So walk me through the in-mast furling mainsail

[Na Mara]

Unfortunately my main is getting on a bit and will probably have to be replaced soon. This year I couldn’t get it to go into the mast without little crinkles as the belly of the sail went in. Nothing that could cause a jam but a sure sign that the sail is getting too full for the in mast system. Having to replace the main twice as often is one of the bigger disadvantages of in mast reefing.

[Dockhead]

Originally Posted by Na Mara

. . . Having to replace the main twice as often is one of the bigger disadvantages of in mast reefing.

No, half as often. Mainsail lasts much longer being rolled up inside the mast.


Unless you consider "lasting", in the case of normal battened mainsails, to include that stage where they're already stretched out and useless upwind.


In any case, use laminate for in-mast furling mains. It works much better and keeps its shape until the end of its life. And so much better sailing too.

[Na Mara]

No I mean lasting as in sea miles. Both mains will stretch similarly but the slab reefing system tolerates this more.

Also battened mains in proper boom covers are just as well protected as in mast systems inside masts in my experience.

[donradcliffe]

I have used all kinds of mainsail systems--in mast, in boom, dutchman, stack pack. Just finished a 2400 mile delivery from Kauai to Santa Cruz, mostly to weather on a 42 ft boat with in mast furling. We had a lot of problems unfurling in lighter winds, with folds in the sail jamming in the slot. Things got better in bigger breeze, as the shaking sail sorted itself out better than we could.

There was a huge performance hit on the wind. Compared to other systems, the main had less area, less shape, and the maximum draft was back at the leach. Fortunately the boat had a pretty good looking genoa, otherwise I'd still be out there.

If it was my boat it would have a dutchman system, no bow thruster, and some sea berths, but hey, its a "modern" boat.

[Lucid]

My second boat with one. They are awesome simple and I think safer. The wind pipes up roll in the amount of sail you want, no climbing around etc. and when the squall passes roll out and keep on trucking. Before I went to in mast I read a lot of the same comments on how bad they are etc. this has not been my experience nor that of anyone I know.

[Wilyum]

Originally Posted by donradcliffe

no bow thruster, and some sea berths, but hey, its a "modern" boat.

Why no bow thruster?

[chrisr]

something which has just come up on board icw our in-mast furling might be of general interest

our in-mast main furls via IN & OUT push buttons on the helm panel. each buttons has a rubber boot to keep out water eg when washing down or such.

the owner often does the furling of the mainsail via these push buttons and just today i noticed that her finger nails had split both boots, effectively allowing water in.

potentially disastrous !

i've repaired by gluing a new bit of rubber over the splits, but thought it worth mentioning

perhaps fingernails are not terribly common amongst sailing ladies, but rubber button boots are all around us. it pays to check !

cheers,

[Dockhead]

Originally Posted by Na Mara

No I mean lasting as in sea miles. Both mains will stretch similarly but the slab reefing system tolerates this more.

Also battened mains in proper boom covers are just as well protected as in mast systems inside masts in my experience.

Well, that was my point. If you like to sail thousands of miles on blown-out sails, then in-mast furling is not for you for sure, because the system doesn't tolerant stretched out sails. In fact, woven sails are altogether sub-optimal for in-mast furling. Laminate sails, which don't stretch at all, are what you want.



Yes, sails stretch the same regardless of furling system, but in-mast furling sails, being rolled up and completely protected, do last longer in terms of creasing, chafing, and UV damage. Boom cover will help with UV but not with the wear which occurs from creasing. And who covers the flaked mainsail within seconds of dropping it, every single time? I sure didn't when I used that system.

[Joli]

Everything is a compromise but giving up performance by using in mast furling isn't something we're ready to do.
The shortcomings for us are:
1) the sail needs to be fairly flat to furl so you give up power.
2) sail area is lost with a hollow leech
3) because of the internal mechanisms the ability to bow the mast is greatly minimized, you can't depower the main.
4) lots of extra weight up high

It would be disappointing in light air to not be able to sag the rig and power up.

Plus, the effort of horsing around a big main is good for us. I think the misses calls for reefs in and out just to keep my beer gut somewhat in check.

[Dockhead]

Originally Posted by Joli

Everything is a compromise but giving up performance by using in mast furling isn't something we're ready to do.
The shortcomings for us are:
1) the sail needs to be fairly flat to furl so you give up power.
2) sail area is lost with a hollow leech
3) because of the internal mechanisms the ability to bow the mast is greatly minimized, you can't depower the main.
4) lots of extra weight up high

It would be disappointing in light air to not be able to sag the rig and power up.

Plus, the effort of horsing around a big main is good for us. I think the misses calls for reefs in and out just to keep my beer gut somewhat in check.

Those are all about right, and for moderate latitudes and coastal sailing in good weather I also wouldn't want in-mast furling.

The performance hit however is not as bad as you might think if you use a laminate sail with straight leech or slight roach and vertical battens. We race with in-mast furling (and laminate sail) and are surprisingly competitive, regularly stomping higher rated but smaller boats, especially over long distances. Performance advantages of in-mast furling include very quick control of sail area, and the somewhat flatter sail is better in strong wind and is good upwind. We depower by hardening outhaul and vang and flattening the sail, or just quickly removing some sail area. I do miss the backstay as a control, but not all that much.

With hollow leech and battenless woven sail, the performance hit is much greater. Hollow leech gives a really bad shape, and I guess a lot of people who hate in-mast furling have not experienced battened in-mast sails. It's pretty much night and day.

In really light summer weather I sometimes miss the roachy full batten mainsail, but not all that much. And I certainly don't miss the constant tangle between battens and lazy jacks.

[Pete7]

Originally Posted by Joli

Everything is a compromise but giving up performance by using in mast furling isn't something we're ready to do.
The shortcomings for us are:
1) the sail needs to be fairly flat to furl so you give up power.
2) sail area is lost with a hollow leech
3) because of the internal mechanisms the ability to bow the mast is greatly minimized, you can't depower the main.
4) lots of extra weight up high

It would be disappointing in light air to not be able to sag the rig and power up.

Plus, the effort of horsing around a big main is good for us. I think the misses calls for reefs in and out just to keep my beer gut somewhat in check.

1. Surely that depends on the yacht. Modern 7/8th rig perhaps but we have a masthead rig and small main. The Genoa does the real work.

2. A little yes but see note 1.

3. True, but how many actually bow the mast in cruising role. How about sticking a small reef in. 30 second job from the cockpit.

4. Weight accounted for during the design and build.

If you want to race around the cans on Sunday mornings, then a fractional rig, really deep keel and laminate sails. Want to go cruising whether the weekend or the summer with a stress free system easy to operate by one person, well you have a choice. Note the number of new yachts being fitted with in mast reefing.

I hadn't used in mast before buying our yacht, so asked the previous owner to really demonstrate it during the test sail. He did and and my comment was "is that all there is too it?" "I would like to buy your boat please"

[Joli]

As mentioned earlier, everything is a compromise so you have to pick what works best for you. I completely understand the convenience of in mast furling, many friends are very happy with theirs but coming from a racing background it doesn't work for us. We don't want the performance hit.

We're happy to have a traditional main with slab reefing. It's not a burden to reef or shake them out without electric winches, it takes about a minute to reef. The rig is 93', the main is Dyneema, it weighs about 250#'s, the halyard is 2 to 1 and the luff is supported by Batt Cars. The best thing we ever did was adding hay racks to the boom to support the cloth when reefing or dropping the main.

Here is our two year old main with about 15,000 miles on it, some were very hard miles. We hope to get 25,000 miles from the sail. We have very good sail control with a hydraulic backstay and vang, runners/checks and a 400 to 1 mainsheet. To offer perspective, while in St Martin my wife changed out the main halyard. It required a trip to the top, it's pinned in the truck since it's 2 to 1.

Sorry about the picture of the main being sideways, I don't know how to fix that?

[Dockhead]

Originally Posted by Joli

As mentioned earlier, everything is a compromise so you have to pick what works best for you. I completely understand the convenience of in mast furling, many friends are very happy with theirs but coming from a racing background it doesn't work for us. We don't want the performance hit.

We're happy to have a traditional main with slab reefing. It's not a burden to reef or shake them out without electric winches, it takes about a minute to reef. The rig is 93', the main is Dyneema, it weighs about 250#'s, the halyard is 2 to 1 and the luff is supported by Batt Cars. The best thing we ever did was adding hay racks to the boom to support the cloth when reefing or dropping the main.

Here is our two year old main with about 15,000 miles on it, some were very hard miles. We hope to get 25,000 miles from the sail. We have very good sail control with a hydraulic backstay and vang, runners/checks and a 400 to 1 mainsheet. To offer perspective, while in St Martin my wife changed out the main halyard. It required a trip to the top, it's pinned in the truck since it's 2 to 1.

Sorry about the picture of the main being sideways, I don't know how to fix that?

Wow, that's a beautiful rig, and beautiful sail!



93'! What kind of boat is that?

[Joli]

Originally Posted by Dockhead

Wow, that's a beautiful rig, and beautiful sail!



93'! What kind of boat is that?

Thank you, that is very kind of you to say.

It's a 1974 C&C 61 with a tall rig. We like the boat a lot but understand it isn't a modern cruising boat, it's an old race boat with a whole lotta miles on it. We've owned the boat for about 20 years and cruise it between the Caribbean and the East Coast, prior to that we were in the Great Lakes. We are looking forward to visiting parts of Europe when the whole covid thing is under control. Here is a picture from St John with us in the foreground, then Eros then Columbia in the background.

[DMF Sailing]

Originally Posted by Joli

Thank you, that is very kind of you to say.

It's a 1974 C&C 61 with a tall rig. We like the boat a lot but understand it isn't a modern cruising boat, it's an old race boat with a whole lotta miles on it. We've owned the boat for about 20 years and cruise it between the Caribbean and the East Coast, prior to that we were in the Great Lakes. We are looking forward to visiting parts of Europe when the whole covid thing is under control. Here is a picture from St John with us in the foreground, then Eros then Columbia in the background.

That's one hell of a nice boat.

I've sailed smaller C&Cs (34 and 38 sloops). Loved the way they handled.