Hobie 18SX mainsail size

Hello,
Just picked up a 91 18SX. When I got it the prev owner was telling me that he added a small line to the top of the sail to pull it down toward the boom. He said it just seemed to far from the boom. It looks like there is another foot of mast over the top of the sail. I am thinking it is not an SX sail. It is a vertical cut mylar but not sure if they mad those for the non-SX 18. Here is a pic from his post. Thoughts? file:///Users/patrickmcmonigle/Downloads/hobie18SX.pdf

The link appears to be a local file location on your PC. Files and images need to be in publicly accessible sites.

SX sails were Mylar/Dacron and vertical cut.

_________________
Matt Miller
Former - Director of Parts and Accessory Sales
Warranty and Technical Support
Hobie Cat USA
(Retired 11/7/2022)

Mine is the type square cut at the top. Luff measures 8 meters or 26'3" if that helps identify it. Not sure how to post a pic on this format.

Not sure about the specific luff length measurement for the 18 main, but for reference, a standard mast is 28’ long. The SX mast is about 29’-6”. So it sounds like themainsail you have is an aftermarket, sized for a standard 18, not the SX. Hobie never made any square top sails for the 18.

Using the pigtail at the top of the mast could make it more difficult to hook and release the halyard ring from the mast hook, since the ring won’t be stabilized by the sail. You also rin the risk of the bolt rope pulling out of the plastic comptip lufftrack.

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The pigtail does not interfere with the halyard ring as it is between the sail and the ring. It just positions the top of the sail around 5 inches lower. Not sure how far off the bottom of the luff should be from the boom. That would help. Previous owner just thought it was too high. I think I would rather remove the pigtail and have the mainsail all the way up. Just need to get a feel for how big the gap between the boom and sail bottom should be. I searched pics and there seems to be a wide range.

The mainsail tack is generally about 3-6” above the gooseneck fitting with moderate downhaul tension applied. Definitely should be at least a few inches below the cutout in the mast track.

If you are using a square head aftermarket mainsail, it is very possible that you (or the previous owner) simply aren’t adding enough downhaul. Hard to know for sure when aftermarket sails are being used. At the very least, make sure you’re pulling on enough downhaul that all wrinkles are being pulled out of the luff.

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Thank you, I will raise it up and see how tight I can get it. Seems strange that there is no listed luff length though. I suppose that is would be hard to measure without tension on it.

Chip at Whirlwind made square top sails for the H18.

However, the design of the H18 does not lend itself well to square tops -
To get a tight leech, we ended up having to do weird things:
1. Rotate the mast fully, which would allow the mast to 'bend'
2. Maximum downhaul
3. Sheet in tight.

I miss my old SX18...

_________________
2015 H16, with spin,
SOLD 1989 Hobie SX18 Sail # 1947 "In Theory..."
'Only two things are infinite, the universe, and human stupidity. But I'm not sure about the former.'

Having removed the pigtail that the previous owner put on the head, I raised the main again and with max downhaul I was able to get the tack just level with the bottom of the track cut out. I think I am just going to go with it. With the pigtail it just looked like the sail was reefed.