myiW Current Conditions and Forecasts Community Forums Windsurfing Videos Buy and Sell Services
 
Hi guest · myAccount · Log in
 SearchSearch   ProfileProfile   Log in to check your private messagesLog in to check your private messages   RegisterRegister 
Carbon Boom Breakage.
Goto page Previous  1, 2, 3, 4, 5  Next
 
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion
View previous topic :: View next topic  
Author Message
GURGLETROUSERS



Joined: 30 Dec 2009
Posts: 1367

PostPosted: Sat Aug 31, 2013 5:22 pm    Post subject: Reply with quote

Been checking, but it's become a question of economics.

High end carbon booms, in our rip-off country, are very expensive indeed. The favoured Chinook one is over half the price of a new board! (And THEY are silly prices too!) I can buy four normal alloy booms for the price of a single good carbon one. While I agree with Puffin (whether he's upside down in the water, or otherwise) that carbon is indeed nicer, I may have to settle for less.

My old tough and rugged Chinook alloy boom was in use for over three years before I replaced it with the current broken carbon one. It is back in use again (was cleaned, checked, and oil sprayed when laid up to prevent corrosion) while I decide what to do. Assuming each new alloy boom was as durable, four would last me over 12 years.

On checking up, there appear to be many disgruntled carbon boom buyers who are bemoaning failures. No single make seems to be completely immune to problems. (A bit like snapping boards, it seems.)

One tempting possibility is the new North Gold alloy boom which claims aerospace quality construction, with close to carbon rigidity, and durability. It neatly spans the price difference between the two, but, if it is as good as they claim (built for racers) it would be a nice option.

(Whitevan - thinking of replacing my alloy Spesh Camber with new full carbon version. Don't I just love those 29er wagon wheels!!!)
Back to top
View user's profile Send private message
keycocker



Joined: 10 Jul 2005
Posts: 3468

PostPosted: Sat Aug 31, 2013 6:21 pm    Post subject: Reply with quote

GT, want a Chinook alum mono?

Last edited by keycocker on Sun Sep 01, 2013 2:23 pm; edited 2 times in total
Back to top
View user's profile Send private message
keycocker



Joined: 10 Jul 2005
Posts: 3468

PostPosted: Sat Aug 31, 2013 6:29 pm    Post subject: Reply with quote

Note to posters.no booms for sale here.
You have to order from Chinook.
I am just explaining to GT what a team riders share is.
Back to top
View user's profile Send private message
rangerider



Joined: 19 Jul 2009
Posts: 157

PostPosted: Sat Aug 31, 2013 9:11 pm    Post subject: Reply with quote

Gurgle - I'm pretty sure in heaven that the booms are weightless, perfectly stiff and balanced, they never ever break, God lavishes them on windsurfers whose bodies are no longer subject to age or injury, and they don't hurt when you hit them with your face. You may want to reconsider your position Wink
Back to top
View user's profile Send private message
GURGLETROUSERS



Joined: 30 Dec 2009
Posts: 1367

PostPosted: Sun Sep 01, 2013 3:18 am    Post subject: Reply with quote

Thanks very much K.C. I've sent you a P.M. (Provided I pressed the right buttons, that is!!)

Rangerider. ...No, I'd rather not reconsider thank you. I much prefer Whammo! Lights out, at the final curtain call.

What makes you think your vision is Heaven. Wouldn't it become a little Hellish, after the first few million years of it? Wink
Back to top
View user's profile Send private message
rangerider



Joined: 19 Jul 2009
Posts: 157

PostPosted: Sun Sep 01, 2013 9:36 am    Post subject: Reply with quote

Gurgle, I hope you take my post for what it was - a lighthearted jest. I can say with confidence that there is no reference to windsurfing in the Bible - so I am definitely out on a limb. Nonetheless I still have confidence that I will be windsurfing or something better in heaven in millions of years, with a smile on my face.

On topic - very happy with the Aeron MCT aluminum boom although I would love to upgrade to carbon
Back to top
View user's profile Send private message
bamer



Joined: 29 Oct 2014
Posts: 58

PostPosted: Tue Sep 03, 2013 4:57 pm    Post subject: Reply with quote

keycocker wrote:
We fixed carbon masts and booms in our shop for several years. In every
case in which we know the outcome - it failed.


If this was the case, the repair person simply didn't know what they were doing.

Broken carbon booms can usually be repaired and if done correctly should never break again anywhere near the same location. These repairs are generally very easy for a composites expert but would be outside the skill set of a novice.

For the repair to take and last it needs to:
1. Be strong enough to replicate the original section AND act as a bridge joining the sections that are uncompromised.
2. Taper in strength and stiffness such that there are no hinge points.
3. Be mechanically bonded adequately which requires special techniques and may require high peel strength epoxy.
4. Soften the edges of the break so they do not push on and point load the new wall from the inside.

keycocker wrote:
They make booms by orienting the fibers long ways and a repair can not duplicate that.


Booms are primarily made of unidirectional carbon that runs along the length of the tubes. You are correct that with a repair you will not get a continuous fiber run from one tube end (or section) to the other. But very few booms are actually made this way.

Unidirectional carbon is readily available, it is very easy to work with, and orienting the fibers along the length is a basic skill. So a repair can precisely duplicate the fiber orientation.

I have repaired over 20 booms and to my knowledge there are no cases where a repair failed. All the booms were used heavily after being repaired and some of these users stress and cycle their equipment in the 99th percentile.

I do not endorse boom repairs for a novice. But if done by someone competent, there is no reason whey they should not last.

Masts are very different than booms. They are designed to bend a specific amount and replicating this bend with a repair is very difficult. In my opinion the vast majority of broken masts should not be fixed. Most repairs could be made to hold, but they would not be worth the loss of performance.
Back to top
View user's profile Send private message
KevinDo



Joined: 02 Jul 2012
Posts: 423
Location: Cabrillo Inside

PostPosted: Tue Sep 03, 2013 6:34 pm    Post subject: Reply with quote

whitevan01 wrote:
GT,
nice. so are you into F1? McLaren? Button or Lewis?
I'm a Scuderia Ferrari/Fernando nut myself.


BMW SAUBER!!! well back when they were bmw ... lol

_________________
2014 Cabrillo Beach GPS CS (inside)
https://drive.google.com/folderview?id=0B1T3t6bAGX8AejJqTFg5empQNjQ&usp=sharing
Back to top
View user's profile Send private message
keycocker



Joined: 10 Jul 2005
Posts: 3468

PostPosted: Tue Sep 03, 2013 7:55 pm    Post subject: Reply with quote

Interesting. Could you give me a little detail on how you fair in uni carbon and get just as strong a repair as a continuous spar?
I know one or two industry folks with a lot of carbon experience who think that it is not practical or economical, but they have not seen a success rate like yours.
That may be why the shops here in Maui who can make you a carbon board don't fix carbon booms, though they are not novices in working with uni.

no big lump? you said it "may require high peel strength epoxy"
Never worked with that.
Did the booms you fixed require it?
We vacuumed ours. Would there be a different way that you suggest?
Do you know other shops with a long success record in repairing carbon boom spars?
What would you charge if we sent out booms from the store to repair them?
Back to top
View user's profile Send private message
bamer



Joined: 29 Oct 2014
Posts: 58

PostPosted: Wed Sep 04, 2013 1:57 am    Post subject: Reply with quote

keycocker, I will give you more information by PM. I don't want to outline the process in too much detail because I think the information in the wrong hands can be a bit dangerous: people fixing things that don't conform, not following directions, not doing the measuring/ math required.

But, I do believe it is a waste to put a $600 to $1,000 carbon boom in a landfill when it can be repaired for less than $50 in materials and two hours of labor. The only real price to be paid is a couple ounces, which for many booms is 'noise'.

To answer a few questions:
-No big lump. There is only a noticeable lump if the break is on an area of the boom body that overlaps the tail piece. Breakage in this area is rare from normal sailing, but I have seen it from shore pound. The repair gets tapered and the boom grip hides mild lumps well. You can even grind down the boom grip or splice in a thinner section if you want to to hide the bulge.

-High peel epoxy is generally only needed if you have a space constraint. Like if you are up against the front end, the tail adjuster, or nearing the tail piece overlap. But I like to use it anyway for at least the first bonding layer(s). This epoxy is just as easy to work with as what you use already, it just needs to be post cured. A space heater or wrapping the boom in a black garbage bag and sticking it in the sun will get the job done.

-Vacuuming is not required but is nice for removing excess resin and pulling things tight. A small bladder or balloon can also be used to exert pressure from the inside. I usually just use peel ply for the outside.

-A well known custom board builder has also fixed booms over the years and to my knowledge he has had every bit the same success.

-I don't really have the time to fix booms. But I will give you a detailed overview for free. I have charged in the past between $125 and $250 for the repairs. The $250 boom was a Formula boom broken in two places and I regripped the entire thing.

*The final product will depend a lot on attention to detail and your regripping skills.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    iWindsurf Community Forum Index -> Windsurfing Discussion All times are GMT - 5 Hours
Goto page Previous  1, 2, 3, 4, 5  Next
Page 3 of 5

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum

myiW | Weather | Community | Membership | Support | Log in
like us on facebook
© Copyright 1999-2007 WeatherFlow, Inc Contact Us Ad Marketplace

Powered by phpBB © 2001, 2005 phpBB Group