Firefly Rerig - the beginning

My L-7 trimaran was dismasted in the 2015 Race to Alaska. Her 33' aluminum wingmast, salvaged from a SuperCat 20, failed in buckling while we tacked up the Strait of Georgia two days into the race.

I'm re-rigging Firefly with a new (to her) spar, and reusing most of the standing rigging which had all been replaced in 2015. The new rig will be very similar to the old: a fractionally-rigged rotating aluminum spar, 33' long, equipped with a pair of stainless wire diamond stays. The spreaders will be of tubular carbon fiber and swept back about 15 degrees. The masthead and mast socket assemblies will be fabricated of structural FRP and carbon fiber. Two internal halyards, one for the main and one for the maxi-reacher, will roll over two rope sheaves in the masthead fitting. The jib has a zippered luff sleeve with an internally looped halyard. Instead of the old polyethylene 2" mast step ball, the new rig uses a 1 7/8" steel trailer ball (as did the kit L7s) atop a plywood/CF mast step. The step has a few inches adjustment fore-and-aft to allow for tuning of the helm balance and mast rake.

Main furling and reefing is provided, as before, by a roller furling boom arrangement. Two rope clutches near the mast base secure the halyards. Blocks on the mast base allow the halyards to be led aft to the cabintop winches.

There are no electrical or antenna wires in the rig. Running lights are on deck and the VHF antenna is attached to the stern pulpit.

The replacement spar is a 7"x3.75" flattened oval section, similar to a LeFiell OM1C . I bought it used from an individual who planned to re-rig his Cal 25 with it (!). This sailor had bought it from a boatyard where it had been taken off of a boat and abandoned. The spar is remarkably free of damage and corrosion and is exactly the right length and section. Furthermore, there was little in the way of hardware attached to the mast and it hadn't been hacked on. Straight and free of dings, the spar will serve perfectly.

The first step was to strip off all the old hardware, tracks, and the spreaders.

Next, I cut off the welded-on masthead fitting which, being designed for wire halyards, wasn't suitable for re-use. Furthermore, due to the positioning of some of the old hardware, I decided it was better to rig the spar upside-down to its previous orientation - which meant the masthead fitting had to come off anyway.

After that, I carefully laid out all the positions of new hardware and rigging, using both the old spar and the L-7 mast plans as a guide.

Since several spots on the new mast should be reinforced with doubler plates, I wrapped up by measuring for those, as well as for doublers for a few repair spots.

Back at home, I cut the doublers out of 1/8" 6061-T6 aluminum plate.

Doublers and patches for the mast nose were cut from 1/8" wall 6061-T6 tube with a 3.75" ID.

All these doublers will be mounted to the mast with West G/Flex, prepped by the aluminum procedure in the G/Flex literature. Gougeon has found that aluminum/aluminum bonding with G/Flex achieves a tensile strength of 2590 psi with a simple prep procedure. This is an order of magnitude stronger than rivets, although the doublers will be pinned in the corners with small rivets as a backup.