J/42 Rudder Stock Questions

[Albert Bossar]

Hi all, so after the previous thread on Jefa bearing failure, I of course went down to do some inspecting and some boat yoga in the hidden uncomfortable places! We did new lower + upper Jefa bearings last March. As far as the bearings things look solid. We did have some rust though on the outer stainless steel collar at the top, which was a bit unexpected and perhaps concerning. As I was rudder stock inspecting a friend who has done much work for us on our J/42, asked me some questions I did not know the answers too. We were looking for potential galvanic corrosion around the rudder per the Jefa thread that Chris sent around. So I have put those below hoping the wisdom of the group may know the answers or experiences or advice: 

#1. The mid section of the rudder stock for us is open fiberglass: Is that the same for others and if so why is the rudder shaft mid-section exposed fiberglass? 

Fiberglass is not water proof. Is this the same for others? From the few photos in the Group threads I could find, my rudder seems similar to others, but wanted to confirm and have folks applied an epoxy barrier coat to the exposed fiberglass if so? 

#2. Does the Stainless Steal tube extend the full length through the shaft? 

If the shaft extends up through that area, water incursion could lead to hidden corrosion of the shaft. And I'd want to get ahead of that for sure. I don’t have any pitting or corrosion on the shaft. And in all previous surveys no moisture in the rudder. The surveyors have all said our rudder and stock were very solid. So I had always felt confident in the stock being solid, but obviously would want to get ahead of anything.

#3. I am trying to determine if my "discoloration" of the mid section is just normal or may suggest some water incursion into the exposed fiberglass area, is this similar to others? 

A moisture meter would confirm it, but I don't have a moisture meter readily available. All previous surveys have never opined on this. The main portion of the rudder always test negative for moisture and the audible hammer tapping test sounds rock solid.

#4. has anyone grounded their rudder to prevent the possibility of galvanic corrosion? 

Mine is not currently and I didn't feel the need but possibly so?

photos attached are of the rudder stock out of the boat last march for bearing replacement. And then a couple images of now.

regards,

Bert

J/42 Allegiant

[Dennis Boyd]

Hi all,    while I was an engineer all my professional career,   I don't offer myself as an expert in corrision engineering. 

Bert has offered a lot of detailed questions.   

here is my take.    My rudder, while not dropped by me has had the rudder bearing replaced with a JEFA.   But it is getting long in the tooth.  I hope it hangs in there a few more years.    From what I can see, my rudder looks just like Bert's.

I can see no corrision, and we are carefull not to get bottom paint up in that small exposed area.   In fact, I  really cannot see any shaft from outside/below.

If I read the JEFA post,  they suggest two approaches.  Bond the rudder shaft with the "red wire" or isolate it.   They promoto isolating and they selling isolating bearing and connects to achieve this.   

If I read Bert's question, correctly,  i think he is asking if anyone has bonded there rudders?   I. E . added the "red wire" as shown in the JEFA post.   I have not. 

However, correct me if I have this wrong, but all my autopilot, helm rudder clamps are around the fiberglass bit of the rudder,  so if the f/g layup on the SS shaft is an effective insulator, then there is no need to bond, and the vessels have been built with isolation,  the JEFA prefer method?

I guess one could pull out a volt meter and run the JEFA test.     Also I guess I see no added benefit from attempting to seal this.  Might trap moisture,  and i would consider discoloration as just age. 

looking forward to what others think. 

Dennis,

[Chris]

Hi Albert,

I don't see the photos of the rudder post now, I don't think - or if one or more of the three attached are current, they look pretty good!

On your questions:

1 - I believe all of our rudders have a fiberglass shaft, except for anyone who's replaced it with a carbon fibre shaft. Certainly both of my rudders (I have the original that came with the boat and a redesigned deeper one which is probably the same as what most/all of the J/42's have - mine's a J/44). Sweet Ruca's video on changing their rudder bearings show the same design for their J/46 also.

2 - The stainless tube is just what you see - it's there for the bearings to run on.

3 - I will attach some photos of mine, but yours just looks like dusty old unfinished fiberglass, nothing I'd be concerned with.

4 - I haven't grounded mine since I believe it is isolated. The only way that I can see that one of our fiberglass rudders could stop being isolated would be for the quadrant or autopilot tiller arm to touch the top of the stainless sleeve. On mine that doesn't happen, so I haven't worried about it.

If your bearings are holding up then likely all is well - that's certainly how I feel about mine. I'm interested to know more about the problems Mike Arntz has had with his, and hope that his troubles are an isolated (bad choice of words?) case.

Thanks,

Chris

[Mike Arntz]

We were able to stabilize the rudder shaft using hard shims and air shims that we had on board, then got towed back to our marina. I’ll be hauling the boat in the next few weeks for a detailed inspection and I will update everyone with what I learn.

Mike Arntz

Bolero J/42 #16

Sent from my iPhone

On Apr 11, 2026, at 10:23 AM, Chris <j44s...@gmail.com> wrote:

Hi Albert,

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[Dennis Boyd]

All, 

interesting topic.    Just for my own knowledge.    Are we saying the the rudder shaft has a fiberglass middle and SS shaft at ends?   Or is it a SS shaft, with a fiberglass "fat" section in the middle?    

I am unclear.

Dennis

[Larry Romano]

It’s a fiberglass rudder shaft with stainless steel sleeves over the fiberglass in the bearing area. It gives the bearing a surface to ride on.

On Apr 14, 2026, at 11:36 AM, Dennis Boyd <dennis....@gmail.com> wrote:

All, 

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/aeaea23b-8555-4d76-a7b9-1a0f502cecd0n%40googlegroups.com.

[Mike Arntz]

My understanding is that our rudder shaft is carbon wrapped in fiberglass.  The stainless sleeves fit over the fiberglass as Larry described above.

To view this discussion visit https://groups.google.com/d/msgid/j4x-owners-group/C430F46B-659A-4A19-A65E-0864A979451C%40gmail.com.

[Ed Sitver]

My understanding is that the rudder stock is solid fiberglass (G10?), but I can’t recall how I came to that conclusion. But, for sure, the stainless at the top and bottom are just sleeves over the stock.  Photo attached of my J/42 rudder stock going back into the boat on a rainy morning. The area of blue tape at the bottom is the stainless sleeve for the bearing to ride on (tape was protecting from epoxy, and this is just before I removed it for install). The course for my lower bearing was just G10 (or G10-like) when the rudder came out -- no stainless! I epoxied on a stainless sleeve machined by Jefa (shout out to Jay Pasco-Anderson for his support).

Ed