Main Boom

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 aesthetics.

   

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. (Mike is no longer in operations; 2010)

  

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.