Last week I epoxied a 3" outer diameter collar onto the existing 2.5" outer diameter rudder tube that was cut when the wheel was installed back in the 1980's. I gave it a few days to fully cure and then proceeded to install the rudder and work on aligning the new tube that will slide down and mate with the collar.
I had my wife down at the rudder and swing it back and forth while I checked that it swung in a nice tight circle. It didn't; something was off but it was really hard to tell because there wasn't any top bearing to keep the rudder post true. Ultimately, we were able to get it close enough where I was able to hold the top of the post in my hand (as a bearing) and have my wife swing the rudder from side to side with no play. I had to keep telling myself that 'It's Going to Be OK' as we were doing it. I was freaking out a bit because I thought I had made some major error and wasted time and money building a rudder that won't fit.
Once I was satisfied, I shot some Thixo into the new collar and onto old rudder tube where the new one would mate and set the tube with a little bracing to keep it in place. Early the next morning I came back and added 2 layers of 4 inch wide 9 ounce tape to the seam where the collar and the new tube mate. That evening I came back and made sure things had tacked up and added 3 more layers with the same 9 ounce tape. I considered using the thicker 1708 biaxial fabric but I suspect it would have been hard to get it to lay down flat on the curved tube without some sort of vacuum clamping. In any event, I don't think it's necessary because there won't be any forces exerted on that section of the tube and only needs to keep water out. All told, I laminated 7 layers of the 9 ounce tape onto the new rudder tube just to make sure it's not going anywhere.
The top of the tube where it goes through the deck is another story though. It will be subjected to some serious bearing forces and will need to be structurally tied into the entire cockpit and heavily reinforced. Today, I'll start finishing the area by glassing in the fiberglass plate around the rudder tube and cutting the last of my balsa core to fill in the gap in the sole.
No comments:
Post a Comment