Steering Loss Continued... Corrosion Q

[montenido]

Hi all, finally got down to the Sundance to take a look at the steering to see what failed last week. It turns out that one of the anchors for the cables that attach to the rudder shaft failed, apparently from corrosion. The Edson helm uses a cast aluminum wheel that mounts to the rudder post. The control cables wrap around this wheel and terminate in molded "lugs", which have holes drilled into them and which the cable ends thread into. One of these "lugs" broke off, leaving me with no steering. I spoke with someone at Edson and they were helpful. A new wheel will cost about $250, not too bad. I cannot remove the old one in one piece, so I am going to try to salvage it by installing SS eyebolts on either side of the lug. The threaded cable end will still be able to attach in the same spot. I am not too sure of durability, but it will be easy to monitor. If it doesn't work, I am only out about $8 in SS parts. That brings me to my big question, how do you free up corroded parts? The rudder shaft looks like SS and the rudder wheel is aluminum. 27 years later, the parts do not want to part with each other. Is there a good spray that frees up parts like this?

Thanks for any help on this.

montenido

[Rockter]

Mont...

Do you have a wee picture?

My own wheel is stainless to stainless, and 32 years on, it slides off easily but stainless and aluminium are notorious for quarrelling like this.

Releasing fluid will help, and you may have to use a little heat, and hammering. Don't roast the stainless too hot as it tends to lose its corrosion resistance if overheated with a flame.

[Gary1]

The product PB Blaster is about the best penetrating spray I've found, but, alas, it may or may not work on a s/s to aluminum bond.

I'll go along with a judicious amount of heat and a hammer. These might work, but have patience, and remember that aluminum has a low melting point. Much lower than s/s.

Finally, when you're reassembling everything, put it together using Loctite 242 (the blue stuff). I know this seems to defy reason, but putting a coat of Loctite on a s/s fitting that's going into aluminum somehow prevents the bonding process that normally takes place.

[sailingdog]

I don't think a penetrating oil is going to help much. You should probably use heat—either a heat gun or even boiling water might do the trick.

When you're reassembling it, don't use Loctite. Use TefGel or LanoCote. These are designed to prevent galvanic corrosion between dissimilar metals and are not adhesive in nature. Loctite is basically a cyanocrylate adhesive compound which is primarily designed to glue the two pieces together, making future separation more difficult than TefGel or LanoCote would. If it were a SS screw going into an aluminum piece, as you might be doing on your repair jury rig, Loctite would make sense, but not for two pieces that are supposed to be friction fit and then held in place by a set screw.

Even if your steering quadrant was stainless steel going on a stainless steel shaft, I'd recommend using TefGel or LanoCote, since Stainless Steel has a tendency to gall when two pieces are in contact.