Prop Strut replacement

[skipper007]

My partner used my nifty underwater camera to take a nasty shot of our prop strut. What do you think?

Is my only replacement option the outfit in WA?

Any guess on boat yard hours for this job?

Thanks,
Skip

 

[Rhynie]

Skipper,
Finding one may also be an issue. I had to replace one on a Pearson 30; it had to be cast. There is an outfit in the NE that has a lot of the old molds for these; the actual part cost me about $400.00 plus the cutlass bearing.

It is also an good time to pull the shaft and have the stuffing box and connecting hose reworked, and then re-align the engine.

I think the whole operation ran me about 1 boat buck, but the boat was already hauled out.

 

[Cory B]

Yuck. If I remember right, the strut is glassed (and bolted?) in on the 32-2 under the fuel tank. If so, labor will not be cheap. I think theres a thread about it somewhere... may take some searching.

 

[ref_123]

Can be done

Went through it last spring for our 32-3. Yard manager was able to find a stock strut, so the piece itself was about $500; he also estimated about 24 hours of labor as they had to remove an autopilot and water heater to get to the grinding spot. In reality though they spent only about 15 hours as both are removed and attached easily (love my IsoTherm slim). So, it's not cheap, but if yard can find a stock piece, not a huge deal.

Regards,
Stan

 

[ChrisS]

Skip--

What did that strut look like when you last hauled it, and if it was good, what caused its demise? Is your marina "hot"?

 

[skipper007]

Prepurchase photo

In replacing the engine we had a floating bond for some time. I bought a zinc guppy that went overboard, but the strut is (always) electrically isolated.

The prepurchase photo (Nov 2007) is shown below. Minkowitz noted some RED and recommended the zinc - which we attached.

I'm not sure about the stray currents in Marina Village, but the zincs were put on in Jan 08 and haven't been changed to date. So at a minimum we didn't eat too much, but I did add the guppy which isn't badly eaten either.

I expect we may have injured the strut and cutlass during our engine replacement. Although I hung the shaft inside the engine room it may have busted the set screw and that may have caused some of the damage.

I hope our thru-hulls are clean......Ohhhh what a boat.....

Skip

 

[David Westcott]

just did it on my Ericson 34

The strut was rotted from past zinc neglect. Fell apart in trying to change the cutlass bearing. Used Nelson Marine in Alameda-not a good experience. I would recommend Bay Marine instead.

The strut is embedded in the fiberglass on the 34 and bolts come down from inside. So fuel tank had to be removed and reinstalled-19 hours. They were able to use a standard replacement strut but that was still about $500 for the part.

 

[skipper007]

What were they thinking?

I guess no one ever expected to own an Ericson beyond the life of the strut.
19 hours (thanks David for the input) - OUCH there must be a lot of fiberglass work involved. ADD A ZINC TO YOUR STRUT NOW!!

BTW, In a PM, Guy voted Bay Marine as well. I just don't know how I'll get the boat up to Richmond from Alameda with no Iron Jib, unless we get a southerly breeze for reaching up the estuary.

Thanks to all,
Skip

 

[ChrisS]

Boatyard experiences

Skip, I don't mean to hijack your thread--I have a feeling I'll have to replace my boat's strut if I keep it long enough--but in this thread people have shared comments about boatyards, projects, and customer satisfaction. Maybe we could start region specific sub-forums where people could give feedback on which boatyard they used for a specific project, how it went, etc. I have used three different yards in the SF region, and while I would use one for project X, I would only use the other for project Y, etc, and it may get more business for a yard that knows how to fix a specific problem. Just a thought.

 

[frick]

I think I broke my strut

Yesterday, while sailing solo in a big blow, my job furler had a major over ride. I could not roll it up.
So I turned on the engine, locked the tiller and went forward to drop the genny.
In the flogging of a 24 knots of wind. The port jib sheet figure eight stopper knot shook out and it sounds up on the prop.
What a rookie mistake for a sailor of 53 years.

I was able to unwind a bunch of the sheet, until I hit a cut in the line.
I could limp back to port at 2 knots.
I went for a swim when I was back in my slip and quickly removed the rest of the rope.
It was very difficult to see under the boat, but it felt like my strut was loose. Crap.

I share more when I get my boat pulled this week.

1971 Ericson 29

Rick

 

[Leslie Newman]

I've owned several old sailboats and never had the strut eaten away such as yours. My 1986 CAL strut looked like new when I sold it in 2017. Makes me wonder if putting that zinc on the strut was a good idea. Or, possibly the electrical contact between strut and zinc was not good. Both zincs were not eaten away, making me suspect poor contact to the dissimilar metal. But I am no expert.

 

[Christian Williams]

Very complete five-Part blog on Strut replacement starts here:

http://www.ericsonyachts.org/infoexchange/entry.php?471-1984-E30-Strut-Replacement-Part-1

 

[Leslie Newman]

If your boats are tied to shore power all the time you may also want to look into adding a galvanic isolator. I added a Yandina GI-50N to my boat, but I normally leave it unhooked from shore power. Figured might as well have the protection for when it is connected. Very easy to install.

I decided on the Yandina unit and I contacted Yandina about the GI-50N. There response below....

So long as it is used as intended it has fail safe capability. They are not just "type-tested", EVERY one we make goes through the 130% ABYC fail safe rating test until the temperature stabilizes. However we have been selling them for 18 years with over 50,000 in the field all with UNCONDITIONAL warranty. To date we've not had a single return under warranty.

Regards,

Ann-Marie Foster,
tech@yandina.com

 

[frick]

Note the Rosie color

If your boats are tied to shore power all the time you may also want to look into adding a galvanic isolator. I added a Yandina GI-50N to my boat, but I normally leave it unhooked from shore power. Figured might as well have the protection for when it is connected. Very easy to install.

I decided on the Yandina unit and I contacted Yandina about the GI-50N. There response below....

So long as it is used as intended it has fail safe capability. They are not just "type-tested", EVERY one we make goes through the 130% ABYC fail safe rating test until the temperature stabilizes. However we have been selling them for 18 years with over 50,000 in the field all with UNCONDITIONAL warranty. To date we've not had a single return under warranty.

Regards,

Ann-Marie Foster,
tech@yandina.com

Interesting to note my 1971 e29 has no grounding or bonded bronze on the boat.
I do have a 15 amp battery charger which has not been plugged in all year.
There is a Hunter 50 next to me that is always plugged in.

My 12 volt system is grounded to the yanmar. And I do have zinc's on my shaft.
The broken truth has ended my season two months Early.

 

[GrandpaSteve]

Wow. This is confusing. An isolated strut should have never suffered dezincification. But here we have apparent evidence of that. Last haul-out I took a hard look at the strut and did not see any evidence of a problem. I have been considering adding a zinc as a precautionary measure, but what if that is what caused the problem here for Skip?

Hmmm.

 

[Leslie Newman]

I rarely see a strut with zincs. I am not going to do it. I have had five old boats over the last 34 years, no strut issues and no zinc on strut. Always replaced shaft zinc before it was eaten away. Always made sure the shaft zinc had good contact. I would suspect boaters with strut issues had continuity problems. But I am no expert. Just go by the saying if it ain't broke don't fix it. Of course everyone needs to do what they think is best for their boat.

 

[Frank Langer]

Wow, the variety of experiences and replies is fascinating! I can understand that in a "hot" marina, or if prop shaft zincs aren't replaced, it would be understandable for the strut to experience electrolysis/corrosion. And in a normal marina with zincs on the prop shaft, the strut should be isolated by the cutless bearing and not require a zinc. So there should be a definitive scientific answer that under conditions a, b, c it will deteriorate, but under conditions e, f, g it will be fine without a strut zinc.
Can anyone provide such information?
Frank

 

[footrope]

Salt Water gets my vote

Wow, the variety of experiences and replies is fascinating! I can understand that in a "hot" marina, or if prop shaft zincs aren't replaced, it would be understandable for the strut to experience electrolysis/corrosion. And in a normal marina with zincs on the prop shaft, the strut should be isolated by the cutless bearing and not require a zinc. So there should be a definitive scientific answer that under conditions a, b, c it will deteriorate, but under conditions e, f, g it will be fine without a strut zinc.
Can anyone provide such information?
Frank

Here's a possible explanation for the deterioration of an "isolated" strut. Since salt water is a pretty good conductor of electricity, I'd say there is no mystery as to how a boat floating in salt water can have a strut immersed in a flow of electrons caused by - whatever. Since the electrons do flow, and their flow is directional from the source outward to another conductor, you can get electrons flowing past and striking your strut from any direction or several directions at once. The electrons might be going outward from, or in towards, your own shaft and prop and their zincs.

Like any conductor, salt water is not a perfect conductor and the water has resistance to the flow of electrons. That sets up a difference in the voltage between two places in salt water. Indeed, the strut isn't a perfect conductor and it has resistance to electron flow. The electrons flowing to the strut and the difference in voltage (electrical potential) can probably cause an otherwise "isolated" strut to lose or contribute it's own electrons from the zinc in the alloy, for instance.

Many variables, yes, but salt water is why a metal part in the water cannot truly be isolated from electricity that is introduced to the water.

So, if your boat is in salt water I think the potential is there to have problems with the strut, perhaps only after many years, regardless of how well you maintain your shaft and prop zincs. I can't explain why a non-zinc'd strut on a boat might be just fine for many, many years except that the deterioration may be very slow or that the nearby metal parts are much more susceptible. But the environment the boat lives in changes from location to location, marina to marina and when your nearby marina neighbors come and go.

 

[Frank Langer]

Ok, that makes sense to me. Thanks for that explanation!
Frank

 

[Christian Williams]

the environment the boat lives in changes

I'll say. As kids we used to swim near a shock dock in Barnegat Bay. The closer you came, the more powerful the tingle. It started 50 feet away and within five feet zapped your whole pre-adolescent body enough to take breath away. We competed to see who could stand it the longest.

We're all lucky to survive childhood, but looking back--yikes!

I can't imagine what that would do to underwater yacht metals.