Go Back   Starboard Forums > Free Forum

Reply
 
Thread Tools Display Modes
Old 24th September 2008, 04:53 AM   #1
Unregistered
Guest
 
Posts: n/a
Default Boom length

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
  Reply With Quote
Old 24th September 2008, 06:22 AM   #2
Roger
Dream Team - School Guru
 
Join Date: Aug 2006
Posts: 2,110
Default

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,
Roger is offline   Reply With Quote
Old 24th September 2008, 06:46 PM   #3
Sail Quick
New Member
 
Join Date: Dec 2007
Posts: 8
Default

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?
Sail Quick is offline   Reply With Quote
Old 24th September 2008, 07:24 PM   #4
geo
Member
 
Join Date: Aug 2006
Posts: 327
Default

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.
geo is offline   Reply With Quote
Old 24th September 2008, 08:28 PM   #5
nonopr
Member
 
Join Date: Aug 2008
Location: San Juan, Puerto Rico
Posts: 573
Default

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.
nonopr is offline   Reply With Quote
Old 24th September 2008, 08:39 PM   #6
Roger
Dream Team - School Guru
 
Join Date: Aug 2006
Posts: 2,110
Default

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,
Roger is offline   Reply With Quote
Old 25th September 2008, 02:53 PM   #7
Sail Quick
New Member
 
Join Date: Dec 2007
Posts: 8
Default

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?
Sail Quick is offline   Reply With Quote
Old 25th September 2008, 03:15 PM   #8
Unregistered
Guest
 
Posts: n/a
Default

Quote:
Originally Posted by Sail Quick View Post
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.
  Reply With Quote
Old 25th September 2008, 05:38 PM   #9
nonopr
Member
 
Join Date: Aug 2008
Location: San Juan, Puerto Rico
Posts: 573
Default

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.
nonopr is offline   Reply With Quote
Old 25th September 2008, 07:40 PM   #10
HotIce
Guest
 
Posts: n/a
Thumbs up Think Safety

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.
  Reply With Quote
Reply

Bookmarks

Tags
None

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +7. The time now is 03:48 AM.