sailing casita

We found some cracks in our boom. That kind of ruined our good day.

There are four cracks in two locations on the boom. One location is over the vang attachment, the second is near the center boom gallows landing. Looking in the cracks with a 20x glass it looks like there is intergranular corrosion in the metal. This flaw is usually present when the spar is manufactured. I think this spar was doomed from the start.

After installing the bimini and enclosure we moved the mainsheet traveler forward of the dodger. The original mainsheet attachment was at the end of the boom to a traveler on the curved cockpit cap rail. This modification may have increased the stress on the boom, we did not install a plug/doubler inside the spar to increase it’s strength in the area of the mainsheet attachment. I really think the spar was cracked before we moved the mainsheet, we just did not see it under the paint on the boom.

Finding a new boom was a scary thought and can be expensive. We needed to keep the midboom sheeting, so we needed a larger spar. We needed to keep the current reefing system and outhaul. We needed to keep the rigid vang. We ended up finding a deal at US Spars in Florida, they had a few boom kits that had a cosmetic flaw in the clear anodizing and were discounted. After looking at the specs, the dimensions of the sheaves inside the toggle fitting, and verifying the boom would fit our boat, we bought one over the phone.

Z480 Boom kit, 3 mainsheet bails, 3 reef bails, extrusion cut to length: $989. 4 sheaves: $22. Rigid vang slider: $127. Preventer bail: $38.

Total with packing and shipping: $1688.53,

We could not see any flaws in the finish, maybe a sheen or the color was not exactly clear, we don’t know. It looks good to us.

The old boom toggle fitting was modified sometime in the past to incorporate reefing lines running through the boom. Extra sheaves were installed in the fitting. We never liked the way the fitting was loose in the spar, the fitting was able to move around a bit, you can see a gap at the connection point. One reef line was run outside the boom with extra blocks and rigging.

This is the original design for our reefing system.

In the new toggle fitting we removed the Zspar line cams/jammers and installed extra sheaves on the same axle in a new location. There are now six lines exiting the forward end of the boom. There are the first and second reef, an outhaul, and a flattening reef. The fitting to spar attachment is much better looking.

The boom kit and parts were shipped in a double wall tube. Looks like a culvert for road building. We sold this tube locally on Craigslist.

Temporary mainsheet run to get the blocks on the boom in the correct location.

We had to change the sail slugs on the sail and the stack pack. The new boom uses a rope track instead of flat sliders, not a big mod just time consuming. I like the natural finish instead of white paint. And I really like the larger spar.