1969 Chris Craft Roamer 46 Refit: Rudders

Way back in the 1980s, the previous owner had the Roamer towed from Washington DC to Colton’s Point Marina in southern Maryland. One of the guys who did the tow said it was particularly difficult because the rudders were locked in position. The Roamer wanted to turn to the left all the way down south. When we got the boat, I found the steering gear broken and the rudders absolutely unwilling to move. We ended up cutting them out and having new ones made.

The key phrase here is “dissimilar metals”

The original plain steel rudders were frozen in time…circa 1985, I do believe.

The rudder view from the inside

Here we have the aluminum Schedule 40 pipe for a rudder shaft log, through which runs the rudder shaft itself. Threaded onto the top of the aluminum pipe is a standard bronze packing gland nut. Three different metals (more, actually, because they’re all alloys) in a water environment. Add to that the fact that the boat didn’t move for years before it was finally hauled and you have a seriously locked up rudder shaft. I was unable to remove the gland nut even with a 4′ pipe wrench. Penetrating oil didn’t help. Heat did nothing.

A 12 ton ram chained to the rudder achieved…nothing but an interesting photo opportunity

Again, heat did nothing. These rudders were simply not coming out.

Enter the sawzall. And out came the rudders! 😉

Note that there is a grease nipple on the log. From the look of it, the logs hadn’t gotten a maintenance shot of grease since it left the factory in 1969.

With the rudders out, I sent one off to a fabrication shop for replication

What came back from the fabricator was a nice set of brand new stainless rudders and hydraulic steering gear

The tie rod is actually straight though it looks curved in the pic

The view from the inside

Rather than threading a bronze gland onto the aluminum, we’re using a shaft log hose and spud approach that will isolate the aluminum from the bronze. The Devoe epoxy coating will also help isolate the aluminum from the carbon in the hose. Most important, though, is that we will actually use the boat, so the rudders will be less likely to lock up solid.

The new rudders from the outside

We took a different approach with these than Chris Craft did. The rudders don’t come into direct contact with the aluminum log. Instead, there is a delrin sleeve pressed into the log and the stainless rudder shaft turns inside that. For all intents and purposes, the stainless is isolated from the aluminum, at least in the wet part of the system

In retrospect, plain steel rudders in an aluminum log with a log hose and spud might be a better approach than the delrin sleeve. With a shot of grease into the logs, there’s no reason why the original Chris Craft approach wouldn’t work well. In fact, plain steel is less aggressive against aluminum in a wet environment than stainless steel. Check your galvanic series if you don’t believe me. 😉

My concern with the delrin sleeve is that if aluminum oxide forms between the log and the sleeve, it will compress the sleeve and squeeze the shaft–perhaps causing it to bind. While the same thing could happen in the original configuration, if you drive the boat and turn the rudders, the Al2O3 ought to turn to paste and be flushed out when you go through the water. If the Al2O3 is stuck behind the delrin, which doesn’t rotate, then I don’t see how it will be flushed out.

In any case, it’s too late now to change things based on theory alone. Maybe the delrin will work flawlessly. Time will tell.

Next up for our 1969 Chris Craft Roamer Refit: Fairing the Topsides.

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5 comments on “1969 Chris Craft Roamer 46 Refit: Rudders

  1. bill thomas says:

    Looks like you made the rudders in line with the tiller arms. That is wrong and it’s not how your boat was built.

    • 1969roamer46 says:

      Thanks for the input, Bill. Actually, my boat was built with mechanical steering and dissimilar metal corrosion rendered the steering system completely nonfunctional in no time. So, you’re absolutely right about the rudders not being of original design: they’re far better than original. As to them being “wrong,” you’re welcome to your opinion. I might even agree with you if you could elaborate a bit and explain what’s wrong about them.
      Cheers

      • bill thomas says:

        Yes, I understand about the dissimilar metals and all that, and everything that you did too. But – there is geometry to rudders and steering. Tiller arms are not in line with the rudders, but should be both angled inward from the rudders about 10 degrees. Rudders are only parallel when the boat is going straight ahead. On a turn, the inboard rudder is at more of an angle than the outboard. This is because when in a turn, the inboard rudder is at a shorter distance to the center of the turning radius. This is like automobile steering, the inside wheel turns sharper. In automotive terms, this is called Ackerman Principle. On a boat, this keeps a good flow across the rudders.

        • 1969roamer46 says:

          Ah! So, you’re talking about the lack of rudder toe-in (or out) rather than tiller arm orientation to the rudder blade. Gotcha. A few others mentioned it via email, so I plan to toe the rudders in before we launch. Word has it toe-in is preferred to toe-out, and 2-3 degrees is adequate. Without it, they say that rudder shudder when dead ahead at higher speeds is a problem.
          Thanks for bringing it up in the comments section. It’s good to have notes like this.
          Cheers,
          Q

  2. Bill Tozer says:

    Q – shakes head… but I gotta admit this is one hell of a project!

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