Stuffing box and prop shaft

[duanegeib]

Here is a picture of my propeller shaft and stuffing box. I have two questions. The first question is, Does anyone know the type of maker of the stuffing box. I have researched extensively about repacking it, but would like to find the maker so I can research it before i endeavor to repack it. I would be doing it while in the water.

Second question. The metal strap touching my prop shaft. Is it to ground the propeller. Notice it is attached to a green wire and then touches the prop shaft. I need to replace it. What type of metal would I buy to replace it.

 

[Comodave]

Here is a picture of my propeller shaft and stuffing box. I have two questions. The first question is, Does anyone know the type of maker of the stuffing box. I have researched extensively about repacking it, but would like to find the maker so I can research it before i endeavor to repack it. I would be doing it while in the water.

Second question. The metal strap touching my prop shaft. Is it to ground the propeller. Notice it is attached to a green wire and then touches the prop shaft. I need to replace it. What type of metal would I buy to replace it.

Don’t know who made that log but we had them in our last boat. Pretty easy to repack but I had some trouble getting the old packing out. I had several of the picks made to get the packing out but they wouldn’t work. Finally used some long screws to pull it out. I put in Duramax packing since you can adjust it so it doesn’t drip at all.

The metal strap is for the bonding system. They sell grounding straps for that purpose.

 

[PhilPB]

Don’t know who made that log but we had them in our last boat. Pretty easy to repack but I had some trouble getting the old packing out. I had several of the picks made to get the packing out but they wouldn’t work. Finally used some long screws to pull it out. I put in Duramax packing since you can adjust it so it doesn’t drip at all.

The metal strap is for the bonding system. They sell grounding straps for that purpose.

The metal strap, is it normal to have a strap contacting the drive shaft like that?

I don't have that but I do have a ground wire attached to the coupling (not sure of what I'm calling the coupling is actually called) where the shaft exits the boat.

 

[duanegeib]

Thank you, Comodave, for swift reply. Sine i bought my 42 Jefferson Sundeck I have followed your threads and learned much…thanks!

 

[SeaDogAK]

My old Tollycraft 37 had a strap on the drive shafts that looked just like that.

 

[JMcJ]

Packing is dead easy to replace. I would look at YouTube, but some pointers. Do when boat is out of the water. To remove the packing I use a long shaft small blade screwdriver on which I’ve bent the last 1/2” to 90 deg. You need to ascertain the packing size which you can do by using drill bits to fit between the shaft and the housing. Then make 5 separate rings of packing. Easy to do using the shaft itself as a form. Cut each at 45 deg with a (fresh) sharp razor blade. Then when installing, stagger the joints. Take care pushing them home…a short length of plastic pipe split lengthwise helps. Take your time adjusting the amount you tighten.

Why are you changing the ground strap? I have not seen one slung under the shaft before. If it has a bronze contact piece, it should be OK. It may be preferable to have it making contact on the top of the shaft, which would make it easier to adjust and monitor the contact pressure. It is not sufficient rely only on a grounding wire connected to the fitting because it would be insulated from the shaft by the packing.

Good luck.

 

[SIBERNUT]

Plenty of strap left. Slide it in a little & re-screw.

 

[SteveK]

The metal strap should have a brush (hard material) at the end to maintain constant electrical bond back to the transom zinc to protect shaft and prop. This is in addition to shaft mounted zinc.

 

[Max1]

If your stuffing box is below the water line, you will have tons of water rushing in when you are pulling out the old stuffing.

It is better to do it in drydock.

There is a youtube video of some old salt swapping it out in the water and he does not panic when the water rushes in, but i would be!!

The problem I had with mine was it was hard as a rock, especially the deepest packing. It took a few tries to get it out.
.
I used the standard pick set sold at hardware shops.

 

[Max1]

I found the video.

 

[boomerang]

The packing gland looks like a Buck Algonquin. Just have the new packing precut and you won't get that much water in the bilge changing the old packing. Clean up the threads beforehand to help everything go smoothly. You won't sink.

 

[Comodave]

There is actually less water that will come in than you think. Have several rags on hand to stuff in if you need to take a break. Agree on having the packing cut before hand. I also use a section of PVC that is the same ID as the shaft OD. Cut the PVC lengthwise into 2 pieces. Then you can use them to push the new packing into the log. It helps the packing stay even as you push it into the log.

 

[Delta Riverat]

Yeah, my bilge pumps could take care of that easy. I'd check them before I started.

As long as the batteries were up.
And the pumps didn't clog.
And the hose didn't fail.
Or the pumps.

Yeah, could do in water but lot's of room for Murphy.

 

[Comodave]

Yes, it is a good idea to do a test on the bilge pumps just before repacking the shaft log in the water.

 

[lwarden]

That shaft log hose looks pretty bad from the picture. I would be thinking of doing this on the hard and refurbish or replace the stuffing box depending on how it looks internally.
Also, replace the hose and put on some better hose clamps, like AWAB or Scandvic. The ones on there with the gear drive teeth all the way through are prone to failure.

 

[tiltrider1]

I see a bellows and clamps that need replacing. There is corrosion on the clamps which if left untreated will break. The bellows looks like it’s 35 years old. NotHing looks like it will fail tomorrow but it is definitely time to replace.

I see enough oxidation build up on the stuffing box that it might take a little effort to separate. Might come apart with a little pry bar action but I wouldn’t put too much pressure on such an old bellows.

Ideally I would like to pull the boat, replace the bellows, bead blast the stuffing box and replace the stuffing instead of just adding more stuffing.

If the stuffing box has run out of adjustment, is leaking and pulling the boat is not an option, I would just add another ring or two until I could do things right.

What I wouldn’t do is pull all the old stuffing out, add 3 new rings and tHink the job is finished.

 

[MichaelD]

Don’t understand need for the brush on the shaft. It should be grounded through the engine block, and hopefully has zincs mounted directly outside.

 

[Steve DAntonio]

If it's an Asian-built vessel, the stuffing box is likely locally sourced, so you are unlikely to find a manufacturer. In most cases, the packing diameter is a function of the shaft diameter. While it's not universal across all stuffing box designs, this chart is a good starting point (from an old copy of the East End Supply catalog).

The shaft brush, or what's left of it, is designed to provide cathodic protection to your shaft and propeller, via the bonding system, which is presumably connected to a zinc. It would also provide some measure of stray current corrosion protection. In reality, few of these inexpensive, carbon or bronze "brush", off the shelf shaft brushes achieve the require sub one ohm resistance required for cathodic protection. This one especially, with the stainless wand, is very unlikely to meet that requirement.

You could replace it with a similar version, it won't hurt, but it's unlikely to help unless you are willing to go to an expensive silver slip ring type brush arrangement, detailed here https://stevedmarineconsulting.com/bonding-systems-and-corrosion-prevention/

Also, the tapping screw securing the wire to the brush's wand is not ABYC compliant, tapping screws cannot be used for electrical connections.

More importantly, make certain your shaft is set up with its own anodes, which are changed as soon as they reach 50%, these will protect the shaft and prop, especially if the latter is manganese bronze, as many props are.

 

[Nepidae]

Stuffing box

DO NOT USE ANY PICKS OR SCREWDRIVERS AGAINST THE SHAFT.

It is too easy to score the shaft and then you do have a problem.

At Defender Marine the have caulk removal tools. They have a corkscrew on a flexible shaft that will get into any caulk left in the gland.

I agree that you should haul the boat and do a full replacement of the gland material.

It wouldn't surprise me that the strut bearing would need to be replaced as well.

Finally, while out of the water the props could also be checked balanced and any knicks take out.

If your headed down the road do it right.

IF by any chance this is a twin screen do both sides regardless of what the other side looks like.

Then when all done make an entry in a dated log as to the work that was done. Obvious reasons as to why.

Good luck.

 

[Steve DAntonio]

Repacking instructions here https://stevedmarineconsulting.com/conventional-wisdom-for-conventional-stuffing-boxes/

 

[gilbertpark]

I have similar stern glands on my boat. You don't need to replace them, my local engineer took the shafts out, took the glands off, refurbished the metal parts and put new hoses on them and hose clips. Good as new and much cheaper.

I did have the packing replaced before that while the boat was in the water. No big deal about water ingress.