Comments on: The 10-Step Carbon Extender

By: Nona

Nona — Tue, 12 Apr 2011 10:03:58 +0000

That’s way more clever than I was exepticng. Thanks!

By: Matt

Matt — Thu, 02 Dec 2010 17:41:32 +0000

yep, cheers Sean,

I think I am going to push it too far,
and even if for “non competition” sailing purpose,
I am going to search for a closer fit mast.

thanks again for your site and its load of info,

keep up the good work,

Matt

By: Sean OBrien

Sean OBrien — Wed, 24 Nov 2010 10:26:52 +0000

I would think the bottom!

Apparently Severne were doing tip-extendors at one point. I’ve never seen one in action but I would think the top section bend of a mast is most critical for the performance of a sail so tampering with the bend with extra sections worries me a bit.

I haven’t tried the Vapors with any shorter masts. I only really tried a variety of 550cm combinations. I would think the 520 would be a bit soft and spongy on the 11m and might flatten the sail too much in the bottom section.

Only way to find out is to try it though ;) Let us know how it goes.

By: Sean OBrien

Sean OBrien — Wed, 24 Nov 2010 10:17:41 +0000

Hmmmm, this is a tricky one Matt.

I put this question to some people involved with mast manufacturing in Italy. They confirmed that there is reinforcement around the boom area give or take 10cm either side of the boom opening.

They also suggested that every brand of mast will have different levels of reinforcement there (or none at all) and the length of the reinforced section will differ from brand to brand… *basically a “vague” answer at best!*

Therefore I couldn’t give you a definitive answer. With your mast out of the sail, just measure with the ‘brand recommended base setting and mast’ where the boom would join the mast and then measure where the boom would go if you used your 50cm extendor. If you’re boom is within a few cm of where it was going to be originally it should be ok. If it’s 20cm lower or higher or something I would worry.

If the recommended mast for this sail was a 520cm then you are only going to be 5cm or so different so I think this is ok. I’ve used plenty of NP sails with 46cm extension as standard so 50cm shouldn’t be toooo brutal (although it’s pushing it!) …

If the recommended mast is a 550cm, then I think you might be outside of the reinforcement area.

Sorry I can’t help more. I don’t really want to recommend you to try it and then break your mast!!! But then it could work perfectly also… I’m just erring on the side of ‘caution’. ;)

By: Matt

Matt — Mon, 22 Nov 2010 08:09:52 +0000

Hi Sean,

quite question/comment – you mentioned earlier that using an extension may position your wishbone in an area where the mast is no longer “re-inforced”, for instance, I want to use a 510cm + 50cm on a 560cm sail… how bad is this?

I am trying to understand the rule of thumb and when not to bother with a fixed mast extension,

Matt (FR)

By: erik

erik — Wed, 11 Aug 2010 22:29:33 +0000

Hi, great article. but I was able to do it even simpler, without step 7, so no carbon etc needed.
Had an old ck35 mast, which is heavily reinforces at the boom area with glass fiber. (and broken above that ;-)
I cut the bottom part first fresh (1cm off) to get a good rimm. Then 55cm, length of my extender I needed, and turned it upside down. My old arrow base (0cm extension) fits really snug at that side.
Then searched the right portion of the mast to make the spigot. (with the to use mast, slight it in, tappered side, mark a few cm extra) Just sandpapered (ok with the sandpaper machine ;-) this a bit and have a perfect fit for the mast bottom.
Then simply machine sandpapered the other end of the spigot until it fitted really tight in my extender.
Remember, this is the outside reinforced section, so only getting ridd of glass, not the carbon structure. Still thicker than the mast piece I put it in.
Put some 2 component epoxy glue on the spigot and hamered it lightly down its spot.
Finished!

By: michelb

michelb — Fri, 29 Jan 2010 02:41:51 +0000

Hello,
DO you think is better extend 20 cm from the bottom or from the top of the sail?
I have a 520 Gaastra 100 mast that I want to use in a 11mts vapor 2008 but still need some extra extension…..

Any tip ( you was using Vapors and knowing you a little for sure you test other combinations than writed on the packs…)

By: Sean OBrien

Sean OBrien — Tue, 12 Jan 2010 03:26:18 +0000

We’ve built them to 50cm before and then used 5-10cm of extension on top of that. Although its possible to build one larger than 50cm, I think it would be safer to build one at 45-50cm and then use your normal extension to get the extra 5-10cm.

If using some extension inside your home-made extendor, make sure you have a good 15-20cm of extension still inside the extendor, otherwise you might cause it to fail with the large forces on only a small section of the extension.

By: TG

TG — Mon, 11 Jan 2010 20:05:25 +0000

Question: how many cm do you feel comfortable building these to ? 50 cm? And do you add some extension on top of that ?

By: Sean OBrien

Sean OBrien — Tue, 08 Dec 2009 10:05:13 +0000

Hi Ralph,

While it would be ‘possible’ to rig a larger sail on a 490cm you run in to two problems.

Firstly, the boom would be a lot lower than normal in a section that isn’t really reinforced so you might run the risk of breaking your mast at the boom attachment.

Secondly, the bend curve of your mast will be really wrong as you’ll have a very stiff bottom section with the extra base… it might work to ‘get out on the water’, but the early planing, handling, performance and stability of the sail will be severely compromised.

You’d be better off finding a cheaper sail so you can get the correct mast for the sail if you can.