Loose Footed Main OK?

[Moonchaser2304]

Hi everyone!

I'm a newbie to this forum and looking forward to reading all the collective wisdom here on many topics. I saw one other similar post but it was a different slant.

My question today is if loose footing a mainsail is OK, and if so, should I have the boltrope and "shelf" cut off?

Here's why I ask:
I want to use the boom slot for the slugs/boltrope for a "leave-on-boom" sail cover (that will be a separate post).

I have a Catalina 30 with a stock Catalina-type (made by local sailmaker) mainsail with a boltrope across the foot. My outhaul works fine and could easily work with a loose footed main.

I have heard from a couple of well respected sail makers that loose footing a main is perfectly fine, and indeed is recommended in many applications like race boats but what are your thoughts about that on a Catalina 30?

I've also heard about the concern of compression loading on the boom but I'm not sure I understand why you'd necessarily need more tension on the outhaul just because the main is loose footed..your thoughts?

I looked at the shape of my main under wind load on a sail the other day and there is no load on the bottom 6" (or so) of the main, tapering out to tack and clew to 0" so to my untrained eye in this aspect it does not appear like the boom is providing any down tensioning on the sail, so my thought is that cutting off the shelf would not hurt from aerodynamic sense, but is there some other benefit in having the shelf in the main I may be missing?

OH..I should say...I sail on an inland lake and am more of an "evening cocktail" cruiser than a racer and if loose 1/10 of a knot for any reason that's not a concern.

Thanks in advance for any advice you have..looking forward to your thoughts!!

[GordMay]

You might find an earlier* discussion, “Loose footed main sails”, interesting & informative:
Goto: http://www.cruisersforum.com/forums/...sails-274.html

* Ran from 2003 thru 2006

[Ex-Calif]

Originally Posted by GordMay

<snip> an earlier* discussion, “Loose footed main sails”, <snip>

* Ran from 2003 thru 2006

Sounds like it was tough to draw out differing opinions - LOL

[rtbates]

I had my main re-cut and made loose footed and it works great. Boat is a full keel Cape Dory 25D.

[svTOTEM]

A loose footed mainsail is just fine for racing or cruising; and boats of any size. I assume you have a crosscut mainsail. Have the existing shelf foot and bolt rope removed. A proper loose foot has a positive curve to increase sail area going downwind; roughly 5” for your size mainsail. Then the foot has a Dacron cap sewn on with foot line and cleat at the tack to adjust the tension.

Removing the shelf foot takes away the endplate effect when the outhaul is slackened while sailing downwind. This will have no bearing on the performance of your boat. Conversely, the loose foot usually makes the lower 1/3 of the mainsail smoother (no wrinkles coming from slugs/slide/boltrope). If you do not have lazy jacks, a loose footed mainsail is harder keep on the boom when down.

As for boom and outhaul loading there should be no real difference whether loose footed or not. In fact a poorly built main with attached foot can transfer a lot of off axis loading onto the boom, in a way that neither the sailcloth nor boom like so much. It’s a good idea to have an outhaul track/car with a loose footed sail. Without it, the mainsail clew sets slightly to leeward; causing wear on the outhaul and sheave.

[W32PAMELA]

I've noticed that when cruising in the company of several boats, some with attached mains and some with loose foots, that in situations requiring motorsailing very close to the wind, the boats with loose footed mains tend to take them down because of flogging. The boats I've observed have all had in-mast furling.

Being able to keep the main up greatly increases the stability and comfort of the boat. I don't know if this offsets the benefits but IMO if you are planning on doing something like the thorny path it is something to consider.

Bob

[svTOTEM]

It makes sense that inmast furling mainsails flog more in that situation. It's not a function of the loose foot, but rather no battens to dampen the flogging.

[SkiprJohn]

My only concern with loose footing the main is mid-boom sheeting that might cause higher stress loads nearer the center of the boom with no counter force from the main.

Kind Regards,

JohnL

[delmarrey]

Originally Posted by svTOTEM

It’s a good idea to have an outhaul track/car with a loose footed sail. Without it, the mainsail clew sets slightly to leeward; causing wear on the outhaul and sheave.

This exactly what I have done!

I have two main outhauls. The sail = 380 sq. ft. The outhaul on the clew is in the boom w/5:1 purchase, actully 6:1, I have a clew block sewn in. The one on the car just runs over a block, then forward under the boom to a cam cleat.

Up wind I pull the car all the way back & cleat it in. Then use the purchase to straighten out the main for trim.

Down wind I do not let the boom out more then 60º but ease off on the car halyard and then off on the purchase. The car goes forward and the main acts more like a genoa on a pole that is adjustable by hauling in or letting out the car. Depending on the angle of the wind I can maximize the catch.

I do have lazy jacks now but a basket works too. The only down fall, literally, is you do need a topping lift or lazy jacks to keep the boom from "BOOM".

The boat actully gained 1.5 kt of speed after installing a new loose footed mainsail.

I'll get pictures this weekend................................_/)

[FrankZ]

Originally Posted by delmarrey

The boat actully gained 1.5 kt of speed after installing a new loose footed mainsail.

Is this because of the loose foot or the new sail. My boat sailed much better when I got a new loose footed sail as well.. though new was probably more of it than loose footed.

[svTOTEM]

Mid boom sheeting and/or a vang put a lot of load mid boom. A boom is, or at least should be, designed to tolerate those loads plus a healthy margin of error on its own. The foot of the mainsail doesn't provide any significant counterforce to that.

Consider that on a crosscut main, any loading perpendicular to the boom is on the sailcloth bias. This is the weakest and stretchiest orientation of the sailcloth. The reason is simply that sails are not designed with the intention of offsetting mid boom downward forces. One last note is that many mainsails with an “attached foot” have a “shelf” or “lens” foot to improve the sail shape going downwind. A shelf foot is made from 3 oz sailcloth (give or take) and would easily shred if loaded.

[forsailbyowner]

Ive been reading a book on sail trim and t had an article on mainsail trim stating the shelf is for sailing upwind in light air.

I made a big mistake one time of putting a vang on a hunter with in mast furling that we were chartering, We were sailing downwind in large rolling seas and the helm was difficult. I put a vang (?preventer?)about 3/4 of the way back towards the outhaul and did okay, but when the next watch took over, after a few hard gybes the boom bent in a most unappealing fashion. Learned my lesson from now Ill attach it back by the outhaul on loose footed boats.

[Moonchaser2304]

WOW!! GREAT comments...keep them coming!

So, I'm hearing:
============
-Go ahead and go loose-footed
-Get my sail recut to remove the bolt rope and shelf
-Install a car for the clew (actually I already have one)

** I LIKE the point about being able to loosen the outhaul a LOT going downwind to make it more like a genoa on a pole...actually I am embarassed to admit that I NEVER reset my outhaul, but if I loose foot the main there will be much more reason (read benefit) in using the outhaul more in sail trim because it will move so much more easily and the main will reshape itself accordingly.

** Yes, I do have both adjustable lazy jacks and topping lift so boom boom is not a concern

** As far as the "mess" a loose footed main would be when dousing it, also not a concern because the reason I want to loose foot the main is so I can design, and have built, a "leave-on-boom" sail cover, that will need to use the boom slot, combining ideas from 3 or 4 different brands and home-built ideas...that will be a separate post, though..

Thanks for the comments!!

More ideas?!?

[delmarrey]

Originally Posted by FrankZ

Is this because of the loose foot or the new sail. My boat sailed much better when I got a new loose footed sail as well.. though new was probably more of it than loose footed.

I do believe it is the new design/shape. This new one has 4 full battens attached to the mast track cars and has a bit more sail area. Even when I get a little puff I can feel the boat excellerate more then it use to. New well designed sails do make a difference!

Originally Posted by Moonchaser2304

-Install a car for the clew (actually I already have one)

Mine is an external track 6' long w/a bearing-ed car that will take side loads and still move. An in track like what, I believe, you have will jam up with a heavy side load.

................._/)

[Moonchaser2304]

Ah, thanks Delmarrey, I see your point about the side load on a slot-based slide..hmm..maybe that's where I have to stop as far as new toys...and adjust it with no wind load...for now at least