New sail, thiught this was intresting....

[joes new addiction]

New sail, thought this was intresting....

I'm refitting my '71 PT 1/4, and the sails are the orginal.
Although they are in so/so shape, they are far from white and "chrisp".
I called "Super Sailmakers" outta Fla and got a quote for a main sail, (it's my first time for this so I had them "hold my hand" through the process. I dunno if I got a good deal er not, but, I'm happy with it).
Got the new white crisp sail back and noticed there isn't a line or slugs or???? to slip into the boom track to hold the sail in place.
"Great my first time doing this and they forgot or more than likely I screwed up that that part"!
Emailed them over the New Years week and they got back to me.
The new sails don't "hold fast" to the boom, just at the foot and the leach. This way the sail fills and you get a better form of the sail.
I got to thinking about it and you know it makes pretty good sense!
Maybe this is common knowledge, but all the sails I've seen on the boats I've observed were the "old fashion way".
I'll have to try both sails and report the difference!
Joe
See you can teach a new sailor new tricks!

 

[berner73]

It's referred to as a loose footed main.

Loose Footed Mains - by Bill Colombo (Doyle Sails)

I tend to recommend loose footed mainsails in most cases. There are a couple of reasons for this. Since the loose foot is a simpler setup it is easier to trim. By tensioning the outhaul the foot of the sail is able to be pulled absolutely flat. On mains with an attached foot, there is usually some 3D curvature designed into the foot of the sail so that it can have a reasonable shape just above the boom but still return to the straight line of the boom groove or track. Pulling the foot tight will minimize, but not totally eliminate this 3D curvature. This is the reason that in the old days racing mains used a flattening reef, which tensioned the sail on a line just above the foot curvature(these days amost 100% of racing mains are looe footed). Conversely, when you want to make the main fuller and more powerful there is no limitation as to how full the loose footed main can get, since there is no cloth holding it to the boom centerline. As you mentioned a loose foot mainsail is easier to bend on to the boom. It also affords much more flexibility when rigging such thing as, reef lines, jibe preventers, vangs and other things that require tying a line around the middle section of the boom. I would suggest you try one of these mainsails. Most people never go back.

 

[Scott T-Bird]

Loose-footed main ...

That's what you have. To sort your terminology out correctly, your foot is the entire length of the bottom of the sail. Your foot is attached at the tack with a pin (where the boom meets the mast with a gooseneck) and at the clew, with a slug, which can more easily slide within the sail track of the boom.

Sailmakers should ask if you want a loose-footed main or a bolt rope for the more traditional way of attaching foot to boom. Maybe they did but you didn't understand the question.

Anyway, I prefered the loose-footed main as you can see in the photo. I like it because I can see the shape more readily when adjusting outhaul, which I like to do. The traditional sail with a bolt rope tends to develop a shelf at the foot of the main which I think affects the sail shape and makes outhaul adjustment more difficult when the bolt rope tends to snag in the track or slide less easily.

You did good, now just wait for Spring!

 

[wflowe2]

All boats with in-mast furling have loose footed mains. As you can tell by the popularity of in-mast furling (it's now standard on many new production boats) the loose foot must work pretty well. Folks who are serious racers hate in-mast furling but I don't think it's because of the loose footed maim.

 

[Joe]

The traditional sail with a bolt rope tends to develop a shelf at the foot of the main which I think affects the sail shape and makes outhaul adjustment more difficult when the bolt rope tends to snag in the track or slide less easily.

Hope you don't mind my nitpicking your post, Scott. But, the "shelf" that you mentioned is not a "development" of the foot's bolt rope. A "foot shelf" (or shelf foot) is an added section of light weight material sewn into the foot of the sail. It allows that lowest section to expand draft depth when the outhaul is eased. When the outhaul is tensioned the shelf's extra material folds in and lays against the boom.

Many sailmakers still offer the shelf foot option, at an additional fee, of course. The following quote is from UK Sailmaker's:

Shelf Foot and Loose Foot

The Shelf-Foot and Loose-Foot constructions are options that allow the addition of a substantial degree of extra fullness in the lower portion of the mainsail, in order to improve racing performance on reaches and runs. In very light air, the improved performance is achieved even to windward.

The extra fullness is removed by tightening the outhaul. When the outhaul is eased, the sail maintains an airfoil shape down to the boom.

With the Shelf-Foot option, a light piece of material connects the sail to the boom. With the outhaul eased, the connecting material unfolds and forms a shelf between the bottom of the main and the boom. When the outhaul is pulled tight, the shelf closes up and lays against the side of the boom.

Loose-Foot construction does away with the shelf material. The sail is only attached to the boom at the tack and clew. This attachment method is just as strong as the attachment of the foot to the boom.

Many boats are switching to Loose-Footed mainsails because they are easier to bend on and to remove from the boom. They are also less expensive.

 

[Gunni]

Hope you don't mind my nitpicking your post, Scott. But, the "shelf" that you mentioned is not a "development" of the foot's bolt rope. A "foot shelf" (or shelf foot) is an added section of light weight material sewn into the foot of the sail. It allows that lowest section to expand draft depth when the outhaul is eased. When the outhaul is tensioned the shelf's extra material folds in and lays against the boom.

Many sailmakers still offer the shelf foot option, at an additional fee, of course.

I sailed a J-40 for years with an attached foot shelf. That boat was a light wind demon. Loosen the outhaul, inflate the shelf and you could feel the acceleration. Perfect fat draft in the foot and lower section of the sail. Miss that.

 

[Jackdaw]

All boats with in-mast furling have loose footed mains. As you can tell by the popularity of in-mast furling (it's now standard on many new production boats) the loose foot must work pretty well. Folks who are serious racers hate in-mast furling but I don't think it's because of the loose footed maim.

You are right; It's not because of the loose footed main; in fact the vast majority of racing mains are loose footed. Racers have several issues with rolling furling mains however, the biggest being the major reduction of possible sail area a main must have in order to furl. This is because the main must be 'negative roach', meaning the the roach is at best straight or more typically cut inwards to allow the sail to roll, and make up for lack of horizontal battens. A racing sail's roach will be curved outwards, adding perhaps 15% extra sail area.

There are other reasons as well.

 

[kenn]

Our main has a bolt-rope, but on the advice of a fellow-owner I have been rigging it loose-footed for a few seasons now, and prefer it. It seems easier to get the bottom shaped nicely, and of course less drag on the outhaul.

 

[rardiH36]

So is it worth experimenting "loose footed" for me by sliding out all of my mainsail foot slugs from the boom track and just leave in the aft-most slug which is just a few inches forward the clew? (Its is a beefed up bronze slug rather than the marlon type.) For this, I expect there will be a lot of friction on the one slide, so out haul adjustment might be difficult. So should I slide out all the slugs -- and leave the only clew attachment being the out haul line leading to the end of the boom? Or since the sail was cut for foot slides, the experiment won't have a basis for success? When I reef, its essentially a loose footed outcome. But of course, I can't really adjust the out haul tension.



rardi

 

[Scott T-Bird]

rardi, you definitely don't want to slide out all slugs and merely attach with just the outhaul. The sail needs to be attached to the boom and the outhaul doesn't do that, especially when you ease the outhaul.

I also think that your end slug needs to be attached to the clew for your experiment to be effective. Mine is a maralon slug, but friction doesn't seem to be a problem. Your sail is probably cut with consideration that the entire foot is attached, so I wouldn't bother reinventing ...

 

[rardiH36]

Hi T-Bird:

Thanks for your insights about my proposed experiment. You make good sense.

The aft-most boom slug I have actually essentially is the clew. So I should be safe in that respect.

Another consideration I thought of since my post about my specific configuration was the possible imbalance stresses on the boom caused by experimenting with "loose footed" in respect of my existing mid boom sheeting setup.

I need to really see the light of lots of foot slugs vs. a loose-footed mainsail arrangement -- for an already foot slug configured main sail!

Not exactly now, but in a day or two, I think I might stir things up by migrating the topic over to Don Guillette's sail trim forum.

rardi