Bearings

[iggy]

Hi everyone!

I have asked about what to have the factory install on a new Cutwater C-30.

A lot have suggested to go with the dripless bearings. Other than then having a dry bilge, why? I have always owned a boat with I/Os, but I somewhat understand the difference.

From what I have been reading, both have there upsides and downsides. What I though was interesting is that my friend has a Nordhaven and they use a stuffing box. Due to the fact that a stuffing box if leaking more than normal can be easily be tightened and than fixed later and a long life. The dripless is more likely to sink a boat when it does fail. It can not be tightened per-say.

Not try to argue at all, but trying learn about them. Please, your thoughts on this!

 

[NorthernFocus]

Presumably you're talking about a dripless stuffing box aka mechanical shaft seal. Conventional wisdom is that the traditional stuffing box requires more attention but is easier to "fix". Shaft alignment and/or too much clearance in the cutlass bearing can compromise a dripless seal. Then again those two things cause most of the trouble with packing. If you pay attention to and take care of the running gear they both work fine. If you don't do that they will both be problematic. I'm heading into the fifth season since I last replaced packing.

 

[iggy]

Presumably you're talking about a dripless stuffing box aka mechanical shaft seal. Conventional wisdom is that the traditional stuffing box requires more attention but is easier to "fix". Shaft alignment and/or too much clearance in the cutlass bearing can compromise a dripless seal. Then again those two things cause most of the trouble with packing. If you pay attention to and take care of the running gear they both work fine. If you don't do that they will both be problematic. I'm heading into the fifth season since I last replaced packing.

Basically, that's what I have been hearing. My friend went 15 years before repacking. As he said, "there is something to be said to have a dry bilge too."

I am leaning towards the dripless and it does not look to hard to replace. More of a pain and the cost of parts are low.

One thing I am going to do anyways, is install an extra bulge pump. In ether case, if the stuffing box or dripless lets go. That a lot of water coming in.

 

[NorthernFocus]

...if the stuffing box or dripless lets go. That a lot of water coming in.

Not sure what you mean by "let go". It is virtually impossible for conventional packing to fail catastrophically. Having a hose clamp fail on the bit of hose connecting stuffing box to shaft log is the only practical risk of catastrophic failure. And both methods of sealing share that feature. Dripless seals by design are more susceptible to fail suddenly but even then typically only if something else has happened to the shaft.

Honestly you are way overthinking this. If you simply practice good seamanship and check your engine room multiple times each day there's little to worry about.

 

[knotflying]

Get the boat and you should be fine with your stuffing box packing for possibly 1,000 hours. After that you can decide which way to go. Keep it simple.

 

[iggy]

...if the stuffing box or dripless lets go. That a lot of water coming in.

Not sure what you mean by "let go". It is virtually impossible for conventional packing to fail catastrophically. Having a hose clamp fail on the bit of hose connecting stuffing box to shaft log is the only practical risk of catastrophic failure. And both methods of sealing share that feature. Dripless seals by design are more susceptible to fail suddenly but even then typically only if something else has happened to the shaft.

Honestly you are way overthinking this. If you simply practice good seamanship and check your engine room multiple times each day there's little to worry about.

Get the boat and you should be fine with your stuffing box packing for possibly 1,000 hours. After that you can decide which way to go. Keep it simple.[/quote

You are both right and thank you!! Why spend the extra money now.