Adjusting drip rate for stuffing box

[baz]

Subject: Adjusting drip rate for stuffing box

My boat is a new 2019 R29 CB NW Edition -- 3 month old from factory and somer 30 engine hrs.

I had discovered the drip rate from my stuffing box with shaft stationary was around 40 drips per minute. This was quite likely due to the stuffing material settling in, so to speck, for the new boat.

I purchase two wrenches of appropriate size and handle lengths

https://www.amazon.com/gp/product/B0009 ... UTF8&psc=1

to use for unlocking the lock nut (the smaller one) and stuffing box nut (the large one).

Trying to turn the skinny lock nut clockwise was a PITA and I eventually gave up on that. I decided instead to tackle loosening the big stuffing box nut (anti-clockwise) by laying down on the engine facing aft (belly down) and using the wrench and a hammer to gently loosen the big nut..... and this did the trick and could hand rotate the locking nut back a couple of threads.

After several attempts I was able to get the stuffing box positioned to get no drips with shaft stationary and around 3 to 5 drips per minute with the shaft rotating.

I will b e checking this drip rate once per month from now on.

 

[TugScout]

Hey Barry,

How long did you run the boat and at what speed after each adjustment? Also, do you know in total how much you tightened the packing gland?

I'm using your experience as the baseline for adjusting mine. 🙂

Many thanks,
Mark

 

[baz]

Hey Barry,

How long did you run the boat and at what speed after each adjustment? Also, do you know in total how much you tightened the packing gland?

I'm using your experience as the baseline for adjusting mine. 🙂

Many thanks,
Mark

First... I found that releasing the big stuffing box nut was the best rather than trying to loosen the locking nut to begin with.

1) With the locking nut backed off from the stuffing box nut I adjusted (tightened clockwise as viewed from forward to aft) the stuffing box nut (the big nut) ever so slightly each time. I would say a fraction of the nut's flat side. The factory setting made a yellow painted line on the locking nut and stuffing box nut so that any final adjustment amount could be visibly seen by the gap between the two yellow markers. It took me 5 adjustments to go from around 15 drips per minute to the 5 drips per minute with shaft rotating. My very first adjustment gave me zero drips with shaft stationary, but too many drips with shaft rotating. Laying down on my belly on top of the engine facing aft to access the stuffing/packing gland with both hands was doable, but getting up from this position was a PITA. I had to rotate myself, inch myself aft a bit so my feet were firmly on the forward part of the beauty covers and then heaving myself up to a standing position.

2) My goal was; no drips with shaft stationary with engine running in neutral, and less than 6 drips per minute with shaft rotating and engine in forward at first throttle detent.

3) The technique I used for having the engine running with throttle in forward at first detent was to have the boat securely tied at its stern to a large sturdy cleat and with the boat stem about 12" from the dock lip. I would place the boat in forward, made sure all was good with the stern tie up, walk back to the opened engine hatch, and using a good strong flashlight and my iPhone stopwatch measuring the drips per minute. I would say, I left the boat's engine running in forward for around 5 mins to be absolutely sure the drip rate was constant.

I would have liked to get to 3 drips per minute with shaft rotating, but a quick call to RT convinced me I was good at 5 dpm. 🙂 ...with a periodic monthly check on the drip rate.

 

[baz]

Let me add one more piece of advice for those that intend to lay down on the engine's beauty covers to gain easy access to the stuffing box nuts.

Place one of those MOB square cushions on the aft end of the engine's beauty cover and maybe an extra blanket on top of this. Then laying down on your belly with your chest on the blanket + cushion and facing the stuffing box below this will protect your chest from being hurt/bruised. Your legs/feet will likely dangle back through the cabin door so a blanket placed over the door's threshold would make the foot's ankles less prone to damage/scratches/bruises as well.

 

[Admiral S]

Let me add one more piece of advice for those that intend to lay down on the engine's beauty covers to gain easy access to the stuffing box nuts.

Place one of those MOB square cushions on the aft end of the engine's beauty cover and maybe an extra blanket on top of this. Then laying down on your belly with your chest on the blanket + cushion and facing the stuffing box below this will protect your chest from being hurt/bruised. Your legs/feet will likely dangle back through the cabin door so a blanket placed over the door's threshold would make the foot's ankles less prone to damage/scratches/bruises as well.

We keep several moving blankets on the boat just for this type of exercise. We also use them to cover the floor if we are doing any type of work or expect higher than normal traffic through the boat

 

[Trisailor]

I had the adventure of adjusting the stuffing box drip rate yesterday. It has been a moving target since having the cutless bearing and shaft packing replaced last fall. I had a 3 to 4 drip per minute at rest with out the shaft turning. It took some PB Blaster and a couple of pipe extensions on the wrenches to gently loosen the locking nut. The main nut then only needed to be tightened about 1/8 of an inch (very small adjustment) to stop the drip, after which I had to tackle rebuilding the Y valve for the holding tank since it also was dripping into the bilge. Fortunately that was only an occasional drip, just enough to know something was not right.
Instead of putting the cushion and blanket on the engine cover to lay on, I had a 60 by 18 in wide piece of pine shelving to spread perpendicular across the engine opening. It worked well and was the same level as the rest of the cockpit floor so it was easy to find room for legs and tools. Unfortunately it was still an effort getting up and down from the shelf, I'm not as limber as I once was....however once up it was an easy matter to get to the fridge for a rewarding cold beverage.