Well, we got off to a strong start with the rudder 'repair'. First stroke of inspiration was to use a commonly available stud-finder with metal mode to non-intrusively map out the inner structure of the rudder skeleton. It turned out that Pisces' rudder had a nice big wing-shaped section of stainless steel attached to the rudder shaft. We confirmed this with one test hole, and also confirmed that the foam was nice and dry inside the rudder. Awesome, a little epoxy and some fiberglass tape and everything should be as good as new.

So, we set up some makeshift saw horses, got the epoxy ready, and...crap...noticed that there was good bit of corrosion on the lower end of the rudder shaft. This is a potentially huge problem, as it can progress quickly (or slowly) and lead to significant weakening of the rudder shaft...which is bad.

Here's a list right now of our thought process. It's helpful for me to just get it written down.

Technical details:
- Shaft is 1 1/2" Nominal Sched 80 304 stainless (wall thickness ~.2")
- Surface corrosion (estimate less than 10% penetration) covers a several square inch area, primarily low on the shaft.
- Deeper corrosion/pitting (estimate less than 25% penetration) in groups, some in the area around where the shaft enters the fiberglass body of the rudder and some more randomly distributed on the exposed shaft.

Thoughts on possible causes:
- Not galvanic corrosion, as this piece is in contact with no other metals.
- I don't think it's stray current corrosion, as I haven't seen any other undue corrosion/problems with paint or anodes.
- Could have been caused during the time period when Pisces sat in Oxnard seeing very little use. At this point the shaft probably sat in one particular orientation for long periods of time without use/water flow.
- Could have been due to improper polishing/prep of the shaft by builder.

Thoughts on Outcome:
Really everything falls in one of two categories, fix or replace. Fixing is very tempting as the rudder is extremely well built in every other way, and fixing would also be the simplest and cheapest thing to do. On the other hand, if the shaft breaks we are in some real serious trouble. Here are some random thoughts/brainstorm ideas on the fix/replace options:

Fix
- As shaft is hollow, could insert solid stainless rod inside that would fit snugly and extend up past the end of the area affected by corrosion. This would perhaps give a bit of extra strength in addition to the shaft wall.
- Looking into epoxy/ceramic materials such as Belzona. These apparently are used by the Navy and merchant ships to resurface/repair shafts as well as to inhibit future corrosion. This is probably also pretty expensive for what it is.
- We still need to get a lower gudgeon/rudder shoe fitting made. It's possible that we could somehow find an option that kills two birds with one piece of bronze. For instance, we could potentially move to a more traditional gudgeon/pintle set by strapping the pintle onto the rudder, thereby removing load from that section of the shaft. Or, we could cut off most/all of the corroded shaft, insert a pin up into the remaining good shaft, and use this as the pintle.
- Could do some combination of the above, most likely would be Belzona or similar coating combined with internal shaft for extra strength.
- Seems also possible to me that since we will have a new gudgeon with the ability to add a sacrificial zinc, that it's not unreasonable to think that the corrosion would be significantly slowed/stopped from here on forward. (or am I just engaging in some seriously wishful thinking?)

Replace
- We got a couple quotes from rudder manufacturers, and it's not outlandishly expensive to get a new one built...I mean don't get me wrong, it's not cheap, but it wouldn't break the bank right now. We don't have the time to do it ourselves, at this point it's all we can do to get up in the morning, go to work, etc. We want to get through with what we have to do, and then get back out cruising.
- Plus of a new rudder is that it's new, no corrosion.
- One downside is that I don't think a new rudder would be built as well overall, for instance the metal skeleton inside would be substantially smaller, and the glass would be much thinner.
- Also, a bit of a logistical problem as we have to ship the thing across the country, then have them ship the other one back to somewhere depending on how long it takes (Tucson?). Also, although the manufacturers seemed to think they could get it done quickly, this is definitely the option most likely to cause delays in our cruising plans.
- If we are going to go through with the trouble of doing a whole rebuild, I'd like to take the opportunity to significantly improve some pieces of the rudder. For example having a solid shaft would open up some superior tiller attachment options, etc. Problem is I get quickly bogged down in trying to deal with these new options, and suddenly the job is even bigger than 'just' getting a new rudder built.


Alright, that's my current pain. Take a look at some photos (click to enlarge), and tell me what I should do :)