Background, I have a free sailboat, on trailer, no mast, no boom/ spar ,sails, a few other key pieces are missing, but can be fabricated. It's a16' scow. Melges M16. It needs to have stays about 3/4 up the mast to the sides and bow. The proper mast exists somewhere, as do all parts, not even questionable to look for them, not worth it.
Question
Use a windsurf sail on a Ws mast, boom yet to determined, Ws boom may work
Since the stay attachments would prevent the sail from installing on the mast , any ideas on how to attach the sail?i think I could install it ok ,then downhaul could be a problem , I think I can dh just from the bottom pully / or grommet , not so much as we do , but enough to be loose yet produce.
sail sail would be 10m , umm maybe down to 7.5, it used a jib of about 3.5m , which would be easy to do.
Could work with just a jib, but would it go anywhere.
Im used to my ideas not working, but sometimes even a blind squirrel finds a acorn.
the centre of effort on a windsurfing sail would possibly be too high and the boom would also be very high.
Best just to get a sail made or buy an old laser sail and re-cut it.
The mast can be set freestanding if there's enough bury at the bottom - maybe about 500mm. Trouble with that is that you cant use the full length for a sail so will have to use a 7.5 on a 490 etc. The other problem is the top of the sail will lay a long way off so sail shape will be compromised. I think you will need to find a mast section somewhere - something secondhand off a 125, or a sabre or even a small beach cat (very small).
Since the boat is free, you would want similarly priced other stuff. Find someone whom is giving away their really old gear .... then cut some the foot off of it.
Your stays dont have to be too tight -> make a double-U-bracket which clamps to the mast.... using said old sail, cut the mast-sleeve at the same spot. Once you thread the sail, clamp it through the hole.
Edit: 
this is the mast mount. The stays must have a serious stabilization of the mast.
Probably a older windsurf sail like really old, not rule out a more modern one, maybe smaller.
Matthew: the u bolt concept , I had not thought of, to install after the sail is rigged in the mast, good one.
appreciate all comments and suggestions, I have found a few sails online , cheap, that could work, ideally find a sailboat mast with boom , then with or separate a sail that fits ,fabricating the bottom fitting .
Said boat, rather unique, has twin rudders, has twin centerboards, very outside.Melges M16, no serial number, prob 1960-70s.
Please note that the picture above from Mathew is not using a windsurfing sail, the clew position is way lower.
Select to expand quoteMadge said..
Please note that the picture above from Mathew is not using a windsurfing sail, the clew position is way lower.
^^ ... it even says that on the sail and the boat.
The point was, you can stay a mast that has a sleeved-sail. And you can use a plain old boom. The pic also shows that the CoE of those sails, is much higher than windsurf sails (which have the CoE at/near the boom).
Given that base... I'd replace it with something with a connector and universal-joint, such as a windsurf baseplate (say Streamlined, Chinook, etc). Then you can use some of your existing windsurf gear (again a no-cost solution).
Select to expand quotemathew said..Madge said..
Please note that the picture above from Mathew is not using a windsurfing sail, the clew position is way lower.
^^ ... it even says that on the sail and the boat.
The point was, you can stay a mast that has a sleeved-sail. And you can use a plain old boom. The pic also shows that the CoE of those sails, is much higher than windsurf sails (which have the CoE at/near the boom).
Given that base... I'd replace it with something with a connector and universal-joint, such as a windsurf baseplate (say Streamlined, Chinook, etc). Then you can use some of your existing windsurf gear (again a no-cost solution).
Never thought of that, a windsurf base . That idea is sweet !
but will 3stays , bow and sides keep the mast up?
Yes, but being short, I don't feel will offer the downward leverage needed.
using a Ws boom , would install easily enough, needing a line boom to mast near bottom, a line from bottom mast to mid boom then straight down to the floor thru pulley to sides to cleat off, one additional line from boom end to rear of the boat , to secure sideways draft/ wind .
I have 2 other sailboats that use a similar rigging method, a third that I sold, similar, I made a jib from a windsurf sail, but so easy on its proper mast .
i see this idea coming together
You just need to hunt around for another dinghy rig and use that. They can be found cheaply here and I feel certain they can in the US too. That way you get all the bits and you can modify to your heart's content and make a boat that sails nicely. Mast, two shrouds and a forestay (you dont need spreaders for a cruising dinghy) a jib and a main and you'll be away. Do it!
The Melges is a heavy boat, whereas windsurfers are light. The high stability of the Melges and its need for high power mean that a dinghy rig will normally work much better than a board rig
Select to expand quoteChris249 said..
The Melges is a heavy boat, whereas windsurfers are light. The high stability of the Melges and its need for high power mean that a dinghy rig will normally work much better than a board rig
The Melges is a popular class that is actively raced, and as such, people will turn over sails fairly regularly. I would contact the class association and see if there is somewhere you can post a wanted ad for a full mast boom and sail, you may be surprised at what people have in their garages that they are willing to part with at little or no cost. Particularly if it gets an old boat back on the water.
I would think as Decrepit asks ,
If u could attach to boom head , it would work best .
Mast flex , sail twist and all that stuff ,
No hope of ever pointing as high .
I thought I was the ants pants , on a RB , with a adjustable RB sail , with an oversized CB ,......
When a dood in a mini bathtub got an extra 15 deg on me .
I was squeezing so tight I almost stopped and my board was farting.
Dont even mention cats 
Select to expand quotedecrepit said..
can you attache the stays to the boom head?
This does have merit, esp an additional head above the boom head for the sail, attach stays to it, removable then.
the need for speed , it's gone , so this is a absolute play thing, rare I even see another sailboat .
i contacted Melges, they weren't what I call helpful , I have since been on several forums looking for parts, it's easy to find a mast and boom, that I can adapt in the correct length, I'm thinking that I should pursue that Avenue .
^^^
That's awesome , use the motor to get on the plane , then flip the motor up and your on your way .
No more bearing downwind losing ground and sail pumping 
How come the boom is laying on the dock?
It looks sweet so long as their is no particular destination.
