Jim, a few years back, you described applying HDMW (or something, not good at remembering) to your rudder post to take up slack in the gudgeon. How did that work out? How is the plastic holding up? Thanks.
I'm sure this is all in the archives but I'll give it a go. My memory is about as good as yours. For a few years of sailing the rudder would occasionally clunk when pressure was shifted as we sailed or motored or even sat at anchor with a slightly chop. I checked everything and tightened what there was to tighten without finding a solution to the clunk. The rudder itself was new so it wasn't an internal problem. One Spring when I took the rudder down to change the cutlass bearing, I took a digital caliper to the shaft and the inside of the gudgeon opening. My numbers showed that the gudgeon opening was about 40 thousands of an inch larger then the shaft. It doesn't sound like much, but it was enough to produce an audible clunk when the rudder shifted. I looked at three options: have a new gudgeon moulded ($$$$$), Have the gudgeon opening filled with bronze and machined back to proper specs ($$$), and filling the gap with some kind of shim material ($). Of course I decided to go with the ($) solution. On one of the online hardware outlets (I don't remember which) I found the HDMW, high density molecular sheets in various thicknesses with sticky back. If I can remember the numbers, I think I needed about .020 in thickness to fill the gap. When the rudder went back in with the new bearing in place the shim stock was added to the shaft at the gudgeon. No more clunk. It's been two seasons so far and there doesn't appear to be much wear on the shims. I will try to dig into my records to find where I ordered the stuff from. The posted photo shows the shim with a wood plug the proper diameter of the shaft.
thanks. I knew what you did. I was interested in knowing if the plastic withstood the friction or if you have had to replace it fairly regularly. I thought it was more years ago. I have a new rudder now and am replacing the delrin bearings. I also have just a little play in the post/gudgeon interface. Unfortunately it is different on the top and bottom of the gudgeon. I can only use a .022 sheet of HDMW. I think you had to use nearly twice that thickness, as I recall, Got the HDMW from McMaster Carr. The store for all seasons and reasons. Stay safe and healthy. Sailing may be the safest place to be right now,.
You are correct! McMaster Carr is where I ordered the HDMW. When the gudgeon was measured I was concerned that the wear on the opening was even all around. Thankfully it was and the shim idea was able to function. As I said, the wear on the HDMW appears to be minimum to this point. I am keeping an eye on it and am listening for any more clunks.
With this virus thing keeping us mostly cooped up in the house, we are upset that the boat is up on land until May. If it was in the water and ready for cruising it would be the perfect place to quarantine ourselves for a few weeks or more. As it is Bonnie has me working through her honey do list around the house.
I used the same stuff for the gudgeon washers. It was called UHMW for “Ultra High Molecular Weight” Polyethylene. There is also “HDPE” or “High Density PolyEthylene”, which isn’t quite as tough as UHMW.
The gudgeon on Dana is now 43 years old. If the UHMW outlasts the bronze, then I will never again expect to hear the "clunk". I'm very happy that I didn't have to resort to either of the big dollar fixes.