Boom Cracked in Half

[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

[osirissail]

Booms can be put back together. I know as mine split in half right at the outhaul crank just outboard of the boom vang. The rigging shop in St Maarten put a sleave inside the boom and welded it and the two halves back together. Then they put two curved plates on the outside and riveted the three layers together. It is now stronger than ever and works fine.

[Bash]

As far as I'm concerned, all booms are heading toward crack-downs. Yours just got there earlier than others. That doesn't change the fact that it's a fairly disposable piece of gear.

Your attitude, back in the yacht club, ought to be: "Oh? Really? You haven't broken a boom yet?"

[oceansong1]

I had the same thought, amazingly fragile and very abused piece of equipment considerng the incredible forces that a boom puts up with!

The repair idea of an insert sounds like a good one. I'll start tripping aound to see who can do this work for me. Compared to a dismasting, this experience was a piece of cake. I'm just glad it happened now while close to home and not in the middle of an ocean

[Bash]

Originally Posted by oceansong1

Compared to a dismasting, this experience was a piece of cake.

Oh.

You've dismasted AND deboomed?

You might want to keep that a secret, back at the yacht club.

[Pblais]

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.

I'm thinking you really don't know. "loacalized corrosion" is not anything I've ever heard of before. You slammed it bad. As noted a sleave with a weld and she is better than new. Might look only a tad funny but it will work very well. Hope the sail is OK as they cost a lot more.

Could have been worse. The screws could have pulled out and wacked your head off. It's one of those accidents that kills people. Dead before you hit the water. It may not seem like it but you got back in one piece or I guess two peices with your body fully functional. It's fixable. Glad no one was injured. Great bar story though. I would buy a drink to hear it in person.

[Dynamo1181]

Had ours snap like a carrot, near the preventor eye. It was not doubt caused by the preventor applied and torqing the boom.
A
PS: Old boom would fit inside the replacement boom )

[osirissail]

Any holes in an aluminum tube for attachment of anything can develop "localized corrosion" which is just another way to describe the white powder corrosion aluminum is famous for when water can seep into the confined area around the bolt/screw or under paint that is not intimately attached to the metal.
- - Bolts or sheet metal screws that are too large can apply radial pressure to the tube and start local spider cracks which when over stressed (accidental/crash jibe) will allow the initial crack to propagate around the tube. The use of the proper size bolt/screw is essential along with coating the bolt/screw with anhydrous lanolin such as Lanacote, Tufgel or other similar products.
- - There are quite a few "boom brakes" on the market to help eliminate the problems of shock loads during accidental/crash jibes or tacks.
- - If you have a boom vang/kicking rod and keep it very tight to pull down the boom, a crash/accidental jibe will put severe stress on the boom at or just beyond the attachment point on the boom.
- - As others have mentioned booms really take a beating when not properly managed to reduce shock loads. A flogging sail with a loose sheet also whips the boom every which way introducing shock loads. It is advisable to really pay attention to what you are allowing your boom to do in order to avoid that mentioned hazard of having a boom break while out in the "middle" of the ocean.
- - Be especially careful if you have loose footed mainsail as when/if the boom snaps you will have two ragged edge poles swinging wildly about trying to find your or anybody else with you's head. My boom has sail slides along the boom so that when it snapped in half the sail kept the aluminum tube under control.

[maisis00]

I once heard an old salt's story about a makeshift boom repair while at sea. The one I heard about used a piece of metal piping as a sleeve (about 2/3ft in length) to slip over the two pieces of boom right at the breakpoint. As I remember the story, some slight trimming of the boom with a hacksaw ensued. Then using a drill they put 4 holes in the sleeve and boom. There were 2 vertical holes each one about 6" from the sleeves ends and 2 horizontal holes each one about 8" from the sleeves ends. Then using 4 really stout bolts and nuts (probably some washers involved too) they cranked the sleeve and boom down tight. Supposedly he easily sailed on about 700+ miles to port after this repair. Or that's how I remember the story relayed to me.

I've meant to get an opinion on this account from other experienced sailers but I always forget. I guess it seems feasible but could this kind of repair actually last for any serious length of time? Although the guy never told me as much I always just assume he later replace the boom fully, but who knows.

[Pete7]

Originally Posted by maisis00

I've meant to get an opinion on this account from other experienced sailers but I always forget. I guess it seems feasible but could this kind of repair actually last for any serious length of time? Although the guy never told me as much I always just assume he later replace the boom fully, but who knows.

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

[delongdubois]

We repaired an anodized aluminum boom with a sleeve and aluminum epoxy and screws. The sleeve was constructed of two halfs of marine grade aluminum (6mm), formed (braked) to match the interior profile of the boom and inserted to a close tolerance with aluminum epoxy bedding and then screwed with stainless machine screws that were threaded through the boom and the inner sleave. These were bedded with tef-gel to minimize corrosion and provide some adhesive strength. The repair was not a simple process to match up the two boom ends and insert the sleeves etc but the result is a stronger boom with the aesthetics marred only be the pattern of screws. btw, the screw pattern was something we debated and researched with Brion Toss and other riggers and ended up with screws spaced out about a foot from the break on both sides and approximately at every 2" around the boom.

Good luck.

[sailorboy1]

Lot of boom repairs mentioned; does anyone have a price difference between these welding type boom repairs verse replacement?

[delongdubois]

Our repair cost was about $350 - $300 for the aluminum and fabrication and $50 for epoxy and screws/taps/tef-gel etc.

Welding aluminum is a tricky business and must be done with care as you can change the temper of aluminum and make it very brittle - go with a real pro for this one.

Replacing a boom may cost a little if you find the right one in a riggers "recycle" bin or it might go up to several thousand dollars for something new(er) - then you have to budget in new fittings etc. It all depends... and your mileage may vary!

[Pblais]

Replacement is more the problem of time. We had a club member lay a 25 ft boat mast into a day mark in a pretty freak accident. It took a year to get the replacement mast / boom delivered. It would vary by type and component ordered but the shipping alone on a boom isn't cheap. The boom comes bare so you have to add all the little door prizes. Some might be reused from the old boom but it's a lot more work to replace a boom. You still need someone that knows how to weld this material to do a sleeve. The sleeve could be fabricated locally.

[oceansong1]

You folks are right on many counts; I slammed it bad, although the boom did not hit anything, and my vang was tightly pulling it down which may have created undue stress during the gybe. Winds were gusting to 35 and possibly beyond. I was alrerady on my first reef and was focused on trying to take in my jib to put up my staysail when the gybe occured and subsequent break. It is a loose footed main sail. The good news is I dropped the boom off to a metal fabricator today. 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. Not sure the price but I'm just very happy I don't have to go through the trials of finding another boom used or otherwise.