Thanks Rob, Because I have a Nonsuch 33, built by Wiggers, I have even more mysteries this first year of ownership. My boom does have similar ss/aluminum issues i will address next spring. The mast step is not designed for wedges, Spartite. The last yard installed a bolt in the mast to fasten the “hold down” that had to be cut off- now to figure the best way to install the fitting in the carbon fiber spar, in a way that it leaves a smooth mast to slide past the Spartite when pulling the stick for the winter. I also have to figure if my “varnish” is 2-part, rather than traditional. I hve to invest in a new sailcover and, eventually, a dodger. Of course, the list goes on.
I just finished the 4th season with a carbon fiber mast in my Nonsuch 33.
My understanding from the mast designer, Ted Van Dusen, is that one must use a Spartite collar rather than wedges as the carbon fiber cannot tolerate the point loads that would be induced by wedges.
You talk about the mast slipping through the Spartite when removing or stepping the mast. I think that is incorrect. My Spartite collar is adhered to the mast and purposely not adhered to the deck collar.
On the recommendation of Ted, I also had the inside surface of the deck collar machined to remove the raised sections that separate the wedges and at the same time, a taper was created larger at the top and smaller at the bottom. The point of the taper is to immediately remove contact between the Spartite collar and the deck collar as the mast rises out of the step.
My yard generally hates Spartite collars because of the friction removing and stepping the mast. They love my Spartite collar because of it’s taper.
My hold down utilizes a T-ball fitting installed into a short slot in the mast. The mast was delivered with the fabricator’s slot on the forward side of the mast. As the slot must be on the aft side of the mast, I had to make a slot myself with the mast stepped.
My slot was created by drilling two holes, one above the other. I then connected the holes with two saber saw cuts which completed the slot. I’m recollecting the slot dimensions as 3/8” wide x 3/4” tall. The slot needs to allow the T-ball to enter when turned 90 degrees but able to retain the T-ball when the T-ball is turned to it’s operating position.