Mainsail & Boom

Last update March 7, 2004

The Boom

The outer casing is .5" aluminum with a 49 wall and is 37" long. This is sleeved with .375" aluminum with a 65 wall. The length of the sleeve will depend on the gooseneck design for the mount to the mast. The boom was powder coated for esthetics.

The Gooseneck and Vang

The mounts to the mast and the vang were designed by Mike Zellanack of St. Petersburg, Florida. Mike makes rigging parts for the EC12 class and his contact and wares can be seen on the class website. They are fashioned from solid aluminum and grooved to fit in the track slot of the mast and held in place with set screws. The ball swivels are from Germany and installed with 4-40 machine screws. The shaft is sanded slightly to fit in a .375" aluminum sleeve with a 35 wall about two inches long. The shaft is glued in with a pin. The sleeve assembly is then installed in the boom with two #2 screws.

The vang mount uses the same ball swivel with a 4-40 threaded shaft into the tube of the vang. The mount to the boom is fastened with 4-40 machine screws. The entire tube of the vang rotates for the adjustments.

The attachment of the boom mount should not be made till the complete rig is stood on the deck. This mount can be taped to the boom so that all adjustments to the rig and sails can be made. Then placement of the mount for the vang should be made with care for a neutral location between where vang adjustments that are needed. It would not be uncommon to have additional threaded holes for the mount. These would allow re-referencing a nominal position of the mount if needed.

 

It has been found that a vang on this J-Class needs greater adjustment range than on other smaller models. Sometimes these adjustments may exceed reasonable pressures on the gooseneck and distort the mast.

 

Mainsail

The main is attached to the mast with a jackline and sail hanks (preparation process). The hanks used here on the Paris mast are 1.6mm double sleeves found at good saltwater fishing outlets. 130-pound Spectra compound line was used for the jackline.

The mainsail luff was marked at 4.5" internals for installing the sail hanks. Dacron sail repair was cut into circles with a quarter coin, folded in half, peeled and installed over the marks. They were then cut out to fit the sail hank. The jackline is threaded using a 5" needle that can be found at a large chain fabric store. It was found here that this must be done before the hanks are crimped to fit in the mast. After the hanks are installed secure the line with tape and crimp the sail hanks. A small crimper was made here by dulling the jaws of a nipper. Be careful that the nipper finds the center of the sail hank.

A hook is used to attach the jackline to the crane at the head. A loop was placed in the foot of the jackline that would then receive a hook and line from a bowsie attached to the base of the mast to draw it tight.

The downhaul has a line through the tack grommet with two loops to receive another hook from an adjuster like the jackline. This line bisects the gooseneck mount.

The clew adjustment is a line with a loop to a CL connector to an adjusting ring. The loop through the clew grommet is to hold the clew to position when pressure on the sails.

Headstay

There is no disconnect of the mainsail head from the crane other than a knife. A single loop of line is tied with a square knot and adjusted to a close fit with the crane. The knot will slip if tightened with two pairs of pliers when using Spectra line. It will not slip in use. This is a quick installation and removal with no complications.

These four connections will allow the mainsail to be removed from the mast for transport. The stay loop at the clew to the boom will slip off the end when needed. The installation or removal takes only 10 minutes when practiced and 60+ year old brain cells are engrained.

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