[C320-list] Dry bilge?

[Doug Treff]

Scott,

If your stuffing box is dripping that much when the engine is not in 
gear, it probably needs tightening. It should not drip at all (or VERY 
little) unless your engine is in gear. The drip rate you mention is what 
would be normal when the shaft is turning. If you are unable to stop the 
drips when sitting still, it may be time to repack the stuffing box.

See an excellent article on this topic by Don Casey: 
http://www.boatus.com/boattech/casey/stuffing-box.asp

There are different types of stuffing media available which advertise to 
be drip free. I have not used any of them so I will not endorse any 
product. Maybe some other members who have used these products will 
speak up.

Of course the most expensive option (and definitely drip free) is to 
switch to the PSS shaft seal, but this is a pretty big job. When I was 
contemplating the PSS, my mechanic told me that I would also need to 
replace my bronze prop shaft with Stainless Steel in order to do the 
job. I declined and went with traditional packing. On the C320, you will 
have to drop the rudder to get the shaft out. All these things start to 
add up quick, making this a potentially expensive job. Some people also 
don't like the PSS product because the rubber bellows is much more 
fragile than the shaft hose and if it splits or gets torn, your boat 
will sink. I have honestly never heard of this happening, but people do 
mention it. I have also heard that the bellows must be replaced every 
six years (per PSS website) which will naturally require the prop shaft 
to be pulled back, removal of the coupling, and a possible realignment.

My point is this: Each one of these packing systems is a compromise. On 
conventional systems you can repack every few years without having to 
pull the shaft. The compromise is a wet bilge. On the PSS system, you 
will have a dry bilge but will face the added expense of pulling the 
shaft to replace the bellows periodically. Your call.

My advice: get an estimate, taking into account all the things I 
mentioned above (replace shaft if yours is bronze, drop rudder, cutlass 
bearing replacement (might as well if the shaft is out) cost of PSS 
itself, etc. Show this estimate to your wife and let her decide if a dry 
bilge is worth that expense. She may just change her tune.

---
Doug Treff
September Song Hull #350
doug at treff.us

On 2014-11-20 07:09, Scott Westwood wrote:
> I have seen several notes on how to re-pack stuffing boxes etc...
> 
> I also have heard different takes on dripping and "drip less" vs.
> "dripless".  My wife "hates" water in the bilge with a passion.
> 
> Is there a truly safe way to get a dry bilge?  Cost/benefit analysis?
> You can but it would cost as muchas the boat etc???
> 
> Our box drips 3-5 drips/minute even at the dock.  Is this normal?  I
> hear it is for cooling underway etc...
> 
> 
> What thoughts are out there?
> 
> One concern we both have is the odd chance that we have a bilge pump
> failure (or battery failure) at the dock.  We have shore power but we
> often can't get to the boat for a month or so.  Worst fear is bilge
> pump failure and boat sinks.  I know it should not happen within a
> month or so but there is also the fear of wood deck damage if bilge
> water rises etc...
> 
> 
> Thoughts out there?
> 
> 
> Scott Westwood scottwestwood at bellsouth.netH (919)-362-8538C 
> (919)-618-7185