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Unregistered
24th September 2008, 05:53 AM
Hi fellows,
is it recommended to use a boom on the full length range or is it better to use only the lower range.
What I mean is: would you advice to use a 190-240 cm boom on a sail that requires 238 cm boom.
Booms tend to become rather soft on their upper limit and also the strength could be questionable, since only a short part of the tubes is intersecting.

Rgds,
G

Roger
24th September 2008, 07:22 AM
Hi G,
That's correct. a boom extended to near it's max. is going to be weaker and less stiff.
This will put higher loads on the front end and rear as well due to greater leverage being involved.
Extending a boom to about 75% of it's full range is OK.... any longer and you may be asking for trouble.
As far as a 238 cm clew length sail on a 240 cm boom, there's no room for adjustment (the clew length will increase as you add more downhaul) so that would not be a good match for more than just the max. extension vs strength and stiffness issues.
Hope this helps,

Sail Quick
24th September 2008, 07:46 PM
If the boom does not work properly at it's maximum length of 240cm then why would the boom maker state it's maximum length is 240cm when it should only be used at say 235cm as it's maximum length so if they stated that the boom now had a maximum length of 235cm would it be good to use it at 235cm or would that maximum length now be questionable and the boom would only be safe to use at 230cm. Surely when the boom manufacturer says the boom has a max length of 240cm it means it functions properly at that length? Or should all the boom manufacturers change the max length of their booms to %75 of what it is now immediately so that it is correct and safe?

geo
24th September 2008, 08:24 PM
I think it depends on the boom.
I have a Maui Sails 190-240 carbon boom and I would not hesitate to use it at 238. At 218 it just does not move. As a comparison, my other older carbon boom is a 180-226 and felt a bit soft when extended at 204 with my old 6.9 and even at 194 with my old 6.6. Maybe it would hold perfectly well full extended, but I would not feel safe to try.

nonopr
24th September 2008, 09:28 PM
Pricing has made all companies reconsider their boom construction. If it says is 190-240 it better work at 240 because at $700-900 a pop you bet I will send it back or ask for a credit at the store who sold it.

Roger
24th September 2008, 09:39 PM
Hi Sail Quick,
OK, you can extend your boom to 240 cm and use your sail with a 238 cm recommended boom length.
What do you do if the wind comes up....... is 2cm of additional outhaul going to "depower" your rig enough?
What if you want to downhaul your sail alot more..... you have only 2 cm more boom length? You may not be able to get any outhaul (to stabilize your sail) at all as the clew length will have "grown" to well past 240 cm.

As Geo suggests, it depends on the boom.
I have some booms I run nearly fully extended, but when I'm out on them I don't feel real secure as they bend, flex, creak, etc.
I have other booms that just feel soft and flexy once I extend them beyond about 75%.
So, if I'm sailing alone, or far offshore, or in a race, I'll use a boom that I know I can trust and I won't extend it to the max.
I've broken booms and had to sail the unbroken side back to the beach, or had to swim back in 36 deg. water and 40 deg. air temp.
Don't really want to do either of those "self rescues" again, so I'll "err" on the side of caution when it comes to boom extension.
Hope this helps,

Sail Quick
25th September 2008, 03:53 PM
Hi Roger:
If I extend a boom with a maximum length of 240cm to 75% of it's maximum length does that mean I can only extend it to 180cm?
I agree with nonopr that if it says 240cm on the box then I expect to be able to use it at 240cm, to only anticipate it to work at some arbitrary length short of 240cm just seems not to be logical to me.
Could you tell us which boom brands you are too scared to use at more than 75% of the maximum so I can avoid buying them?

Unregistered
25th September 2008, 04:15 PM
Hi Roger:
If I extend a boom with a maximum length of 240cm to 75% of it's maximum length does that mean I can only extend it to 180cm?
I agree with nonopr that if it says 240cm on the box then I expect to be able to use it at 240cm, to only anticipate it to work at some arbitrary length short of 240cm just seems not to be logical to me.
Could you tell us which boom brands you are too scared to use at more than 75% of the maximum so I can avoid buying them?


100% agree sailquick.
If it says its a 180-240 boom then i expect it to work properly anywhere in that range. Anything else is unaceptable.

nonopr
25th September 2008, 06:38 PM
Sail Quick: Buy Maui Sails Booms and you wont have any problems using it at 240 is the only brand I can recommend to be able to use it at 238 with no problems.

HotIce
25th September 2008, 08:40 PM
Please think safety.

A heavy weight, sailing overpowered on a fully extended boom, in cold water in a remote location is foolish.

A light weigh, sailing a fully extended boom on a warm summers day, in a popular location, on a big board and light onshore winds is a different kettle of fish.

Just because the extension range is available it does not make it right to always blindly use it to itís max range.

nonopr
26th September 2008, 12:12 AM
Hot Ice:
Windsurfing in a remore location, overpower and in cold water is foolish, not the boom been extended to the a safe setting as the manufacturer says.. Get a Partner and then you can windsurf in those conditions.

Roger
26th September 2008, 12:37 AM
Hot Ice has it right.......
Sure, you can use almost any boom at it's full extension.....any time you want.
And, you can expect the boom to work adequately from fully collapsed to fully extended.
BUT....
As HotIce suggests, there are times when it's not risky to extend your boom fully....
if it breaks, you can easily and safely get back to shore.
There are other times where the conditions (windspeed, steadiness and direction;
air temperature; currents; any other factors) aren't favorable to easy "self rescue".
For these situations, you may want to think a little harder about the risks involved.
A broken boom, well offshore, in offshore winds or currents, in colder temperatures, can quickly become a "life threatening" situation.
Once you've been in such a situation, you learn to evaluate the "risk factors" somewhat differently to get as many of them in your favor as possible.
Not saying your fully extended 240 cm boom is "dangerous" but then again it's your life that's at risk.

Unregistered
6th October 2008, 03:13 AM
Hot Ice:
Windsurfing in a remore location, overpower and in cold water is foolish, not the boom been extended to the a safe setting as the manufacturer says.. Get a Partner and then you can windsurf in those conditions.

Please think of the audience here and their safety. Are you suggesting that a manufactures boom extended to its full length is safe in all conditions and that a sailors weight is irrelevant.

When there is snow on the road I drive slowly even though the speed limit is higher.

feuser
7th October 2008, 04:13 PM
A boom extended to it's maximum length should be safe otherwise it is not really it's maximum length but has exceeded its maximum length as it cannot be used at that length. My boom did not come with a warning saying if I am fat or if it is cold don't extend it past a certain percentage of the maximum length.

HotIce
8th October 2008, 06:23 AM
A boom extended to it's maximum length should be safe otherwise it is not really it's maximum length but has exceeded its maximum length as it cannot be used at that length. My boom did not come with a warning saying if I am fat or if it is cold don't extend it past a certain percentage of the maximum length.

My 6.9 m sail did not come with a warning saying do not use it in a severe gale. I guess the manufacturer thought I would have some common sense.

IMHO it is naive to suggest that a boom is safe at itís maximum extension regardless of the sailors build and sailing conditions.

I am amused though that some people would unquestionably put their safety in the hands of a boom manufactures maximum extension.

Per
8th October 2008, 02:20 PM
Theres a lot of difference between useable and good. During the last ten years I've broken eleven aluminium booms of different brands ;-) I've now switched to Maui Sails (still aluminium) and I've bought a boom to compliment each sail so that the boom will be extended as little as possible( max 2 cm). I've never broken any of these (yet) and the stiffness is superior to a fully extended boom. I sometimes see beginners buy one boom to cover t.ex. their whole 5.5 to 7.8 range with one single boom. It's possible, but it will mean (no matter the brand) that sailing fully powered/fully extended on the 7.8 it will be difficult to get the best of the sail as the boom will flex more thus decreasing the authaul leading to more drag, more flex etc. = useable but not good...