| SJ23 Tech Tip F20, (Issued 1999-01-12) Bob Schimmel | |
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Boom Gooseneck - Repair a Worn One. |
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 With
years of use the bolt holes in the gooseneck eventually wear out, the
goose neck jams and it may be in danger of falling off during rough
weather. It's amazing how
many sailboats have worn goose necks. Panache's mid section was round
aluminum, which made for a very weak gooseneck.
I believe this section was factory original. Fortunately, the
solution for a SJ23 is as simple as replacing the worn mid section
with 1" square aluminum stock. Square stock is available at
a metal yard or at a larger chandler where metal is sold. The cast
portions of the gooseneck don't
seem to wear out, which is nice.
Construction - Using the old mid section as a template, line it up against the 1" square aluminum stock. Mark the overall length and the location of the holes. Drill the two 1/4" holes at 900 to each other. Cut to length. (This is a great time to correct the length if the old one was too long). Be careful that you don't cut it so short that the boom crushes into the side of the mast when fully swung out. File the all corners to remove sharp edges. The mast end of the new mid section must be rounded (constant radius) to permit sideways turning of the goose neck. You may as well replace the two stainless steel bolts so you start with a new bearing surface. Also use new nylock nuts. Assemble the gooseneck and ensure you have 900 of free swing, port and starboard. (The boom MUST be able to swing all the way out against the shrouds with no binding in the joint). If there is a gap between the new mid section and the flanges of the casting on the mast, insert a stainless steel shim or washer. The shim must be a hard metal to prevent wear. The gooseneck MUST fit snug. If the old 1/4" bolt holes are worn oblong, drill them out to the next size up, 5/16" or 3/8". Drill through to the hole on the far side so both holes line up. The replaced mid section, with it's larger bearing surface, will probably outlast the original round stock. You can now sail with a quiet boom!NOTE: When looking a later serial number SJ23s, I
noticed that Clark
used square stock aluminum for the gooseneck and none of them are worn the
way Panache's goose neck was. I think they installed the square section to
reduce the wear. |
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