My Commander is the first boat I've owned with stuffing boxes and while they are conceptually simple, I'm hear to tell you they can be a pain in the but. But I think I've finally figured them out, so I figured I'd share what I've learned in case another 'new-to-stuffing-boxes' owner happens along.

Before launching the boat for the first time the stuffing box tubes were rebuilt and therefore the stuffing boxes were re-packed. What I now know is that they were very over tightened.

As we started our 450 mile journey to our home port I could smell burning wax, which is a bad sign, but was told by the marina was normal for freshly packed shafts. First touch of the packing nut, and hissing water told me that was not normal at all! So all through our trip home I would check the temperature of the packing by hand and adjust. I could never seem to find the proper position for the nut. Either water was pouring in, or the shaft ran too hot. I adjusted the nuts so many times that half way home I picked up some extra cotter pins in case the current ones broke from bending back and forth so much. I continued to fight with this all last season, tighten, loosen, tighten, loosen...

I finally have it dialed in and both shafts drip ever so slightly at the dock. If I hold my hand under the nut for 60 seconds, I might feel one drop, but often nothing. I have temperature probes on both nuts (Maretron TMP100 with a DSM410 display) so I know exactly what temperatures they run. Cruising around at 1100-1300 RPM, they are within a few degrees of each other and in 68 degree water they run around 94 degrees. I would think as the water warms up, the nut temperature will rise equally. So right now I have a 26 degree differential. I had seen temps pushing 200 degrees at one point on one shaft.

Key things I think I've learned:

 - Adjusting the stuffing nut just before heading out seems to work best. It seems that after running on the new setting for a while the stuffing will re-seat / re-shape itself. It might leak a lot initially after tightening or loosening, but significantly slows or stops after running the boat for an hour or so. I mention this because in the past I'd come back to the dock (or set anchor) and then make an adjustment, which would cause a lot of water to come into the boat so I'd second guess that setting and tighten it back up.

 - 25 degrees over water temperature seems to be a good temperature to shoot for. I haven't seen any real data on exactly what the right temperature should be, but I can tell this is much better than the 150-165 I was seeing when I first put on the temperature sensors - and I'm not flooding my bilge.

 - increasing your RPM (to a point) actually cools the stuffing box down. I suspect the higher RPM allows a faster flow of water. In my case, jumping from 900 to 1200 RPM decreased the nut temperature around 10 degrees (this is when they were still too tight and were running 150-160 degrees)

 - I'm a data guy, and knowing exactly what temperature my stuffing boxes are running is very re-assuring. I no longer have to run down, open the floor to physically check the temperature. I'm sure a lot people never even look at their stuffing boxes once they are set, but once you've done it several times every trip out for a year, just glancing up and seeing a number is awesome. The TMP100 has 6 inputs so I still have a few left that I can use for things like generator water temperature, since mine has no gauges.

Views: 222

Reply to This

Replies to This Discussion

Know the feeling.  At last haul I had a shaft replaced and the yard repacked both boxes.  I was reluctant but this is not super science and not the first repack for the yard.  Same problem you found, overtightened, melting wax below packing gland and loosening wasn't helping, the wax was out of the flax, the flex was probably trashed and the customer was not happy.  Fortunately the yard agreed to pull packing repack, leave with slight drip and customer's responsibility to make further adjustments no charge.

Fortunately on the 35 I can raise one hatch and shoot both glands with the temp gun.

Sounds like you have the same style stuffing box my 27' has...Does it have little holes drilled all the way around where you line them up and put a cotter pin in? Luckily my htaches are right there so I used some 12ga wiring to make them more adjustable. But I had the same problem, either leaked a ton of water or because burning hot. Ne zdx t time I get my boat ready for the water I will replace my aging stuffing boxes with the kind that has a jam nut.those are far more adjustable...

Yes, mine have I think 8 holes around the nut. Your problem is exactly what I experienced. Try loosening the nut by 1 or 2 holes next time you go out (if they are getting too hot right now). Do it before you leave the dock - they will leak a lot probably - like not a drip but more of a dribble. Ignore that and drive your boat for an hour. Shut it down and see if it's slowed to a drip or nothing. I swear, that simple order of operation change made all the difference for me.

Steve said:

Sounds like you have the same style stuffing box my 27' has...Does it have little holes drilled all the way around where you line them up and put a cotter pin in? Luckily my htaches are right there so I used some 12ga wiring to make them more adjustable. But I had the same problem, either leaked a ton of water or because burning hot. Ne zdx t time I get my boat ready for the water I will replace my aging stuffing boxes with the kind that has a jam nut.those are far more adjustable...

My stuffing boxes aren't too bad to get to, but not super simple either. One I have to pull up carpet in the midship cabin and the other I have to wedge up the floor in the aft head

One of my shafts is brand new and the other is fairly new as well - that's why I've been so on this, I really didn't want to ruin the shaft.



Timothy "Tim" Miller said:

Know the feeling.  At last haul I had a shaft replaced and the yard repacked both boxes.  I was reluctant but this is not super science and not the first repack for the yard.  Same problem you found, overtightened, melting wax below packing gland and loosening wasn't helping, the wax was out of the flax, the flex was probably trashed and the customer was not happy.  Fortunately the yard agreed to pull packing repack, leave with slight drip and customer's responsibility to make further adjustments no charge.

Fortunately on the 35 I can raise one hatch and shoot both glands with the temp gun.

I would bet there is an instructional info bit in the super disc about servicing and adjusting stuffing boxes. Intuitively, knowing that the driveshaft must turn, I would start with it snug/hand tight and then slowly tighten until you get a drip a minute. But, I am not the expert. CCCC President is an expert.

Agree, and that advice is available in many places and is the correct way to approach it. The problem is really how do you recover from an over tightened stuffing box that has been run for a while? It's maddening trying to back off the nut without filling the bilge with water. 

Edward "Ed" STONE said:

I would bet there is an instructional info bit in the super disc about servicing and adjusting stuffing boxes. Intuitively, knowing that the driveshaft must turn, I would start with it snug/hand tight and then slowly tighten until you get a drip a minute. But, I am not the expert. CCCC President is an expert.

Just my two cents when it comes to repacking shafts, I use the Gore tex GFO shaft packing. It is virtually drip free as the packing contains graphite impregnated material that is then kept together with a teflon coating and best of all, no wax. You can tighten to a point where you have no drips and not have to worry about heat or scoring your shafts. Try it and then put your IF temp gun on it you wont be disappointed. 

From Boat US: http://www.boatus.com/boattech/casey/stuffing-box.asp

I adjust mine while at the dock. Mine is the type pictured, adjusted by tightening the two nuts. The only trouble I have had is when the stuffing collar was not perfectly centered on the shaft. With a bright light and the engine idling in gear, it was easiest to get the thing adjusted and centered.

That's my plan for the next time I repack - but now that I've got them working well - I'm not touching anything.... :-)

Kevin McKinnon said:

Just my two cents when it comes to repacking shafts, I use the Gore tex GFO shaft packing. It is virtually drip free as the packing contains graphite impregnated material that is then kept together with a teflon coating and best of all, no wax. You can tighten to a point where you have no drips and not have to worry about heat or scoring your shafts. Try it and then put your IF temp gun on it you wont be disappointed. 


Use GFO - it's great stuff.

BUT BE CAREFUL! When you first install it, DO NOT tighten it up to a few drips per minute like you normally would. The following may sound like a lot of running and then slow tightening, but a number of forum members have tightened it too much at first and had it heat up too much and then it's impossible to undo that and you have to start over. Mine now runs cool and basically doesn't drip much at all. After I got it seated right, we put 6,000 miles on the boat with zero problems and very minor dripping.

WHen you first install it, just tighten it to one drip per second or more (that's lots of dripping).

Then go out and run it for 15 minutes. While somebody else pilots the boat, at hull speed or more, check the packing gland with your hand on the metal (it should be cool to slightly warm but not be too warm to be uncomfortable). GFO transfers heat to the metal gland more than waxed flax does. If it stays cool enough, back at the dock re-tighten it to one drip every 5 or 10 seconds. You may find that it has reduced dripping on its own during the run-in.

Then run it again, check warmth again and re-tighten again to one drip every 2 or 3 seconds. Again, it may have reduced dripping on its own during the run-in.

Then leave it dripping slowly and run it for a cruise or two, like a few hours or more of running. Then tighten it to one drip per minute at the dock. After a number of cruises you can check warmth and gradually tighten a little more until it hardly drips at all. After that, you're probably good for many years of almost dripless running.

Reply to Discussion

RSS

Club News

2018 Photo Contest Winner

The 4th Annual Chris-Craft Commander Club Photo Contest had more than 50 entries and selecting the winners was not an easy task. 

First place: submitted by Pat Chaps

Second place: submitted by Martin Krall;

Third place: submitted by Jeff Pacy.

To view all entries to this year's contest,         Click Here

________________________________________

The 2018 Chris-Craft Commander Club National Rendezvous is in the books and it was a great time!!

City of Mentor, Ohio

The city of Mentor, Ohio and the Lawnfield Inn & Suites were wonderful hosts.  A special Thanks to Rob Kneen, the local member sponsor, and Char Pike for the hours of hard work put in organizing and coordinating an amazing weekend. 

The Rendezvous Photo Albums can be accessed through the links below, as well as, under Library, Photo Albums.  We will continue to add links to other albums as they become available. Also below, you will find links to a couple articles written for the local newspaper.

Photo Album 1                 Photo Album 2  

Photo Album 3

Articles:

Chris-Craft Commander Club Celebrates Anniversary in Mentor

Chris-Craft Commander connoisseurs congregate at Mentor Lagoons Marina

_________________________________________

 

© 2018   Created by CCCC Webmaster.   Powered by

Badges  |  Report an Issue  |  Terms of Service