Boom Reinforcing Sleeve installation

Youi cut the spar in half to push the endcap out?

While I did not cut my boom in half, I will agree that it was a lot of trouble to remove. Various mechanical means such as using pliers, drills and jig saws proved worthless. I ended up using a small blow torch and melting it off.
No, what AlanD is saying here is that you drop something down the gooseneck hole on the boom. You should be able to fit something through this plug and it will go straight through and knock the end one out.


Former ISAF Laser Measurer
Youi cut the spar in half to push the endcap out?
Yes. Cut the spar where ever it's convenient. For a top section being converted to boom, cut it so that it's the correct length for a boom. For a boom that isn't going to be re-used, cut it anywhere other than in the vicinity of the sleeve. Cutting is the quickest and easist technique.

If you are just wanting to remove the end plugs. For a top section, put the bottom plug into a vice and twist the mast so that the plug comes out. For the boom, as previously suggested drop a steel rod down through the gooseneck fitting plug or drill out the vang tang and forward mainsheet saddle rivets, so that sleeve is loose and use it to knock the other plugs out. Remember that sometimes the plugs are being held in by rivets and these rivets will need to be drilled out.
First, be sure to drill out the rivets properly. That means not drilling all the way through, but drilling off the heads and punching out the rest, just as airplane mechanics to. I wrote a post on my blog about it with some photos:

To elaborate on BJ's description of how to place the boom sleeve,

  1. I first drilled one hole in the sleeve for the boom block strap. After making a mark at the forward end of the sleeve aligned with the hole, I pushed the sleeve into the boom. The mark helped me get the holes in the boom and sleeve lined up radially, and a tape measure helped me get them aligned longitudinally.
  2. After aligning the holes a little better with a nail, I popped that first rivet.
  3. At this point, to keep the sleeve snug and straight along the bottom of the boom, I shaved down the end of thin piece of wood and used this to wedge the sleeve in place. A tap with a hammer made it pretty secure.
  4. Then I drilled the second hole for the boom block strap. It's good to use a center punch to help keep the holes concentric, and to go up in drill bit sizes in a couple of steps. As Carrol Smith points out in his book about race car preparation, drilling is a roughing process, honing is a finishing process. I considered pre-drilling all the holes in the sleeve, but decided it would be too hard to drill in exactly the right place. It was hard enough to drill in the right place even with the existing holes to guide me. Again, a reason to go up in sizes until you reach the final size of the hole.
  5. I then popped the rivet in that hole
  6. After a tap on the shim to make sure the sleeve was still snug, I drilled the first hole in the sleeve for the vang fitting.
  7. After popping the rivet in that hole, I flipped over the boom to do the holes and rivets on the other side. Only then did I flip the boom back over to do the final hole. I did it in this 1, 2, 1 pattern to help keep the sleeve centered.
  8. Once I'd placed all the rivets I pulled out the shim, and was happy to see the sleeve was nice and snug against the bottom of the boom.
Be sure to use a corrosion inhibitor. I recommend Lanocote because it makes driving out the rivets so much easier. It was also easy to tell which rivets it had been used on when my boom was built because the aluminum was pretty much pristine around those holes, whereas it was pockmarked and eroded away where corrosion had taken place. I definitely recommend getting a proper rivet puller to do the job. It was a struggle to pull the stainless rivets with my bog-standard gun, and I could tell that by the time I'd finished the job, it was about to give out because it wasn't consistently clinching the rivet mandrels.
ok so were exactly does the boom sleeve go!?!? can somebody give me the measurements of how far it his from either side of the boom?? I really need to get it in as soon as possible and im not able to find what im looking for anywere...
Thought I would add my experiences to the conversation. I have an '82 hull and recently upgraded my vang to 15:1. After reading a few more blogs I decided it was worth adding a boom sleeve too (much cheaper than replacing a broken boom). In summary, it was reasonably easy and took about 1/2 hour. Oddly enough the hardest part was taking out the old Gooseneck plug. My boom clearly bends less when vanging on block2block. Someone in another blog
mentioned reversing the upper mast as well. Have to think about that one a bit more...
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New Member
I was really surprised to see this since I last posted on this thread five years ago. Your photos are great. However, the things that stick in my mind are that I ended up using an inexpensive blow torch to remove the plugs. Much easier than any mechanical method. Also, get a heavy duty hand riveter and use steel rivets. Steel rivets are much stronger than aluminum which eventually work their way loose. I paid $20 or $30 for my riveter from an auto parts store. I've broken too many of the lighter weight ones. Coat the steel rivets insomething so you don't have issues between the aluminum and the steel.