Shimming rudder shaft

[Hayden Watson]

I think the Catalina repair is nuts.

On my Ericson 26-2, the rudder post/rudder tube is just as it is on my earlier Catalina 30-MK II: a stainless shaft that goes through a fiberglass tube without any special bearings on the top or bottom. Though I didn't need to shim the Catalina 30, I did do it on my Ericson 26 to reduce the play. I used stainless steel shim stock that I bought from McMaster-Carr. I shimmed it on the top (.005", where the rudder post comes into the cockpit and attaches to the tiller head) and bottom (.015", where the post exits the bottom of the boat). Realize that these are the only two surfaces on which the rudder post bears and so filling it the entire rudder tube with epoxy only creates unnecessary drag in the middle section of the tube--not to mention the fact that you can accidentally glue your rudder post so it won't turn! (I do know of just such a case.)

I think that you misunderstand what the epoxy / graphite repair is. It does not fill the gap full height. It only has about 2" of contact at the top and 2" at the bottom. You drill three holes (120º between each hole) that angles down into the rudder log about an inch down from the top and another three holes up into the bottom of the log about 1" from the bottom. You then inject about a tablespoon of the mix into each hole which makes six 2"ø pads of graphite impregnated epoxy at the top and bottom. You then "mold" the pads to match the regularities of the shaft by turning the rudder from lock to lock while it is not quite hard. Mine came out just a bit too tight due to the roughness of the turnings on the shaft of the RudderCraft rudder I installed but that was not due to the epoxy / graphite fix.

 

[Alan Gomes]

I think that you misunderstand what the epoxy / graphite repair is. It does not fill the gap full height. It only has about 2" of contact at the top and 2" at the bottom. You drill three holes (120º between each hole) that angles down into the rudder log about an inch down from the top and another three holes up into the bottom of the log about 1" from the bottom. You then inject about a tablespoon of the mix into each hole which makes six 2"ø pads of graphite impregnated epoxy at the top and bottom. You then "mold" the pads to match the regularities of the shaft by turning the rudder from lock to lock while it is not quite hard. Mine came out just a bit too tight due to the roughness of the turnings on the shaft of the RudderCraft rudder I installed but that was not due to the epoxy / graphite fix.

I think I did misunderstand it. I still wouldn't do it, however. I do know one person at least who had a heck of a time breaking his rudder post loose, but managed to do so without damaging his rudder tube. It was touch and go.

In any case, the stainless shims are a simple and effective fix.

 

[colemj]

Even if the graphite in contact with the stainless isn't an issue, I'd still drop the rudder to inspect the post before doing this. If there are pits or grooves in the shaft, it could really lock things up. It would also give one the chance to wax the shaft so that sticking is less of a problem.

I also have reservations on injecting epoxy into a bearing whose surface hasn't been cleaned and abraded first.

Mark

 

[Hayden Watson]

Even if the graphite in contact with the stainless isn't an issue, I'd still drop the rudder to inspect the post before doing this. If there are pits or grooves in the shaft, it could really lock things up. It would also give one the chance to wax the shaft so that sticking is less of a problem.

I also have reservations on injecting epoxy into a bearing whose surface hasn't been cleaned and abraded first.

Mark

Dropping the rudder is mandatory because you cannot drill the three injection holes top and bottom with the shaft in the log. Once the rudder is out, you clean and abrade the inside of the log with a sanding drum on a drill then clean with acetone or 90% Isopropyl alcohol. The shaft also needs to be coated with numerous coats of form release wax. All of this is covered in the West System repair manual.

 

[Project_Mayhem]

When using a feeler gauge to measure the gap, does the feeler need to be bent to make it fit and/or get an accurate measurement?

Dropping the rudder is mandatory because you cannot drill the three injection holes top and bottom with the shaft in the log. Once the rudder is out, you clean and abrade the inside of the log with a sanding drum on a drill then clean with acetone or 90% Isopropyl alcohol. The shaft also needs to be coated with numerous coats of form release wax. All of this is covered in the West System repair manual.

Thanks for the thorough explanation!

 

[Ward H]

When using a feeler gauge to measure the gap, does the feeler need to be bent to make it fit and/or get an accurate measurement?

The size feeler gauges I used were thin enough to bend slightly around the post.
From my notes, the gap at the top was .05 and the bottom was .03. I bought .015 and .012 SS shim stock from McMaster Carr. I used the .015 on the bottom and doubled the .012 for the top.