Mainsail in boom furling vs. in mast furling

[Dockhead]

Originally Posted by Paul Elliott

Hardly. Boom-furling also gives you:

• Effective full-length battens
• Roach (more sail area, better lift/drag performance)
• Lower center of gravity when furled

So make your choice and be happy with it.

Indeed, but how do you shape the foot of the sail? I've never tried in-boom furling, so this is a purely arm chair and possibly ignorant question, but you've got no outhaul, right?

[boatman61]

Originally Posted by Dockhead

Indeed, but how do you shape the foot of the sail? I've never tried in-boom furling, so this is a purely arm chair and possibly ignorant question, but you've got no outhaul, right?

I was always unhappy with the sail shape on a reefed boom furler.. whereas the in mast could be adjusted to the correct tensions to stop that annoying flutter at the roach..
But someone will likely say I was not furling it right.
I think either are a worthwhile investment for those silly Cats like the flybridge deck Lagoons where you need a ladder to work effectively on the sail.
Have never owned either but delivered both types so can understand someone who has a boat fitted with either will defend what they have.. till after its sold..
Slab is my choice every time..

[double u]

the probs of those 2 sailtainers on our base were manifold (apart from the absolutely-unacceptable-having-to-hold-the-boat-into-the-wind idiocy):
1. those heavy retrofitted booms overstrained the mainsheet-system: the very smallest slack & a little jerk of the boat & the car was a goner
2. if the angle between mast & boom was not just so, & this means 100% right to the degree, then the sail would either bunch up at the mast (boomend too low) or tear of it's rather fragile lufftape. The "headboardslide" - a 6 or so mm thin stainless "slug" sewn on with thin webbing - didn't look confidence instilling.
"thin-&-delicate" btw being the watchword of the whole sail.
as far as I can remember there wasn't as single advantage over a jiffy reef apart from being able to reduce sail variably & not in fixed steps. seemed hardly worth anything let alone the sums those sailtainers cost. were a pita to explain to the customers at check-ins.
as it also came up:
we had also in the fleet
2 Bamar retrofit-behind-the-mast furlers (GibSea 442) &
4 or so Topreff behind-the-mast units (Feeling 416 & 446)
both dreadfully ugly looking contraptions, the Topreff even more so, but apart from one occasion, when they managed to really tangle the main inside one of the Bamar-things (took me 2 hours in the bosunschair to undo their to-&-fro-folding of the main) they gave no trouble in the three years I worked on the base
on the Bamar too the main had to be fairly delicate without big tablings.

[Paul Elliott]

Originally Posted by Dockhead

Indeed, but how do you shape the foot of the sail? I've never tried in-boom furling, so this is a purely arm chair and possibly ignorant question, but you've got no outhaul, right?

The Leisurefurl does not have an outhaul, but we can still shape the foot effectively. The main is cut so it has a full belly when the sail is fully unfurled. This gives a very good light-air shape for a reach or run.

But the main is only attached to the furling roller by a boltrope on the middle third of the foot, and at the tack and clew via lashings. To flatten the sail I take a partial turn on the furler. As the roller turns the slack in the foot is rolled in, and the tack and clew are stretched out similarly to tensioning an outhaul.

By the time we have a full turn on the furler, the belly is flat and the tack and clew begin rolling up on the roller. The extra bulk in the middle of the furling roller and the full-length battens maintain a flat sail shape as the main is further reefed.

I'm sure that a sail-shape purist would want more tweakability, but the system works surprisingly well.

[Locquatious]

Originally Posted by Dockhead

Indeed, but how do you shape the foot of the sail? I've never tried in-boom furling, so this is a purely arm chair and possibly ignorant question, but you've got no outhaul, right?

We have the Schaefer boom furl and have no problem with sail shape or fluttering. As I recall, the last foot or so of the sail is not held in by a bolt rope. But the foot is tied back tightly to the end of the drum. When the sail is raised, that tie-back becomes even tighter as it angles up to the loose foot.

When the sail is reefed, I'm not really that concerned about sail shape. Even still, when reefed our sail looks fine.

[Dockhead]

Originally Posted by Locquatious

...
When the sail is reefed, I'm not really that concerned about sail shape.. .

You would probably feel differently about that if you sailed in windy latitudes as I do. I am very concerned about sail shape, reefed or not, and one shape does not suit all conditions.

[Dockhead]

Originally Posted by Paul Elliott

The Leisurefurl does not have an outhaul, but we can still shape the foot effectively. The main is cut so it has a full belly when the sail is fully unfurled. This gives a very good light-air shape for a reach or run.

But the main is only attached to the furling roller by a boltrope on the middle third of the foot, and at the tack and clew via lashings. To flatten the sail I take a partial turn on the furler. As the roller turns the slack in the foot is rolled in, and the tack and clew are stretched out similarly to tensioning an outhaul.

By the time we have a full turn on the furler, the belly is flat and the tack and clew begin rolling up on the roller. The extra bulk in the middle of the furling roller and the full-length battens maintain a flat sail shape as the main is further reefed.

I'm sure that a sail-shape purist would want more tweakability, but the system works surprisingly well.

Thanks ; now I understand it better. So you get a kind of "flattening reef" when the sail is unreefed? But after that, you only get one foot tension setting? Presumably that's adjustable at the dock at least?

[Paul Elliott]

Originally Posted by Dockhead

Thanks ; now I understand it better. So you get a kind of "flattening reef" when the sail is unreefed? But after that, you only get one foot tension setting? Presumably that's adjustable at the dock at least?

With zero turns on the drum (or mandrel) we get a very full sailshape. A quarter turn of the mandrel begins to flatten the foot as it tensions the tack, foot, and clew. A half-turn gives more tension. With one full turn on the drum we have a nice flat main. We can also vary the main shape with the halyard tension and boom vang. Our hydraulic backstay adjuster tweaks the main a little too, but since we don't have a fractional rig, this is mainly for headsail shape.

So we have some fine-tuning control. I can't claim that I fuss with these too much, I'm pretty easy to please most of the time.

[jtsailjt]

Originally Posted by goat

I know in theory the wind shadow of the mast will hurt performance, but does
anyone have real life experience, good or bad, with behind the mast furlers?

My boat had the Profurl behind the mast furling system when I bought it 4 years ago and in my mind it was going to be one of the first things to go because my previous boats had slab reefing and I really enjoy trying to trim a well shaped sail properly. But the previous owner had recently bought a very nice and pretty expensive laminated furling mainsail so I thought I’d give the furler a try before removing it. I had a few jams when unfurling at first (avoided by tight furls and being on port tack when unfurling) and there’s no doubt that lack of roach negatively impacts windward performance, but I’ve grown to really appreciate its simplicity and ease of reefing so am no longer in such a big hurry to remove it. Profurl no longer makes or supports the system but many of its parts are in common with their jib furlers so most parts are available. In order to prevent the luff foil from sagging to leeward, there are 5 hinged “claws” on the back of the mast that are sort of ugly but as long as it keeps working well and the sail is in good shape, I will keep it. But, because it’s no longer supported by Profurl and nothing lasts forever, when the sail goes in a few years, I’ll remove it and replace it with a roachy full batten hanked on sail.

Other than the way it looks and the lack of roach, I like it. I’ve never had a jam I couldn’t clear from the deck but if I did, I’m sure that I could clear it from a bosuns chair because, unlike with inmast systems, you have access to the sail when furled.

We have one electric winch on the cabin top which we use on both the furling line and the outhaul and IMO thats a really important part because it allows a singlehander to easily furl in strong winds. It would be difficult for a singlehander to operate a manual winch while keeping the proper amount of tension on the outhaul or furling line.

[double u]

the Topreff system was very much alike those "claws" were a bit different. as said it worked well enough, it's look robbed the boats of the last vestiges of "romance of sailing" though

[mitgroup]

We have the LeisureFurl in-boom system and are very happy with it. The key is the boom to mast angle. Forespar tells us that this angle needs to be 87 degrees. We have marked the topping lift with a whipping at that angle. With this in mind it works well. We have tried to reef while sailing and it doesn't work well. What I REALLY like about the LeisureFurl system is that my wife and I can deploy and retrieve without leaving the cockpit.