Reinstalling a rudder shoe? (peening copper rods)

[hebert01]

Over the winter I removed the bronze rudder shoe on my Ensign so that I could remove the rudder for repairs. The rudder shoe holds the base of the rudder shaft, and is attached to the hull by means of copper rods that run through the hull, and then are peened on the ends to hold the shoe tight to the hull.

With a fresh supply of copper rod at the ready, I've started the reinstallation and am feeling like a fool. How does one peen both sides of the same rod without pushing it back and forth through the hull?

I've tried the two sledge hammer technique, with me under the keel attempting to tap both sides of the same rod at the same time. It evidently requires way too much dexterity and timing, as I can't effectively tap what I can't see. If the strike isn't square and timed exactly, then the fastening rod moves clear through the hole and the other hammer strikes only the shoe / hull. This can't be the method used originally.

I also tried leaving quite a bit of overhang and tapping one side down perpendicular to the path of the rod through the hull (to lock the rod), but as soon as I start tapping the other side in the same locking manner, it loosens and begins to push out the other side. I tried clamping a block onto one side to provide a resistance to the hammer strikes from the other side, but even that bounces off the hull slightly when struck and doesn't provide a solid base that allows the rod end to distort.

So with that, any ideas on the proper technique for peening both ends of a rod?

[feetup]

Ideally, the job is done with two people, the riveter and the bucker. In the old days of riveted hulls (and bridges and even boilers) the red hot rivet was thrown up from the forge with a pair of tongs and caught in something that looked like a garbage can lid. Then it was placed through the hole and the bucker held the "Buck" (who'da thought?) against the rivet while the riveter on the other side peened the end over with an air hammer. You can simulate the process, without the heat. If you must do it alone, only one hammer strikes the rivet, and the other just backs it up. The bucking hammer, the one that doesn't strike should ideally be somewhat heavier than the striking hammer, and should be held either by the head, or choked up very close to the head. Once you have developed a good bit of head on one side, switch sides and peen the other side. You don't need to beat the daylights out of it or you will only cause it to bend in the middle. Less severe blows, working your way around the corner circumference will upset the head much better. Be purposful though since the copper will work harden and become immune to the blows. It is common to upset one head in a vise and only upset the other when it is through the hole and ready.
One more thing, if the copper is not annealed you will have a much harder time getting it to upset properly. If you have the tools you can anneal the copper yourself. It works just the other way around to steel, heat it to dull red (indoors or in full shadow) and quench it in fresh water. It will go very soft and easy to work, but will harden up as you work it.

Feetup

[CharlieJ]

I have the same setup on my Meridian. What I did was peen one end first, outside the rudder shoe. Then I inserted it, put a heavy weight on the side I peened ( I used a wheel weight off a tractor- about 25-30 pounds of cast iron) and used a small ballpeen hammer to peen the other end. Light taps and many of them seemed to work best. Then I smoothed the ends flush

[hebert01]

Thanks for the tips, guys. I'll give it a shot!

[hebert01]

Just following up...I managed to reattach the rudder shoe today, and used feetup's suggestion for annealing the copper prior to peening. I think that did the trick, as the copper became much more malleable after treatment. I had a friend hold sledge on the other side while I tapped, and then vice versa.

Thanks again to all for the advice!