Prop Shaft Strut replacement

Hello - looking for leads on getting a replacement prop shaft strut. Pulled it off to re-bed while replacing the shaft seal, and found that it had completely cracked off at one corner. not enough left to repair.

3/4" shaft.

Tried the Prop Dr in Key West that was referenced in an old post, but they are no longer in business.

any help appreciated, would consider used as well.

There is a for sale thread of a decommissioned J/30 in the classifieds. Good first bet.

What do you mean "cracked off at one corner"? Cracked a corner of the base off where the mounting bolt is? If you can't replace, you could probably glass over it to secure it.

The Prop Doctor in Key West is still in business. I talked to him today. Try calling him @ 305 292 0012 on Tuesday. You might want to consider having the shaft and cutlas bearing checked for wear when repalcing the strut.

Thank you , I will give him a call. I had a number from the old post that was for a different company.

I am getting the shaft checked for balance, and replacing the cutlass bearing and shaft seal. Hopefully that will be it for this part of the boat for a couple years.

I emailed the parts boat, but no reply. One of the corners broke off, meaning the entire corner and bolt hole. I found a welder today you thought it could be repaired. But even he suggested a replacement as the bronze is deteriorated and flaking and crumbling in several areas.

Thanks for the reply!

over a year ago Horatio, our local fiberglass guy and TPI factory employee back in the 80s, recommended that he fiberglass the strut on 526 completely in ... for nearly 30 years this had been a problem for me and required fairing each year. he claimed it was the only final solution ...

this is photo of it one year later ... not showing any signs of problems. Somewhere I think there is a photo of it unpainted on this site from last year.

I faired over mine this year with a strong epoxy mixture. But if it goes back to leaking, I will glass right over next time. I noticed one bolt appeared to be stripped, but after tightening all three and epoxy fairing, it feels solid. Of course, less vibration now too, and no leaking anymore (fingers crossed).

Where were you seeing leakage, into the boat itself? Hull core??

Never had any problems with mine (maybe I should be worrying about this too

-dan

As Vic had mentioned to me before, it is a common thing for the prop strut bolts to leak. This does not get into the core because of the solid mold for the strut. After running the boat, My bilge would fill up every 12-24 hours until the algae growth would cover the bolts again and slow the leak. I could not find where the water was coming from anywhere as it was not the stuffing box and somewhere under the cabin liner and only happened after running the engine. After mentioning it here, Vic said it was the strut bolts. After fairing it two weeks ago, no leaks after running the engine.

I guess owning two J/30s makes him twice as smart. Thanks Vic!

Problem now is that I forget half of what I learned ... so am constantly learning stuff I learned before ...

quote of the year: "I knew that!"

So OK we add another season to the original repair of fiberglassing the strut into the bottom ... no sign of any change.

Just as you had trouble with Vic, mine started leaking again about a month after fairing. I think the vibration cracked the fairing.

I plan to take some pictures and do up some drawings as I'd really like to know the inner guts of how that strut is mounted to the molded recess. The bolts are not visible on the inside, just a square piece of epoxy that the cabin liner abuts. I hope to put it on the hard and remount it but I'd like to know what I am going to find when I start grinding off the backing first.

Scott,

I noticed some cracks around mine when I had Red-Five on the hard last spring. I assumed the damage was from excessive vibration from my prop, which was not always unfolding. I had the yard touch-up the glass work around the strut and replaced the prop as part of the work that was done last year. She's back on the hard for hull paint right now and I checked out the strut on Tuesday. No further problems this year. Maybe the cracking is a symptom of excessive prop/shaft vibration? Have you checked shaft alignment? How's your prop?

Dom, Is the glass right over the base of the strut, or is your strut base completely exposed?

Debating a new Martec prop rather than sending mine in just to see if it can be rebuilt only to find out it isn't worth it. My prop really has trouble unfolding without a wild burst of reverse.

I put in quite a bit of effort aligning my engine last year so the shaft alignment should be good unless the shaft itself isn't true.

Scott,

It's pretty smooth right up to the strut but I'm not sure if it's glass or fairing compound.

There is a guide on the prop on the Martec site in terms of rebuild-ability. The wildcard is the electrolysis factor. How pink is the prop?

The difference in cost between a rebuild and a new prop is about $300. Just enough to make your think long and hard about getting a new one. Sending the prop down to them to find out cost more in yard storage than UPS charges. So it might be best to just order the new one so you don't have to pull the boat out, wait the 10-14 days or so for the whole process of shipping your old prop down, refurbishment and shipping back north.

The strut on my boat - Hull 25 is bent and needs to be replaced. Apparently the dimensions of the strut change depend on when the boat was built. Long shot request but does anyone know of any early version prop strut aviailably possibly from a boat that has been parted out?

Phil - Try contacting Ted on this link for a boat that was parted out.

You also may want to see if the existing strut could be used to make a mold for a new one to be cast. This place will do bronze castings.

Thanks Bill, I also sent an-mail to the guy in Chicago that parted out a boat that a few years ago.

for the archives:
photo of typical strut to bottom joint.
looks pretty much the same 3/4 or 1 inch shaft.

The install that Vic photographed doe not look like the normal fairing job I've seen on most J/30s. You can clearly see the outline of the strut and fasteners in that photo. On most every boat I've seen there is no evidence of any change in shape on the outer skin.

roger, roger ... that photo was picked up from the Mojo for sale site photos. not a vic photo.

Bill -- you are too close to the "racing" hulls ... the guys that cruise aren't obsessed with fairing the strut in every year. They just want a fun boat to sail.

Got the strut off of Chaos this week and found that the two forward bolts holding the strut were glassed over. Only the two stern bolts were accessible. I assume the forward bolts are held in place by nuts encased in fiberglass. The stern bolts are behind the engine bulkhead, while the forward bolts appear to be in front of the bulkhead.

Does anyone know if this is the way all of the boats were manufactured?

Rhapsody is the same.

I was going to replace the cutlass bearing yesterday and noticed that the strut is loose. My only problem is how to fix it.
On the outside the strut mount and bolts are faired over
On the inside the strut bolts are not visible. If I look in the cockpit locker there is absolutely no sign of the strut. When I look in the engine compartment, there is a rectangular piece (I think of wood) fiber glassed into the liner where I think the strut should be. Are the strut bolts under that peice?
Can I cut that out with a Dremmel and find the strut bolts under that?

when you say faired over ... do you find that this fairing cracks every year? On 526 and 505 my fiberglass guy ... also on the line at TPI 30 years ago, admitted that the engineering on that was marginal ... he then decided the only way to go was to actually fiberglass the outside of the hull over the strut base.

Yes you need to dig out access inside. Earlier in this thread, I have a photo of the outside fiberglass on 526.

The fairing has cracked around the strut. Probably due to the fact that the strut is loose and moves a bit

When I fixed Natural High, that square piece in the engine room was solid epoxy and the nut heads are embedded within it. I did dremel them out, filled the gaping holes with epoxy again, and then put in longer through bolts so the heads were accessible. The rear strut bolts are hiding just outside the aft most bulkhead (below the control panel). You need to put yourself inside the lazerette upside down to get at them!!

First I cut away the fiber glass that covered the outer surface of the strut. Then, I drilled a small (1/8") hole just in front of and one just behind the strut but in line with the bolts.
I measured the distance from the drill to the strut bolts. From inside, I measured back from the drill hole and took a small hole saw and drilled over the bolts. After breaking away the material, found the nuts and tightened the strut. I found the back bolts in a similar fashion but did not need to drill as the bolts were barely covered.
I replaced each of the bolts with longer ones, added lock washers and nylock nuts to insure that they would remain secure.
In the front, I built up a 5/8" damn 7" x 7" and filled it with additional epoxy. Then I took a 1/4" x 2" x 5" piece of stainless, drilled holes to align with the strut bolts and placed it on top of the epoxy base that I had built up.