Saturday, February 25, 2012

Renewing the bowsprit chainplates

Last summer, while sailing in the San Juan Islands, I noticed that the nuts and bolts holding the backing plates of the port and starboard bowsprit mounting bolts (the hinges) were rusted away. This winter during haul out, I removed the roller furling from the bowsprit, removed the bolts and then dropped the bowsprit to replace the screws and nuts with 5/16" 316 stainless nuts and bolts. I had to grind off the old bolts.  During the repair, the bowsprit was held up by a 2 x 4 in place of the bobstay, the 2 x 4's ends notched to fit the boat.  I coated the new mounting bolts and nuts with Ultra-Tefgel, and used nylon locking nuts.  They should be fine for many years..
 Here is a picture from the outside port side bowsprit mounting.



 Above is a picture of the rusted backing nuts. The bolts were surprisingly intact, but were replaced.



 Here is a picture of one side, with renewed nuts and bolts.


Also, the prop shaft packing and prop shaft packing box hose were getting old, and the hose clamps holding it all together were rusty. I pulled the prop shaft out , replaced the packing box hose with proper 5 ply Buck Algonquin packing box hose, and the hose clamps with AWAB 316 stainless hose clamps. I also replaced the packing itself with 3/16" Duramax Ultra-X graphite packing. I used 4 packing rings, each offset by 120 degrees. I hand tightened so that at least 4 threads were covered, and backed on the locking ring. I am waiting to use the engine some, to allow the rings to seat, before making final adjustments.   I also put new zincs on the shaft.

The Duramax Ultra-X is graphite based and cuts well, without fraying. I bought two different sizes as I didn't yet know the correct size to use.

 Here is the coupler, the stuffing box, and the new 316L Stainless AWAB clamps I used. Our boat has a flexible coupler between this coupler and the transmission, so aligning the engine is vastly simplified, the flexible coupler is very forgiving.



Here is a close up of the packing box hose. You must use at least 5 ply non-wire hose for this, or risk ripping the hose in use.


Here is a picture of the first ring of Duramax Ultra-X installed. Use at least 3 separate rings, offset by 120 degrees.


 
Here is a picture of the shaft installed. I can't find any pictures of the reinstalled stuffing box inside the boat, but I take some new ones and upload to this post later on.


During the haulout, I also sanded off the 2 year-old Unepoxy Plus bottom paint, and replaced it with 2 additional coats. The Unepoxy Plus has worked well to hold off barnacles here in Puget Sound, yet did allow some slime buildup to occur. I needed to have the boat bottom cleaned once, after a year in the water, and the zincs replaced at that time. But that isn't at all bad for a bottom paint, and I had no qualms about using it again.