Oversizing sails? Problems?

[OhBrian]

Hello,

I am building a smaller sailboat and already own a high-quality mainsail that is approximately 25% larger that the size recommended by the plans. I would love to save the money of buying a new, high-quality replacement. If I am careful to not overpower the larger sail, would I still expect other performance or safety issues?

Thanks for your comments.

[Giulietta]

Technically yes. Problem

Even if you are carefull in not overpowering, (which I assume you refer to sheeting in), it's still 25% above what the boat was designed, and for that matter, the mast and the keel.

There is a fine balance here...

In light conditions a larger main will give better speed, but with an increase in wind velocity, lift is exponential, so the boat will heel more, and at lower wind speeds, causing possible capsize.

Do you have a keel with weight?

[blt2ski]

The other issue I found out with an 8' pram I built as a teen, and used an over sized main, is in my case, the Center of Effort was farther back, and caused too much weather helm IIRC, and made it hard to control in some wind conditions. Granted I was dealing with a cat rig, but it can cause some other issues.

marty

[AllThumbs]

Can you reef the sail you have? If it is heavilly reefable I might give it a go (not that I know the answer to your question, but I am the experimenting type). Another option is to have the sail you have recut.

Eric

[chucklesR]

If you are building the boat in theory you should be intimate with the boats characteristics.
The short answer is no, the longer answer is no, of course not. Unless a boat is purposely under rigged by her designer because of her intended use or use area increasing the rig without changing the design to handle it doesn't work.

[US27inKS]

Why not go see a sailmaker and have the oversize sail recut to the proper size?