Laser boom reinforcement

Thread starter #1
I am trying to reinforce two older laser booms. I have tried to obtain the laser boom reinforcement kit to no avail. I have one kit on order with West Coast Sailing with no expected delivery date and recently inquired at APS who also acknowledged no idea when or if they will ever receive kits. With that said I purchased aluminum tubing 6061 T6 ASTM. I measured the ID of the laser boom at 1.853-1.864 ". The tubing purchased has an OD of 1.75 " and wall thickness of 0.065". Others on this site report purchasing licensed kits with tubing measuring 44 mm OD or 1.73 " and 1 11/16 " or 1.69, which measure favorable with what I purchased. No other OD was available to fit inside the laser boom.

I have read other posts of how to install the tube but have one question or concern. Since the tube is about 0.10" smaller than the boom, when placed on the bottom of the boom to install the boom eyestrap rivets there results in a gap between the reinforcement tube and the boom where the vang strap rivets are to be attached. If one installs a vang strap rivet on one side of the strap I believe the reinforcement tube will be pulled to one side furthering the gap on the other side. See photos. The red dots are approx. location of vang strap rivets, the black dot location of boom eyestrap rivet. First photo centered, second photo if vang strap rivet pulls to one side.

My concern is if you tighten the rivets with a gap something should move to close the gap: the vang strap, the boom or the reinforcement tube. I don't care if the reinforcement tube distorts I just don't want the boom to. I have not seen this addressed elsewhere and am curious how other installers have dealt with this.

Lastly for those attempting to remove the gooseneck plug, I inserted a brass punch rod through the gooseneck hole and then raised the boom to vertical, gooseneck plug down. With a few quick up and downs with the boom causing the rod against the plug, it came out undamaged. Took less than one minute. I don't take credit for take his technique, I read it elsewhere but others have told of the horrors removing this plug.

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Thread starter #3
Emilio,

Thank you for your response. I have some further questions. The photo shows a section of the sleeve material which has not been finished (filed/ sanded) following cutting. The aluminum tube sleeve was spec. at 0.065" and measured 0.062-0.070 at various locations around its circumference. Commercially this is about the thinest tubing I found available in this diameter. A 0.058 wall thickness is rarely available but not common and is twice the expense. On a previous thread a person reported a licensed sleeve with a width of 1.8mm which is 0.071", well within what I purchased and slightly thicker.

In absence of a class legal supplier I believe I have a sleeve within the dimensions reported on this site for class legal sleeves. Per your comment that the sleeve does not appear class legal, what are the class legal dimension, OD/ID diameters and tubing thickness? I was never able to identify these specs just length. As an aside I won't be racing class events so it doesn't matter, just trying to understand your comment.

As you indicated i am aware to install the mainsheet block eyestrap first. More to my original concern, during your installation of these sleeves how have you dealt with the apparent gap at the vang sleeve per my photos and potential distortion? The vang strap may provide some extra support. It just doesn't seem like a rivet will pull the sleeve tight to the boom tube but I may be wrong.
 
#4
I have no idea what the wall thickness is in the "class" sleeve. I would have to take it out of my booms to measure it.
From the picture your sleeve looks thicker but it might be just the way it's cut.
I think you're worrying way too much. The sleeve will be tight to the bottom of the boom which is where the maximum bend is. If there is a gap at the vang strap it will be very small and will not make any difference structurally.
Slap it in and go sailing!
E
 
#5
Constructing a Laser boom is only legal if all the parts used, including the inner sleeve, are new builder-supplied parts (such as gudgeons, boom blocks, vang key fittings and end-caps) or original parts (i.e. a snapped top-section and the inner sleeve from a old legal boom). If you supply your own tubing - no matter how closely you try to match the original - it will not be legal. However legal it might be (and only you will know whether you used legal parts or not), I would hesitate to turn up at an event with a home-made boom. It would probably not have the Laser sticker - you could hack-saw the top-section just after the sticker, but then you would have to make another cut at the other end and re-fit the end-cap. Even if you know that you have used legal parts, it is unlikely to be accepted at an event with any degree of scrutineering.

One challenge is getting the measurements correct and drilling the holes in the correct vertical alignment. I advise fitting the semi-circular vang key fitting first, and drill the other holes so that they line up vertically.
 
#6
The official sleeve is no longer available, at least in the US.
Fit the mainsheet block first; it's easier to align and will hold the tube while you drill and install the vang.
Don't bring your boom to a world championship; everywhere else you'll be fine.
E
 

LaLi

Well-Known Member
#7
Don't bring your boom to a world championship; everywhere else you'll be fine.
World Championships are sailed with supplied equipment; everywhere else a "home-built" boom is illegal as well.

If you can't get real sleeves (PSA Sailing in Australia might actually have them), get new booms. If the boats will be used for recreational sailing only, then forget the whole thing. You won't need to sail as fast as someone with a stiffer boom. If they break, then get new ones.

_
 

Wavedancer

Upside down?
Staff member
#8
I read (on another website, but from a reputable source) that LP is still having cash-flow issues. US dealers have to pre-pay and then they have to wait a long time for their orders to arrive. No way to run a business!
 
#9
If you want a genuine sleeve then PSA will ship you one: Boom Sleeve - PSA Sailing Online Shop
For club boats when I've made booms from broken top sections, you can also make a sleeve with a section of old boom with a slit cut in it so the sleeve will fit snugly in the "new" boom. Takes a bit of bashing to get the sleeve in place but works really well
 
#10
World Championships are sailed with supplied equipment; everywhere else a "home-built" boom is illegal as well.

If you can't get real sleeves (PSA Sailing in Australia might actually have them), get new booms. If the boats will be used for recreational sailing only, then forget the whole thing. You won't need to sail as fast as someone with a stiffer boom. If they break, then get new ones.

_
Master worlds are not sailed with supplied boats. Showing up with a home built boom at a master worlds might cause you problems. I doubt you would have any problems anywhere else.
You don't need a sleeve to be faster, but to prevent your boom from breaking. And w/o a sleeve it will break which in a blow will make for a unpleasant experience.
Sleeve it and go sailing.
E
 

thieuster

Active Member
#11
WC Aarhus in 2018 had supplied boats for the contenders. Largely supplied by Segelmayer (GER) and Sailcenter (NED). Sailors had to bring their own 'software' materials. During other WC's, like the U18 in Kiel last year, sailors brought their own boat or chartered one from Segelmayer.

The hassle of inserting a new reinforcement would be too much for me. It's easier to go out a find a new-ish boom. I do agree with mr Castelli about the hazard of a breaking boom! Given the position of the sailor and the boom, I am afraid It will go to pieces just above your head or right in front of your face. I wouldn't risk that.

Menno (who's off the grid today. Sailing!)
 

LaLi

Well-Known Member
#12
Master worlds are not sailed with supplied boats. Showing up with a home built boom at a master worlds might cause you problems. I doubt you would have any problems anywhere else.
Masters Worlds are sailed mostly with chartered boats, especially if they're outside Europe. Any illegal equipment should cause problems everywhere where you're racing. I find it troubling that we're even trying to find a certain level where at least certain class rules don't supposedly matter.
You don't need a sleeve to be faster, but to prevent your boom from breaking. And w/o a sleeve it will break
You can think of it this way: the first 100,000 (or so) Laser booms were sleeveless. The class was thriving at the time and everyone was happy. Did a majority of those booms break? Of course not, just a big enough percentage to warrant a simple upgrade.

So... I wouldn't worry about those booms. If you're planning to race the boats (at any level), then buying new ones (or even used but sleeved ones as Menno suggested) makes sense.

_
 
#13
You can think of it this way: the first 100,000 (or so) Laser booms were sleeveless. The class was thriving at the time and everyone was happy. Did a majority of those booms break? Of course not, just a big enough percentage to warrant a simple upgrade.
I think this is because those boats had the old vang system, I have always heard the boom sleeve was added to accomodate the extra force applied to the boom by the new vang.
 

LaLi

Well-Known Member
#14
I have always heard the boom sleeve was added to accomodate the extra force applied to the boom by the new vang.
That is incorrect in two ways. First, there is no "extra" force on the boom. If your leech tension/mast bend is the same (which is what you're aiming for), it doesn't matter how much purchase the system has - more of it merely makes the goal easier to achieve. The loads within the rig are identical.

Second, there's the timeline. The first, shorter (65 cm) boom sleeve was introduced sometime in the 1980s, the current longer (90 cm) one around 1997, and the "new" vang in late 2001. So no cause and effect even temporally.

That said, of course there is correlation between boom breakage and high vang tension. But if anything, the "new" vang cleating fittings make it easier to release that tension, and therefore more likely leading to fewer, not more failures.

_
 
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