just a quick question, would a second hand main from a new merlin be suitable for my 1980 winderbox merlin? theres a nice set on ebay that im interested in.  Many thanks

Depends on the measurements between the black bands - try to get a sail to fit those as it makes the boat go so much better.

Isn't it more complex than that Pat? If you have / do not have a spinny chute the jib tack is approx 7ins different.thus the jib / main overlap or lack of it is quite different and quite important. I rather think that you can't put modern cut sails on an old boat because of the jib tack position !

It depends on the sails !! a six month old set yes a 10 year old set no !!

Lots of people do use new style sails on old boats for want of anything else and go very well. A totally orinally rigged boat will not respond well to this, but modified to inboard sheeting and with some prebend and rig tension in the mast and it will go much better than a suit of 1970s Banks that have been used most weekends.

If you can neither afford or justify brand new sails you could do a lot worse.

What you'll have to watch with the winderbox is that the hull can stand the extra rig tension. It is almost a high tank boat, but does the foredeck come back to the shroud points? If so then with a kingpost or wire strop from the top of the deck to the mast foot you should be ok.

The foredeck does come back to the shroud points, it then returns to the mast with a curve. Will try, theres a set on ebay at the moment and the cut is the same as shown on my certificate of measurements.

The issue is whther there is "boat" between the mast and the shrouds rather than fresh air. if you have a triangulated foredeck you shpuld be ok.

Hi Chris, i have fresh air in between the triangle back to the mast, like where the kite would come through on he really old merlins, thanks for info.

We had a modern main originally which was cut shorter and wider than our measurements and loose footed on our Proctor D section mast. We didn't do very well with it. 
Changing to an old 1970's taller, thinner fixed foot sail was a vast improvement despite the well used-ness! Then we got a decent set to the right measurements and have been going much better ever since.

Ben, I have been watching these sails out of interest and they have gone well. If you miss them I have a set in the garage which I was planning to put on e-bay soon. I don't have the spinny but they are same as those P&B and about the same age. I also have some Batt sails that I will be selling too. E-mail me if you are interested and dont' get the ones on e-bay.