[C320-list] stuffing box issues

[Rick Sulewski]

Concur with Jeff's approach. Consider that the boat was on the hard and the shaft and engine will endure the hull flexing while on the hard that may contribute to a leaking packing nut upon launching the boat since the packing was further distorted after it dried out. Since the boat has been in the water for a considerable length of time, tightening the nut is the next logical step.

If Jeff's solution option does not work, there is another option that requires some dexterity and second pair of hands. You could consider adding a ring of Teflon stuffing packing material and some Teflon lubricant (green goo like paste). I am anticipating that your present stuffing has already been compressed and there is ample space to add a new narrow ring of packing material. The trick is to loosen the packing nut expecting water to flow into the bilge (so a working bilge is a must) so a second pair of hands is necessary to stem the water flow with a rag. Could also use some thin plastic sheeting (dry cleaning bags?) stuffed into the outermost edge of the shaft log immediately after the nut is moved forward toward the engine.  The water poses no risk as long as you can control the flow and reinstall the packing nut, making sure not to take your time and avoid cross threading it on the shaft log, which should not be a problem since the existing packing in the nut will pretty much keep the nut aligned on the shaft as you return the nut toward the shaft log.

It pays to always cut the extra packing ring and test fit the ring against the shaft before removing the nut. It will take only a couple of minutes to remove the nut and install the additional ring of new Teflon impregnated packing into the existing packed nut and then smear the shaft with the Teflon lubricant at the edge of the shaft where the nut will be returned (that area of the shaft that remains exposed near the log ahead of the second pair of hands holding back the water flow). If by chance an existing ring of packing material loosens up and can be easily removed when you remove the nut from the log, you may be able to also replace that older ring with a newer ring in addition to the additional ring. So, having a second ring of packing ready may prove to helpful. The combination of the additional ring(s) of packing and the Teflon lubricant is the next best option to the eventual move to GoreTex packing, rather than the more expensive options.  Could go with a narrower 3/16ths packing ring vs. 1/4 inch width. You may even find that this solution to extend the need to repack the shaft nut for another 3-5 years with annual snugging of the nut as the packing materials slowly wears.

I now use GoreTex on our 320 after experiencing 15 years of a nearly dry bilge with the annual addition of some Teflon lubricant combined with the older Teflon impregnated packing. Added a new ring of packing every 3- 5 years produced an almost dripless shaft. Periodic monitoring/maintenance of the cutlass bearing and checking/adjusting the shaft alignment also contributes to a lower incidence of shaft log leakage. I found the simple solutions often worked best vs.  the more expensive and complicated options. Even an expensive dripless gadget also require periodic maintenance and poses even greater catastrophic consequences if there is a seal failure. 

Rick
My-Ria 1995 C320 # 277

-----Original Message-----
From: c320-list-bounces at lists.catalina320.com [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Jeff Hare
Sent: Wednesday, April 10, 2013 11:24 AM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] stuffing box issues

I would tighten the stuffing box.  Before doing that, spray the threads with a penetrating oil and let it sit for a while,  then use a small wire brush to clean the visible threads on the stuffing box.

If you can loosen the narrow locking nut, back that off and clean the threads up close to the packing nut (the big one).

Then tighten the packing nut until it stops leaking. Make sure that the prop shaft still turns by hand and then tighten the locking nut and retest that the shaft turns and it doesn't leak.

If you run the engine in gear for a while, see if the nut is getting too hot to keep your hand on.  If so, you'll want to loosen it very slightly.  It is ok to get pretty warm when motoring fast, but not too hot to touch.

Next year, try GFO brand dripless packing braids.  They're a black goreTex material that works really well and doesn't dry out.

Jeff

Barbara Uhlman <uhlman at sbcglobal.net> wrote:

>Hey, gang,
>
>I believe this discussion has appeared earlier, but I was not able to 
>find it on the site.
>
>I have a several of questions re. the above.  We have developed a leak 
>in the stuffing box area.  The boat was on the hard from April to the 
>beginning of December of last year and a diver told us that the 
>stuffing box had dried out and shrank during those hot months in the 
>Florida sun.  Hence, the leak.  We had it tightened, but it still leaks 
>considerably more than what it did on a northern lake..
>
>This year the plan is to leave the boat in the water til mid July or so 
>at which time we will have it pulled again until the first of December.
>
>What to do now?  Tighten it more?  Replace the stuffing?  If so, with 
>which kind?  I don't want to do something that will dry out again 
>sitting on the hard next fall.
>
>I recall discussion on the dripless vs the more traditional stuffing 
>boxes.  Can someone give us some advice?
>
>Thanks.
>
>Barb Uhlman
>Whisper, #1158
>PuntaGorda, FL