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Designing a sail

mixmkr

Well-Known Member
1st off...buying a $125 sail from Intensity is basically.about the cost of sail cloth even with my Sailrite wholesale prices...and they are pretty much the cheapest anywhere.
But...2 goals...fun and "maybe" point higher. I don't care about class legal.

The idea is a larger but potentially almost flat sail...so I don't screw up the draft of the sail. I presume this might work. I'd sacrifice speed for pointing higher too.
Thoughts? Flat so I can point higher, but less power ( less drag too? ) I'm guessing as well.

Also...using 1.5 oz ripstop nylon vs 4 oz Dacron....which would be about 30% cheaper in cost
Thoughts? (Will stay out of 25kt plus winds!)
 

beldar boathead

Well-Known Member
I’m no expert, but while a flat sail sounds good in theory, I’m not sure it’s going to help with pointing. You need lift from the centerboard to make forward progress and sail on the wind (ie point.). A flat sail won’t generate much power, so not so much lift off the centerboard. I suspect the racing sail is designed to go fast and point high.

I have no idea about using ripstop sail material. Obviously it’s not viewed as the right material for the job, but maybe that is just due to lack of longevity. Maybe someone else will know.
 

mixmkr

Well-Known Member
I tend to think a basically flat made sail, will still have a curve in it when it gets 15kts of wind in it...simulating a draft, so to speak. IDK....thats why Im tossing this out for thoughts.
I do quite a lot of sewing...but its marine canvas stuff like biminis and sail covers. Only repaired sails, put in view windows etc. No sails ftom scratch.
My main gripe about Sunfishes are the lousy pointing. Many of my launch areas are at the back end of coves with the wind shooting straight down the length. Tacking back upwind is like just going perpendicular, back and forth gaining no ground. While on this tacking subject, usually shooting down the shoreline gives me more of a wind angle. Any rate..the launch site is usually chosen due to wind direction. If a flatter sail allowed 5 degrees of higher pointing... i might make it home for supper and before dark!
 

Ticktack

Member
I tend to think a basically flat made sail, will still have a curve in it when it gets 15kts of wind in it...simulating a draft, so to speak. IDK....thats why Im tossing this out for thoughts.
I do quite a lot of sewing...but its marine canvas stuff like biminis and sail covers. Only repaired sails, put in view windows etc. No sails ftom scratch.
My main gripe about Sunfishes are the lousy pointing. Many of my launch areas are at the back end of coves with the wind shooting straight down the length. Tacking back upwind is like just going perpendicular, back and forth gaining no ground. While on this tacking subject, usually shooting down the shoreline gives me more of a wind angle. Any rate..the launch site is usually chosen due to wind direction. If a flatter sail allowed 5 degrees of higher pointing... i might make it home for supper and before dark!
I agree with Beldar, I think it would be pretty hard to improve on a sail shape that has been proving itself for quite a long time. It’s really all about getting the best VMG to the weather mark ( in your case, home)!
 

mixmkr

Well-Known Member
I can agree with not really being able to improve (easily)the already proven sail. However sail shape in most boats is totally adjustable thru outhauls, cunninghams, halyard tension...and stuff like backstay adjusters to flatten or increase the draft. Therefore a sail most likely will be in a middle ground, to allow for the widest range of desired adjustments....in MOST cases.
That noted, Im not looking to improve the current sail overall...just to more permanently make it so it points higher....usually achieved with tighter luff, less draft ..on cruising/racing boats at least. I would figure the Sunfish would react to the same type of adjustments in a similar fashion.
And....im not nearly concerned with power or speed...JUST pointing higher.
Kinda in the same vein as a storm jib . ....smallish and flat...just looking to keep sajl trim balance, center if effort, and speed is totally not high on the list.
 

mixmkr

Well-Known Member
I have a very nice 69 in dry condition. I have the new rudder setup but a wooden blade. I did buy a fiberglass daggerboard (and still have the largest wooden one too). I did add/extend 12" to a wooden daggerboard; but didnt realize any noticeable difference ...but it was a hassle to pull up when beaching not to mention dealing with the boom, most of all.
There's a thread about that...probably a couple years back. Maybe ill see if i can find the link, if you have an interest in seeing pics and construction progress.
Yeah...the new glass board was noticeably better.
 

beldar boathead

Well-Known Member
I have a very nice 69 in dry condition. I have the new rudder setup but a wooden blade. I did buy a fiberglass daggerboard (and still have the largest wooden one too). I did add/extend 12" to a wooden daggerboard; but didnt realize any noticeable difference ...but it was a hassle to pull up when beaching not to mention dealing with the boom, most of all.
There's a thread about that...probably a couple years back. Maybe ill see if i can find the link, if you have an interest in seeing pics and construction progress.
Yeah...the new glass board was noticeably better.
I remember that super-long board. I’m glad you have a modern board.

I think you should experiment with sails, but expecting 5 degrees of higher pointing is very optimistic.
 

mixmkr

Well-Known Member
I have an old sail that ill never use as jt has some staining. Maybe easiest would be to rip out the seams and flatten out the sail. Take it out and see what happens. That would be basically free and just my time.
 

signal charlie

Well-Known Member
Staff member
Skipper says try it and see. She also thinks The Geezer Rig would help. If you had an adjustable gooseneck you could take a minute once you got out and readjust the halyard and gooseneck to The Deck Sweep Rig.

If you don't have it already I'd order some 1/4 inch double backed adhesive seam tape from Sailrite, to help hold the panel seams when sewing them back together. A small zigzag down each side of the seam is recommended 1/8" from the edge. Or 3 rows of straight stitching. V69 UV resistant polyester thread with the proper size needle, 18 or 20 works for us. You'll also need Dacron seam tape for the outer perimeter of the sail, it gets folded in half. 3 inch seam tape (1 1/2 when folded) is overkill, I'm sure Sailrite has something smaller, maybe 2 inch? Rub the fold of the tape down with a seam rubber before sewing, sew on one side, then the other. You may or may not want double backed adhesive sail tape to keep the bias cut edge seam in place.

As for the history of Sunfish sail shape, they used to be pretty flat, and with lighter material in the 60s. So it depends on how old and how flat the sail you are going to recut is. It is fun to look at the broadseaming of the sail panels (curves along the panel seams) and get an idea of where the sailmaker put the different areas of draft once you disassemble the sail. This 67 sf lug sail had quite a bit of broadseaming to develop leech and foot hollows.


Sail draft.jpeg

This draft promotes power over pointing I suppose, for an 8 foot Nutshell Pram.

SailriteKitExtPScropweb-1200x1009.jpeg

You could also contact Jeff, the sail designer at Sailrite, and see what suggestions he may have. jeff@sailrite.com
 

mixmkr

Well-Known Member
I do have an adjustable gooseneck. Im not following how a geezer rig would help pointing....or even the deck sweeper??

I do a lot of sail repair...just not new from scratch....and get lots of stuff from Sailrite with my wholesale acct. Their prices are best for Sunbrella and Tenara thread over any of my other wholsalers
 

Ticktack

Member
I do have an adjustable gooseneck. Im not following how a geezer rig would help pointing....or even the deck sweeper??

I do a lot of sail repair...just not new from scratch....and get lots of stuff from Sailrite with my wholesale acct. Their prices are best for Sunbrella and Tenara thread over any of my other wholsalers
I think Skipper might be referring to the
 

Ticktack

Member
I think Skipper might be referring to the “end plate effect “ that might make the sail more efficient when lowered to the deck sweeping position. I feel like you are destined to building the sail that you envision, if you don’t, you’ll never know!
I’m not a sailmaker so please correct me but I think sails are usually designed with the depth of draft & placement as a percentage aft from the luff to be powerful & efficient in lighter air. As wind builds, the controls you mention are used to flatten & depower to keep the helm balanced & keep the boat on its feet. you mention making a flat sail that will acquire shape as the wind builds, my concern is, will the shape really be where you want it or to far aft which would flatten entry with a hooked leach. I also believe nylon stretches more than Dacron therefor will not hold a designed shape as well.
just my 2 cents!
Tom
 

beldar boathead

Well-Known Member
Here is another way to think about this. A sunfish with a racing board and racing sail will easily beat a Sunfish with a racing board and flatter recreational sail to the windward mark. So your flatter sail may point higher, but you are unlikely to get to a point to weather faster than a boat with a racing sail. That said your experiment should be fun and you will learn something f.
 

mixmkr

Well-Known Member
Thx for all the helpful comments. I havent really sailed a lot this year...so I will have use prior year experiences to make a comparison....whuch may complicate evaluations!
I just remember being late for supper on occasions!
 

shorefun

Well-Known Member
I fun race a recreational sail in our club. The racing sails always move ahead of me, they always seem to be a just a bit better on the upwind.

Of course, that could be I am just not very good at sailing. I can see the racing sails go deeper and dont head up so hard compared how much I fight in a stiffer wind. So all the above makes sense.
 

sawyerspadre

Got kids, need Sunfish.
Interesting thread. Is the a correlation between the sailors who buy the racing sail and the white daggerboard and also happen to be better sailors, and being able to sail upwind faster? Hmmm. Tiller time might outweigh time on the sewing machine!
 

L&VW

Well-Known Member
Thoughts? Flat so I can point higher, but less power ( less drag too? ) I'm guessing as well.

Also...using 1.5 oz ripstop nylon vs 4 oz Dacron....which would be about 30% cheaper in cost
Thoughts? (Will stay out of 25kt plus winds!)
Snark sailors have good luck with Tyvek™.
:)
 

mixmkr

Well-Known Member
Tiller time might outweigh time on the sewing machine!
At the top of the thread, all I was desiring was pointing as high as possible...and to further clarify...even if I have drag my cooler on a windward side. Compared to a conventional cabin, cruising or displacement hull race boat, the Sunfish isnt even in the same league for pointing...which for me makes a difference with no motor and sailing upwind to get home. Plus if the goof-nuts at Farrar Sails didnt muck around, they would have never come up with high aspect, flat top experimental sails. Im no Dennis Connor, but sailing since a kid and own a marine repair business. I just enjoy "busmans holidays" ;-)
 

L&VW

Well-Known Member
I'm no Dennis Connor, but sailing since a kid and own a marine repair business. I just enjoy "busmans holidays" ;-)
I rent-out a cottage for two weeks every summer to a plumber. He "optimizes" the cottage's plumbing, advises on changes, what is state-permitted, or adds necessary devices.

(Ralph Kramden would vacation by Greyhound).
 

Ticktack

Member
I can agree with not really being able to improve (easily)the already proven sail. However sail shape in most boats is totally adjustable thru outhauls, cunninghams, halyard tension...and stuff like backstay adjusters to flatten or increase the draft. Therefore a sail most likely will be in a middle ground, to allow for the widest range of desired adjustments....in MOST cases.
That noted, Im not looking to improve the current sail overall...just to more permanently make it so it points higher....usually achieved with tighter luff, less draft ..on cruising/racing boats at least. I would figure the Sunfish would react to the same type of adjustments in a similar fashion.
And....im not nearly concerned with power or speed...JUST pointing higher.
Kinda in the same vein as a storm jib . ....smallish and flat...just looking to keep sajl trim balance, center if effort, and speed is totally not high on the list.
Ok, I’m sold on the fact that you want to point higher. The problem I keep envisioning with a flat sail is that while it “looks like” you are pointing higher, the side slippage from a small foil with not enough boat boat speed will be detrimental to your windward progress (VMG).
A Sunfish is very dependent on good boat speed to go upwind; sacrificing boat speed for the illusion of pointing higher with a flat sail will not get you upwind as fast.
again, just my2 cents.
 

Dennis Connor

New Member
Im no Dennis Connor, but sailing since a kid and own a marine repair business. I just enjoy "busmans holidays" ;-)
Well, I am Dennis Connor, and I do enjoy busman’s holidays - all I do is sail, sail, sail.

I read your idea. We tried an idea like that on Stars and Stripes one time. While the boat pointed higher, the flatter (not flat) sail kept stalling and losing lift. So we went back to our more standard sail design.
 

mixmkr

Well-Known Member
How about a flatter but 50% larger sail to make up for lost power...(and a daggerboard with embedded lead).
I have an old one design 16 footer (Stinger..looks like a mini Tarten Ten) that has an unweighted swing centerboard...i believe more for slippage and lift. ..but has lead in the lower half...I suspect more to keep the board down, than for any practical ballast.

Sorry..two topics...sail size and weighted blades :)
 
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