Boom Cracked in Half

[Bash]

Originally Posted by Pete7

Has me wondering how well our loose footed mainsail would set if we took the boom away completely, put the main sheet on the clew and clipped is to the pushpit rail

Pete

That's certainly the approach I would take. A loose-footed main with end-boom sheeting would be fairly simple to jury-rig on all points of sail without any semblance of the boom remaining. Especially if you had four snatch blocks available to help create a new virtual traveler. You'd lose a bit of performance downwind, but on anything less than a deep broad reach, you'd be gold.

[Mi2ndWind]

"He sounds confident he can fix it by welding the aluminum at the break and creating a type of support sleve which he will fasten on the on the outside of the boom." I would not trust this method, I would recommend an internal sleeve about 2' long with plug welds to give strength to the boom, then the external welded bracing shorter than the internal. Relying on the external collar alone may cause an eventual tear where the edge of the collar is welded to the boom due to flexing and work hardening. Internal stiffening with plug welds will prevent work hardening of the aluminum at the edges of the circumference welds. It has been my experience with aluminum that it cannot be treated like steel as far as welding repairs go, staggered edges and well supported joints will make for stronger repairs.

[oceansong1]

I went with both, an internal and external sleeve. Also had the welder reinforce the gooseneck

[Jack Hattingh]

I'm new at sailing but can add some advice regarding corrosion on booms or masts. ALWAYS apply a "non-oxide" paste i.e. Denso, to any screws or plates or other secured fittings of dissimilar properties i.e stainless steel to aluminum or brass to aluminum or stainless steel.

[JPA Cate]

Hello Jack, I can see this thread has been revived.

Our boom broke once, in an unexpected gybe, where it broke was immediately aft of the vang attachment. Upon examining the boom stub, the breakage was partly due to our habit of cinching the main sheet down tight--you could see the area of old metal fatigue, and the new tear. The repair consisted of inner and outer sleeving; in our case, the outer sleeve is screwed in and the rigger who did it, used lanolin for the anti-seize/anti-corrosion. Prior to that, we used to use the silver anti-seize.

Ann

[Siberian Sea]

I had an uncontrolled gybe and also damaged my boom. Part of my mistake was to improperly attach my boom brake mid boom instead of hanging it on a line that is attached to both boom ends. If I had done the latter the force applied to the brake would have placed compression upon the boom instead of single point mid boom. Now I seek a 16 foot boom if anyone has one for sale.

[stainless guy]

Your boom is likely 6000 series extruded aluminum with cast ends welded or riveted on. 6061 is a very weldable alloy, any welder with a decent amount of aluminum experience should be able to fix easy enough.

[roverhi]

Originally Posted by oceansong1

Has anyone had the experience of your boom breaking?

Yesterday singlehanding from Block Island to my home port on the Long Island Sound, was in heavy winds and suffered an uncontrolled gybe on my Morgan 38. My boom cracked in half! it was a clean break right in the location of a small fitting held with 2 stainless screws. Boom is made of cast aluminum and the machine screws holding the fitting are stainless. There is evidence of mild localized corrosion at the site of the break and I'm assuming dissimilar metals caused electrolysis which led to corrosion. However, attaching fittings to a cast aluminum boom with stainless screws is not an unusual arrangement.

I'll try tomorrow to find metal fabricator in the area and get some opinion on repairs. Any suggestions or similar experiences or effective repairs

Have never seen or heard of a cast aluminum boom. Booms are aluminum extrusions with castings for either end. Assume the gooseneck casting is what cracked. You could try having it welded back together but outcome is iffy because of age of the metal. Often welding old castings that have been subjected to a corrosive atmosphere just don't work. Give it a try but cross your fingers that you get lucky. Also welds in aluminum are something like a 1/3rd less strong than the original casting. Unlike steel welds that are often stronger than the original. P

Probably a long shot but you could try and see if you can find a replacement for the fitting. If you can identify the original manufacturer and they are still in business, might find the part. I've found parts for out of production stuff from breakers that have a ton of old aluminum booms. Last but not least a new aluminum boom may not be too expensive. Mack Sails has supplied me with two internal reefing booms at less than a boat unit including shipping. Mack Sails – Sailmakers