That's weird somebody posted almost the exact question about a week ago.

How do you mean the battens don't fit the mast????
The battens have to go to the luff sleeve otherwise they might as well not be there! You don't cut battens down and expect the sail to work the way it's meant to.
Is it a cammed sail? if so cams meant for a rdm won't fit an sdm, in which case the easiest way out is to change cams.
Do you mean the battens are sticking out in front of the mast and the sail doesn't rotate?
If so you probably haven't got enough downhaul/outhaul, or the base of the mast is too stiff.
Does the mast have the recommended stiffness and bend curve?

the only severne 5.7 sail i found using a quick search was the 2006 S-1
which seems to be a "maneuver oriented wave sail"
http://2006.severnesails.com/products/sails.asp
and specifies on the above page RDM ONLY
and that is WHY your battens "don't fit"
the sail and battens are made for a Severne Redline 400 cm RDM mast
would i cut the battens NON
do you have the $$$ for a mast - non - AND donut care about the sail - ONLY then cut the battens !!!

Ah subsonic you've hit the nail on the head. The battens have to apply tension to the sail by being tight at each end of the pockets.
If you shorten the battens then you also have to shorten the pockets, so the sail stays tensioned.
There used to be, many years ago, what was known as "soft" sails, these had a few battens around the boom area, that didn't go all the way to the luff.
This allowed a full sail that still rotated easily.
But you can't just stitch the batten pockets up, there needs to be enough reinforcing in there to hold the tension on the battens.
If you've nothing to loose may be worth a try, but remember I'm not actually advising it, think I'd rather get the correct mast.

I would encourage you not to. You will then have a sail that won't work on any mast.

I would say if you're trying to rig it on an old one piece mast, that'll be you're problem right there....

I know it's probably not what you want to hear but I'd probably lash out and invest in a newer 400 2 piece mast (constant curve if you're running severne sails). it'll open up the possibility of being able to use a lot of other sails as well.

I'm guessing you'll struggle to find sails that will fit your one piece mast these days...

mort69 said..

the existing battons just push hard against the side of the mast ,I dout they will even pop.,

this says you don't have enough downhaul. maybe you need to get someone with current gear to show you just how much downhaul is enough.

years ago I went for a sail with Andrew of KA sails, after rigging my sail with what I thought was heaps of downhaul, I asked him "was that enough downhaul". He replied " before you can say you have enough downhaul. First you have to have SOME downhaul."

DON"Tmess with the sail. Get a decent mast.

Couldn't even get them out so left it,looking for a skinny mast hope it has more room to fit around the battons.