New prop shaft seal.

[terabika]

I bought a boat on the hard and the dripless face seal needs replaced. They are expensive and I want nothing to do with them so I am looking at alternatives. Volvo has a nice seal but I like this one as extra lip seals and circlips can be placed on the shaft so that seals can be replaced with the boat in the water. And it is inexpensive. Thoughts? I was trying to add a photo of it but it asks me for a URL for my photo? Am I not allowed to put a photo from my computer on this?

https://www.d21ent.com/product-p/d21-001.htm

[stormalong]

Aluminum has no place in close proximity to a bronze shaft log in a salt water environment.

What make is the dripless face seal. A PSS only needs the bellows replaced. If the face needs re-polishing it is easily done on a lathe.

[terabika]

Originally Posted by stormalong

Aluminum has no place in close proximity to a bronze shaft log in a salt water environment.

What make is the dripless face seal. A PSS only needs the bellows replaced. If the face needs re-polishing it is easily done on a lathe.

There is no bronze shaft log if I use this. It uses the typical rubber hose to the fiberglass hull.
I cannot determine what make it is yet because I'm having trouble getting the shaft loose from the coupler. I have thought about using valve lapping compound and turning the prop by hand to lap the stainless and carbon faces together. I would prefer to get rid of it!

[stormalong]

Originally Posted by terabika

There is no bronze shaft log if I use this. It uses the typical rubber hose to the fiberglass hull.
I cannot determine what make it is yet because I'm having trouble getting the shaft loose from the coupler. I have thought about using valve lapping compound and turning the prop by hand to lap the stainless and carbon faces together. I would prefer to get rid of it!

There is a tube molded into the fiberglass. The hose it attached to it. That tube will be bronze. That is what a shaft log is.

What kind of boat did you buy? The supplier you linked too appears to deal in trailered hydroplanes. Is your boat going to live on a trailer or in the water?

You get what you pay for. That cheap shaft seal will require frequent replacement. How much will you pay to haul your boat to do that replacement?

[stormalong]

If it is carbon against stainless and it has a bellows hose behind the carbon it is probably a PSS. You don't lap them together. The difference in hardness between the two surfaces will just wear away the carbon and do little to the stainless. Chuck the stainless in a lathe and, depending on the condition either skim cut the ring or just use wet or dry sandpaper to clean it up. You do not need to do anything to the carbon. It is soft enough that it will polish itself.

You sound like someone with some mechanical skills but you are lacking in experience with this kind of seal.

Please post the make, model and length of the boat in your profile, also your location. People that will respond to your questions can answer them better if with that info.

[hlev00]

The Volvo works great on my 42’ sailboat. I’ve never heard of a complaint from others either.

[terabika]

Originally Posted by hlev00

The Volvo works great on my 42’ sailboat. I’ve never heard of a complaint from others either.

That is probably what I am going to go with. Tell me about greasing the lip. How often do you do it? Is it cumbersome to get to it? I understand there is a plastic piece that aids in this task. It just snaps over the crop shaft? Thanks!

[marcjsmith]

yeah the c clip looks nice and easy. but you still have to separate the shaft from the coupler, and maybe even slide the shaft out some to get clearance for the seals to slip on. not something I'd want to try to do while still in the water.

fwiw i'm finally replacing my PSS with a new one next month. I've owned the boat 4 years and recent receipts from the PO have me thinking its about 20 years old. Its just now starting to drip a little under hard acceleration.

Yes I know I've been on borrowed time given its a 6-8 year service interval. nothing about the face seal typeof shaft seal would worry me. plus side is no wear on the shaft from packing or lip seals. down side is the service interval.

[terabika]

Originally Posted by marcjsmith

yeah the c clip looks nice and easy. but you still have to separate the shaft from the coupler, and maybe even slide the shaft out some to get clearance for the seals to slip on. not something I'd want to try to do while still in the water.

fwiw i'm finally replacing my PSS with a new one next month. I've owned the boat 4 years and recent receipts from the PO have me thinking its about 20 years old. Its just now starting to drip a little under hard acceleration.

Yes I know I've been on borrowed time given its a 6-8 year service interval. nothing about the face seal typeof shaft seal would worry me. plus side is no wear on the shaft from packing or lip seals. down side is the service interval.

I figured a way around having to take the shaft out. I would merely put some extra lip seals and clips on the shaft and wrap some tape around them such that I could pull the old seals out cut them to take them off and then just slide the new seals in. The Jeff has about 4 in of blank space that the extra seals could sit on. I could actually put seven or eight on there pretty easily with clips space in between them and if I didn't need to use a clip I could just bend it off and throw it away.

[barnakiel]

I had various seals on various boats - from grease packed glands all the way to that "dripless" PSS nonsense.


In my own boat I have the rubber boot Volvo seal. Can tell you this - does not leak and requires only limited maintenance. Life at least 10 years (manufacturer's recommend) - but the old one was easily twice that old, and the recent one is 6 years old now and looks new. And it DOES NOT DRIP.


Our shaft 25mm



2c


b.

[hlev00]

Originally Posted by terabika

That is probably what I am going to go with. Tell me about greasing the lip. How often do you do it? Is it cumbersome to get to it? I understand there is a plastic piece that aids in this task. It just snaps over the crop shaft? Thanks!

I bought a small tube of the volvo grease. Many just use a silicone or PTFE grease. To inject, use a plastic straw from your favorite fast food. Squeeze some grease into the tube, squish that end down to fit between the lip and the shaft, then push the grease out of the straw. I do this each Spring. When launched burp the gland by deforming the lip just enough to let air escape and a bit of water to come out.

My boat has a raw water feed through its own through hull to a 3/8" nipple on the shaft tube. The thru hull has a scoop facing forward to force water into the hose and out the cutlass. This is pretty standard though IIRC the Volvo instructions are not absolute about this for a boat traveling the speed of a displacement sailboat.

[MicHughV]

Not all shaft logs are made from bronze.

[stormalong]

Originally Posted by MicHughV

Not all shaft logs are made from bronze.

Maybe not but most are. Of all the metals that can be immersed in salt water, and salt water is also an assumption on my part, aluminum is the worst.

Look at all the problems with sail drives and corrosion. Builders install sail drives to save money and space and their customers pay for it forever.

[Bowdrie]

If your boat has an actual "tube" that the shaft goes thru you can install a Zerk fitting just behind an old-fashioned packing gland and pump the whole tube full of grease, (the wheel bearing grease they use on boat trailers that get backed into water works well, not something with graphite).
The packing will last forever with little compression and no leaks, and the shaft/tube won't get full of sea-monsters.
You give it a shot of grease once in a while and never worry about the failures that the new-fangled devices all end up with at some point, (and require expensive haul-outs to fix).
All the lip seals, carbon rings, bellows, and stainless gizmos were never a great thing, they're just a pacifier for those who became horrified that some water actually got in the boat when the engine was running.

[terabika]

Originally Posted by stormalong

If it is carbon against stainless and it has a bellows hose behind the carbon it is probably a PSS. You don't lap them together. The difference in hardness between the two surfaces will just wear away the carbon and do little to the stainless. Chuck the stainless in a lathe and, depending on the condition either skim cut the ring or just use wet or dry sandpaper to clean it up. You do not need to do anything to the carbon. It is soft enough that it will polish itself.

You sound like someone with some mechanical skills but you are lacking in experience with this kind of seal.

Please post the make, model and length of the boat in your profile, also your location. People that will respond to your questions can answer them better if with that info.

I do not have a lathe and no one is conveniently close by. However, I did contact pyi to validate my idea. My idea is to flip the stainless collar 180*.
The Gent at pyi suggested I put some 600 grit paper wet or dry the top a sheet of glass and move the carbon over it to get it to a flat face. Because of vapor deposition there is some funk on the good side of the stainless collar,. I will do that for the collar as well. He suggested that when the faces have a good seal that one can take a tiny bit of water and put it on the stainless steel face and set the Carbon atop it and spin it and then lift straight up. There should be a suction between the two pieces, the wonders of surface tension of water. The shaft is a little too rough for me to feel comfortable switching to something that depends on the surface of the shaft for a seal so I am going to buy the kit with the new Bellows and set screws and clamps. As soon as possible I will put a Volvo seal on, likely my next haul out. Given how abraided the face on the one side is, I'm not very impressed with this system. I know a lot of people seem to have good luck with them but I will rid myself of it as soon as I can.