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bred2shred
Joined: 02 May 2000 Posts: 989 Location: Jersey Shore
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Posted: Fri Aug 08, 2014 11:34 am Post subject: |
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Rinsing an aluminum boom (or any other aluminum part) with fresh water after sailing in salt water will greatly reduce corrosion. That said, cleaning every little nook & cranny as well as "sealed" areas of the boom will be difficult. If I used aluminum booms, I would be super vigilant about disassembling and rinsing it after use and storing in a dry location. Really what we're talking about is cyclical loading, galvanic corrosion, and stress corrosion cracking (SCC). These are all factors that can severely reduce the strength of aluminum components and ultimately cause failure. Carbon booms are, for all intents and purposes, are not affected by galvanic corrosion or SCC. They can also withstand a higher rate of cyclical loading before failure when compared to aluminum.
That said, no boom is immune to poor design. I cracked several older Chinook carbon tail pieces on their first generation carbon booms. I have also broken two carbon triple clamp boom arms after several years of use. So if you're looking for a boom that "won't break", that boom doesn't exist. If you're looking for a boom that is the stiffest possible construction, then carbon is the material of choice.
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kevinkan
Joined: 07 Jun 2001 Posts: 1661 Location: San Francisco
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Posted: Fri Aug 08, 2014 1:24 pm Post subject: |
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whitevan01 wrote: | kevinkan wrote: | dennis_c wrote: |
Those MS front ends are stiff but heavy. |
As far as stiffness goes, I rank them from stiffest to least stiff:
1-Streamlined
2-Maui Sails
3-Chinook Pro-1
4-Simmer |
What testing did you do to determine relative stiffness? |
nothing scientific! just sailing. haha
But I have used all the booms and even swapped some boom heads onto different booms in the past. I routinely use the Maui Sails and Streamlined booms and heads... sailed the Maui Sails and Chinook Pro-1 carbon in Baja last winter... have a Simmer boom in the van too.
One thing to note about this whole discussion is that not all aluminum booms are equal and not all carbon booms are equal... there's a big variety in both in terms of stiffness, features, bends, etc... some carbon booms actually have a lowish carbon content. I remember when I worked for NP, my X7 wave boom was excellent, but some later models around 2006 or 2008 were only 65% carbon, and you could feel the difference.
I'm somewhat spoiled and was fortunate to have access to good gear when I was learning (worked at a shop). The first boom I ever bought was a Windsurfing Hawaii aluminum (power taper or something, i don't remember the model) and I had to wait a couple weeks for it to arrive. The shop owner went on vacation and said I could borrow his Fiberspar Posi-Grip 150 while he was away. I used it and it was nice, but not $550 nice! I was really excited when my boom finally arrived, used it once, sold the Windsurfing Hawaii, and ordered a Fiberspar. Even as a relative beginner, the difference was apparent. I guess that was in 1998 or so. I also remember liking a NP alu boom w/ beige and black grip ~2001 or so... although I distinctly remember doing my first duck jibe with it and noticing how slippery the alu tailpiece was compared to the ridged Fiberspar tailpiece.
Carbon booms are definitely a luxury item... they're not for everybody and not all are worth spending extra money for. They are extremely expensive, but for some they are worth the extra expense. While carbon's benefits are amplified with large sail sizes, they are also quite noticeable for smaller sails too. After stiffness, I find that tail/swing weight is the next biggest differentiator b/w booms (carbon vs alu, or heavy vs light). And yes, I've sailed modern moncoque alu booms like the Pro-1 Alloy, Aeron MCT series, Simmer, etc.. _________________ Kevin Kan
Sunset Sailboards, San Francisco CA
http://www.sunsetsailboards.com
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isobars
Joined: 12 Dec 1999 Posts: 20935
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Posted: Fri Aug 08, 2014 3:07 pm Post subject: |
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whitevan01 wrote: | What testing did [Kevin] do to determine relative stiffness? |
Out of the wrapper, I do the obvious: step on one boom arm and pull up on the other arm with one hand. That's often conclusive (extreme case: one boom many years ago kept going until that hand was over my head.)
if that test is inconclusive, I stand a yardstick (I suppose one COULD use a meterstick, presuming such things exist ) beside the boom to measure deflection at some subjective "max" effort.
Inconclusive still? Then WTH? ... close enough. We pull not only outwards (radially) on the boom, but also vertically, so I then I mount the boom on a mast, stand the mast up, and pull down on one arm. This often separates the I-beams from the noodles, big time.
Besides, WSMag tests concluded that speed is not related to stiffness with booms any more than it is with hulls, so close enough is good enough. |
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kevinkan
Joined: 07 Jun 2001 Posts: 1661 Location: San Francisco
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Posted: Fri Aug 08, 2014 5:04 pm Post subject: |
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also when i ranked stiffness, I was ranking the boom heads not the booms, although if i were to rank the booms that I used in the sizes that I use them I think the order would be the same.
also, windsurfing is all about feel (at least for me... I don't race), some people like stiff, others like more give. I remember when I was relatively new to windsurfing and i had high carbon content stuff... i got on somebody else's sail w/ lower content mast and alu boom, and everything felt so dampened and smooth... a plus for somebody just struggling to sail over chop. If I were to do the same comparison today, I probably would think that rig was more mushy and dead. _________________ Kevin Kan
Sunset Sailboards, San Francisco CA
http://www.sunsetsailboards.com
https://www.instagram.com/sunsetsailboards
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spennie
Joined: 13 Oct 1995 Posts: 975 Location: Thousand Oaks, CA
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Posted: Sat Aug 09, 2014 11:03 am Post subject: |
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+1 from Spennie, excellent post, Kevin! _________________ Spennie the Wind Junkie
www.WindJunkie.net |
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GURGLETROUSERS
Joined: 30 Dec 2009 Posts: 2643
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Posted: Sun Aug 10, 2014 4:10 am Post subject: |
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Eight years ago I bought two carbon booms (long and short) at the middle of the price range, from a small specialist company with a goodish reputation. (M &K.)
The long one (bigger sails) snapped an arm at the head last year, but the short one is still apparently sound, despite the usual beatings in 'tough' conditions.
I replaced both with a pair of new latest North alloy booms (special deal from friend - new design said to be almost as good and durable as carbon). I use the long one turn about with an old, built like a bridge, Chinook alloy which I Laid up eight years ago after buying the carbon (dismantled, cleaned, oiled, and still sound). But I'm still using the short carbon boom, with the new North alloy waiting, and as yet unused.
I may not be correct, but it seems that long carbon booms are the more prone to failure than the shorter ones, in that the tubes at the head area are not sufficiently thickened and tapered to stand the extra leverage of long tubes and big sails. (Mine wasn't - a high stress area!)
Perhaps it makes more sense to use short long lasting carbon booms, but not the very expensive long ones, unless they actually are thickened and reinforced at the head (most seem to snap there) to take that extra strain. That's something the adverts don't tell us. |
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cgoudie1
Joined: 10 Apr 2006 Posts: 2599 Location: Killer Sturgeon Cove
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Posted: Sun Aug 10, 2014 10:05 am Post subject: |
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I have carbon booms for sail sizes 3.2 to 9.5 (that would be 4 booms, because I try not to run a boom fully extended). I bought them all new,
but at considerably less than retail. The oldest is an HPL Hybrid.
I have replaced the front end on it twice now. The arms are still going strong, and the thing has got to be at least 10 years old. They all
are worth every penny I paid, but the huge one that rigs the 9.5 is
most critical. It was also the most expensive at about $350. Frankly,
I'm addicted to the positive feel of the things, even with a 3.7.
-Craig |
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