mast extension inside the mast

[joethewindsufa]

am more interested in this subject
than the one about using extenders and/or 30-40 cm extension ...
...
is it important to keep mast extension inside the mast to a minimum ??
there are 12, 28 and 48 mast extensions ...
if 10 cm extension is suggested for a sail, should one be using the 12 cm extension
rather than having more than 30 cm inside the mast ...
...
with that 30 cm inside the mast, does it impact mast curve ??
has anyone ever snapped a mast under those circumstances ??
since there are now carbon extensions - perhaps this is a selling point for them - they should be able to bend ...
thx
curious joe
nb someone once told me they felt it affected sail performance
back in the day of the MauiSails forums, Barry informed me that they always used the longest extensions ...
no matter how much went up inside the mast, but was interested in test results
too bad all that data just disappeared from the forum ...

[U2U2U2]

IMO carbon are more likely to break, alloy more likely to bend, but either only in extreme conditions.

The more I learn about masts, including extensions, the more I find I don't know.

Continue to fret over drivers who can't located turn signals

Yore reading pleasure here:

http://www.peterman.dk/windsurf-mast-article-gb01.htm

[coachg]

Placing a longer than needed extension does affect the bend, at least at the bottom. My 4.5 has a 400 luff & if I use a short extension it rigs fine but if I use a long or medium extension as I down haul the lines slip off the pulley track closest to the mast & bind because the bottom of the mast doesn't bend to match the downhaul line.

Coachg

[bred2shred]

You're really talking about splitting hairs here.

Yes, if you have a bunch of extension stuffed up the bottom of your mast, it is going to have a very slight impact on the mast curve (and add some un-needed weight). So ideally, you would use the shortest extension that will give you the overall luff length you need for your sail and provide a minimum of 6" engagement inside the mast. But the reality is most of us don't want to carry around three different length extensions when one (or maybe two) will do the job just fine. So if a long extension is all you have, then for sure use it without worry.

And no, I don't think having extra extension pushed up inside the mast is going to cause the mast to break. If you go the other way around, that would certainly be a problem - having too little extension engaged can cause the bottom of the mast to split.

sm

[manuel]

Well I'm afraid there's no yes/no type of answer unfortunately.

Light weights may prefer shorter/softer masts and may use a 370 instead of recommended 400 even on flextop sails.

More extension means harder top (the flex is moved up the sail), more grunt direct feel, less extension means flexier top, softer delivery of power.

In terms of durability long extensions aren't a problem unless sailing in a breaking wave environment where the leverage forces are more important.

I have snapped regular masts in the waves or simply pumping a 7.0 in light winds but never damaged an extension or a mast near its bottom.

[wynsurfer]

I've broken several masts too! In shorebreak. wave sailing and pumping. Never a break at the bottom where extension fits. almost always use a 30 cm. extension.

Once I ran over a Fiberspar World cup carbon mast at the base with my truck. It cracked the bottom 4" of the mast. Wrapped a few turns of fiberglass cloth and epoxy to repair. Still use it once in a while. I would npt worry about breaking a mast at the base.

[nw30]

I've seen several people split the bottom of their masts because they've added holes to their extension to make them longer, BAD IDEA. The holes stop where the minimum of the extension is to be inside the mast.

[U2U2U2]