Re: Rudder Packing—again
toggle quoted messageShow quoted text
I don't think that you would need to extend the shaft tube very far to accomodate one additional packing ring. Fiberglass/epoxy would be far stronger than the JB weld, especially if you prepared the surfaces of the original fiberglass structure to bond your extension to. You could screw your extension tube "mold" into the existing threads after preparing all surfaces. Wax your mold well with a mold release wax and make the wax thick at the bottom to insure no epoxy can drool down the tube. Then mix up a thickened epoxy, using collodial silica, maybe adding some finely milled fiberglass. Coat to fill the threads in your mold filling all voids, then wrap many layers of 10 ounce cloth cleanly cut so that you don't have a mess. Build the thickness you want for the tube extension then using more thickend epoxy fair the new tube into the original fiberglass structure and fiberglass the extension tube to the original structure lapping perhaps 2" onto the original structure. 10 layers would probably do it. This way your extension tube is not relying on just a bond to the top of the original structure, you will have a significant and strong attachment. The glass fiber wrapped around the mold will form a strong tube that can withstand considerable tension from tightening the nut and should not crack on you. You may need 50 more more layers and if needed do this layup in stages, curing the epoxy and preparing the surface. I often use the West 105 Epoxy resin for these types of jobs but a harder/stronger resin might create stronger threads. Regardless of the epoxy resin, I would do a post cure per the epoxy resin manufacturers recommendation to raise the glass transition temperature and improve the hardness and strength at room temperature. On the other hand, if your current solution with the Dripless packing has done the trick, maybe doing nothing is an even better solution!
Recovering in Marmaris Turkey aboard SV Sueno
From: Bill Kinney <cruisingconsulting@...>
Sent: Tue, Dec 28, 2021 12:20 am
Subject: Re: [AmelYachtOwners] Rudder Packing—again
Francoise at Amel in Martinique has a great solution. He has designed an extension of the shaft tube which is epoxied and screwed in place. I now can insert 5 -3/8's packing strips and 6 if I press down hard. I use a 2" sch. 80 PVC pipe to set the packing and don't drive them in too forcefully. I use the gland nut to apply the pressure to stop all leaks. 10m months, lots of bashing and no leaks.
Extending the shaft tube was going to be my next step if the Dripless packing didn’t work. My plan was to cast an extension in place using JB Weld, or something similar.
I’d love to see a picture of what yours looks like, because I can’t see how I could extend my tube that far (2.5 to 3 cm?) without making major changes in the alignment of the various parts of the steering gear that seem like they would be complex to sort out.
Fort Lauderdale, FL