Stuffing Tubes and Rudder Posts

This weekend I took some time and installed Nassau's stuffing tubes and rudder posts. The trick is to get everything installed with everything lined up. This is the second time I have used this technique and it works well. 

Stuffing Tube? Rudder Post?

Maybe I made these terms up... maybe I heard them somewhere... I don't know. To avoid an confusion I better define what I am talking about installing.

A stuffing tube is a tube through the hull which a propeller shaft assembly can be placed through without water leaking around it. When I say propeller shaft assembly in this context I mean a stationary tube which houses bearings, grease and the spinning propeller shaft. I will describe how to make these in another post. The stuffing tubes need to be long enough so that both ends of the tube clear the hull (plus some epoxy putty) The stuffing tubes in Nassau are 1/4" brass tubing. I will explain why when I describe how to make the propeller shaft assemblies. The important thing is that the propeller shaft assembly will fit through a 1/4" brass tube without water leaking around it.

A rudder post is a stationary post which the shaft to the rudder turns in. So long as the top of the rudder post is higher than water level it is not important if water can get between the rudder post and the rudder itself (as long as they can not corrode together). Nassau's rudder posts are made of 1/4" plastic.

The Jig

The "secret" to getting everything laid our correctly is to make a jig which holds your propeller shafts and rudder posts in their correct positions relative to each other. The jig also needs to be able to be placed next to the hull in such a way that the center shaft, while in the jig, is precisely where it should be in the hull.

In my case Nassau's propeller shafts run level and parallel to each other so the jig is fairly simple. The best thing about this is that I could use the table to position the jig.

I then used the jig to mark approximately where the holes need to be drilled in the hull.

Unfortunately I did not snap a picture of the holes. The trick is to make the holes larger than needed. How much larger? Large enough so that I could correct errors in the placement of the hole. The marking is not perfect and drill bits tend to wander. However, I made certain that when pressed over the propeller shafts in the jig the brass for the stuffing tubes would pass through the holes without contacting any side.

Install Stuffing Tubes

The first stuffing tube I installed was the one for the center shaft. I took great care to make certain that this shaft was absolutely strait. For a reference I used a piece of aluminum angle laid down the center of the ship. I then placed some extra brass on the end of the propeller shaft to make it as long as possible. I lined up the shaft (and extension) with the aluminum angle.

Once I had the center stuffing tube installed the jig helped insure the other propeller shafts are aligned correctly.

I used LocTite Epoxy Putty to install the stuffing tubes. The trick to installing them is to not worry about getting the hole completely filled in all at once. The putty sets up fast. For the first application of the putty I only worried about immobilizing the stuffing tube in its correct location. Once the stuffing tube was immobilized I removed the jig and completely filled in the hole on both sides of the hull. I really plaster the putty on as it easily sands down to the shape later.

The other stuffing tubes went it very quickly once the center one was in place (to hold the jig).

Install Rudder Posts

I can now use the stuffing tubes and jig to precisely locate the holes for the rudder posts. Once again, it I made certain the holes were over-sized. This will required that I drill small holes with the jig in place but then remove the jig to re-drill the holes with a wider bit.

Once the over-sized holes were drilled I reassembled the jig - this time placing the plastic for the rudder posts in the jig. I installed the spacer at the top of the posts - mostly to ensure they were parallel to each other. Once everything was lined up I used the epoxy putty to glue everything together (and fill the holes)

There is a reason I used plastic for the rudder posts - this technique requires that the rudder post extend far beyond the bottom of the ship during installation. The following picture shows this pretty clearly.

Unlike the stuffing tubes and propeller shafts it is not critical that the seal between the rudder post and the rudder be watertight. The trick is that you make certain the top of the rudder post is above the water line. In the above picture you can see a pencil line representing the water line. I am paranoid so when I drilled out the rudder posts I made certain the hole was small enough to provide a watertight seal around the rudder. However, my Battleship Lion did not have this precaution and the rudder has never leaked. Actually the propellers are a much bigger problem in that ship...

The last things to do were to cut the rudder posts down and sand away an excess putty.