the shaft. They would attack the entire circumference.
If I thought that the pitted section of the shaft was under water and denied oxygen, I might suggest that crevice corrosion might be the culprit.
The yard gave you some good advice to install a new shaft. $$$ I don't know your ability to work on projects such as these. If I were doing this for myself and was trying to save some bucks, since the boat is on the hard, I would pull the shaft, power brush the pits and fill them with high tensile SS rod or wire. Then I would turn down the proud fill on a lathe, smooth with emery cloth and crocus cloth and then power buff the area with jewelers rouge and tripoli. If it's more practical for you, take the shaft to a local metal shop to have them do the work professionally.
The next thing I tell you will probably elicit boos and hisses fron the vast majority of the readers, but what the hey. If you want to experiment some with the shaft still in place, clean out the pits and fill them as smooth as you can with JB Weld, or even thickset epoxy. Then lap with emery of different grades. That idea is truly wizz-bang per your request.
Hats off to Rube Goldberg, wherever you are.
O J
This is a tough one to call without actually seeing what's going on. If there was any metal to metal grinding or gouging, there would be telltale rings or grooves around the entire shaft. Same thing goes for electrolysis, you wouldn't just have pits on opposing sides of the shaft. They would attack the entire circumference.
If I thought that the pitted section of the shaft was under water and denied oxygen, I might suggest that crevice corrosion might be the culprit.
The yard gave you some good advice to install a new shaft. $$$ I don't know your ability to work on projects such as these. If I were doing this for myself and was trying to save some bucks, since the boat is on the hard, I would pull the shaft, power brush the pits and fill them with high tensile SS rod or wire. Then I would turn down the proud fill on a lathe, smooth with emery cloth and crocus cloth and then power buff the area with jewelers rouge and tripoli. If it's more practical for you, take the shaft to a local metal shop to have them do the work professionally.
The next thing I tell you will probably elicit boos and hisses fron the vast majority of the readers, but what the hey. If you want to experiment some with the shaft still in place, clean out the pits and fill them as smooth as you can with JB Weld, or even thickset epoxy. Then lap with emery of different grades. That idea is truly wizz-bang per your request.
Hats off to Rube Goldberg, wherever you are.
O J
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- Location: CD 25 #282: "Play it Again Sam" Fort Lauderdale, FL -
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don't skimp
M I C --- see you real soon, K E Y --- Why? because I took a shortcut
MOUSE!
If you plan on taking the boat back out in a few weeks or months because the "fix" didn't work, I'd say try the JB Weld trick as described, (but rightly so disclaimed) by OJ.
IMHO though, just as you wouldn't think of jury rigging your brakes or the fuel line in your car for obvious reasons, you shouldn't mickey mouse anything that could potentially sink your boat. I took a shaft from a 1969 power boat to be reconditioned by a machine shop, and it has served me well for 5 years of fairly heavy usage. Mine was simply worn down at the stuffing box area from 30 years of going round and round. The cost was $10 per inch of repair, which is not unreasonable. A new shaft would have been well over $400.
My $.02 worth of advice would be to do some research outside of your marina's grasp. Find a propulsion or marine machine shop and bring them your shaft. If you don't know of one, drop me a PM, there's one within walking distance of home for me! I can help you out.
![Exclamation :!:](./images/smilies/icon_exclaim.gif)
If you plan on taking the boat back out in a few weeks or months because the "fix" didn't work, I'd say try the JB Weld trick as described, (but rightly so disclaimed) by OJ.
IMHO though, just as you wouldn't think of jury rigging your brakes or the fuel line in your car for obvious reasons, you shouldn't mickey mouse anything that could potentially sink your boat. I took a shaft from a 1969 power boat to be reconditioned by a machine shop, and it has served me well for 5 years of fairly heavy usage. Mine was simply worn down at the stuffing box area from 30 years of going round and round. The cost was $10 per inch of repair, which is not unreasonable. A new shaft would have been well over $400.
My $.02 worth of advice would be to do some research outside of your marina's grasp. Find a propulsion or marine machine shop and bring them your shaft. If you don't know of one, drop me a PM, there's one within walking distance of home for me! I can help you out.
Madness takes its toll. Please have exact change.
- Scott MacCready
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- Joined: Feb 7th, '05, 08:47
- Location: CD 32
Replace the shaft!!!! (IMHO)
The shaft on a CD 28 is not very long and is not that expensive relative to other boat parts. Any other method still requires a lot of labor and a lot of cost:
The PSS shaftseal requires uncoupling the shaft from the engine. The advantage is that the steel donut set-screws to the shaft--the donut turns against a carbon-graphite donut--nothing is rubbing against the shaft. However, once you have the shaft uncoupled, why not pull it out and just replace the shaft? And the PSS shaftseal costs more than a new shaft.
I like the idea of adjusting the length of the rubber hose connecting the shaft log to the stuffing box, thus presenting virgin (i.e. non-pitted) shaft to the stuffing. However, you still have to uncouple the shaft in order to do this. And the new rubber hose is probably not a cheap item. So you will have purchased a (relatively) pricey new hose, performed a labor intensive job (uncoupling the shaft, recoupling, etc) and reinstalled a questionable shaft, all on a CD model with very tight access to that area.
I would shy away from repairing the existing shaft. I am not a metallurgist, but I would suspect the integrity of the shaft, and I would worry about breakage. Maybe the epoxy idea would work, but I wouldn't mess with it. The epoxy and the steel are going to expand at different rates as they heat up, and I'll bet the epoxy will break out, further damaging the packing, and causing leaks. OJ also had an interesting idea about a metal repair to the shaft. But it all seems like a lot of work to repair a short 1" shaft that may be of questionable integrity. The time and effort to repair the shaft would be better spent (IMHO) spec'ing out a new shaft.
I replaced my worn shaft two years ago with a 22" A19 stainless shaft. The shaft cost $140. I sent the old shaft and coupler to a recommended prop shop and they duplicated the shaft and faced it into the existing coupler for no extra charge. My guess is that the Cd28 shaft is about the same length or shorter.
All the work, uncertainty and messing about with jury rigs seems more costly to me in time, effort and money than just getting a new shaft and reinstalling the same gland with new packing.
The PSS shaftseal requires uncoupling the shaft from the engine. The advantage is that the steel donut set-screws to the shaft--the donut turns against a carbon-graphite donut--nothing is rubbing against the shaft. However, once you have the shaft uncoupled, why not pull it out and just replace the shaft? And the PSS shaftseal costs more than a new shaft.
I like the idea of adjusting the length of the rubber hose connecting the shaft log to the stuffing box, thus presenting virgin (i.e. non-pitted) shaft to the stuffing. However, you still have to uncouple the shaft in order to do this. And the new rubber hose is probably not a cheap item. So you will have purchased a (relatively) pricey new hose, performed a labor intensive job (uncoupling the shaft, recoupling, etc) and reinstalled a questionable shaft, all on a CD model with very tight access to that area.
I would shy away from repairing the existing shaft. I am not a metallurgist, but I would suspect the integrity of the shaft, and I would worry about breakage. Maybe the epoxy idea would work, but I wouldn't mess with it. The epoxy and the steel are going to expand at different rates as they heat up, and I'll bet the epoxy will break out, further damaging the packing, and causing leaks. OJ also had an interesting idea about a metal repair to the shaft. But it all seems like a lot of work to repair a short 1" shaft that may be of questionable integrity. The time and effort to repair the shaft would be better spent (IMHO) spec'ing out a new shaft.
I replaced my worn shaft two years ago with a 22" A19 stainless shaft. The shaft cost $140. I sent the old shaft and coupler to a recommended prop shop and they duplicated the shaft and faced it into the existing coupler for no extra charge. My guess is that the Cd28 shaft is about the same length or shorter.
All the work, uncertainty and messing about with jury rigs seems more costly to me in time, effort and money than just getting a new shaft and reinstalling the same gland with new packing.
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- Joined: Mar 7th, '06, 18:30
- Location: 1974 CD 28 Meantime
I have been described as the cheapest man in the world-(by my wife) and I wouldn't screw with a pitted old prop shaft-assume you are working on someone else's boat-would you jeopardize their safety to save a few bucks? why would you compromise yours? this is a once in a lifetime deal-tell the boat yard to cut the old shaft and replace it with a new cutlass bearing and a dripless seal-that's what I ended up doing-I have no intention of spending my summer stuffed into the back of a CD 28 engine compartment-(now my wife complains I spend money on the boat but nothing else)-
Thanks.
Thanks for all your thoughts. I looked closer at it today. I don't think there is any room to expand the hose. There isn't one as far as I can see. The threaded houseing goes right into the hull.
I have the boat back in the water for the weekend holiday, but I think I'll take the advise to replace the shaft'
Auuuughh!! Another $800 estimate, including haul-out. It sucks that I hauled it out to paint the bottom but found the problem just before I needed to put it back in the water. So I have to pay for another haul-out.
RPerlot
CD28 #352
I have the boat back in the water for the weekend holiday, but I think I'll take the advise to replace the shaft'
Auuuughh!! Another $800 estimate, including haul-out. It sucks that I hauled it out to paint the bottom but found the problem just before I needed to put it back in the water. So I have to pay for another haul-out.
RPerlot
CD28 #352