Light wind sailboats

Some details that probably got lost in the pages of this thread: The amas are about an inch higher each now than pictured, and I have a newer big jib on the boat at present, with a homemade furler. I will probably need to to some major remodeling to the cross-bars(2x4 lumber) to get the amas much higher. Are you guys saying a non-battened nylon bermuda would pull better than a cut-short H16 sail? I'm building on a severe budget, so I won't be buying custom sails for it. I would be modifying the rig to fit production second-hand sails first. The tyvek sails cost me $15 a piece. No doubt the nice sails are worth it, but it isn't high enough of a priority on this boat, and I may be replacing/changing parts out on it anyways.

Here is a photo from this spring with the original rig as pictured earlier:




Here is the big jib, which is flat-cut, but draws very nicely and pulls the boat along quite well.

 

A quick wipe with an acetone soaked rag will remove the printing from those Tyvek sails.

 

Good to know PAR, I'll try that.

 

Mono hull for light winds

A classic light wind monohull is the Thames A Rater. Google images for that term will provide numerous images.

http://www.yachtsandyachting.com/news/147807/Thames-vintage-dinghy-regatta

it has been claimed as the first class on which the trapeze was demonstrated.

 

that is a very interesting adaptation of skin-on-frame construction. I have been thinking of making something similar to try out skin-on-frame in trimaran type configuration. Very nicely done.

It is easy to raise your amas with a straight beam, just put blocks under the beam where it passes over the gunwales. It will space up the beams and raise the amas, ideally you want the windward ama just above the water so it does not come in contact with the surface chop in your normal sailing conditions.

Your sail definitively needs some work: the efficiency of a sail I have found is as much the planform shape, as the camber, that gives good sail performance. I have gone much faster than boats with much larger sails using a home made fully battened elliptical shaped sail. If you use full battens to allow a much fuller roach, so the top half of the sail is more elliptical shaped, and make it as high aspect ratio as practical (taller mast), you will notice much better low wind power. definitely go with a loose foot sail, I like to bring the clue of the sail down to deck level, and have the lower edge angle up towards the end of the boom. this reduces the vortex loss on the lower edge. A loose footed sail allows you to get better camber on a flat cut field as well (and it is easier to make!). also, consider putting a slight taper in your battens (thinner part forward) so you get more curvature toward the front of the sail than at the back edge.

I also often use Tyvek to experiment with, duck tape costs less than the Tyvek tape, and you can get it in colors or white. It sticks on the Tyvek just as well to make a permanent bond, unlike a lot of other tapes. You an also get two sided duck tape to make lap seams if you want.

I tried the acetone wipe per PAR's suggestion, and it does kind of dissolve the lettering, but it does not really remove them, they just bleed and smear around on the surface. Now I just use cheap laytex paint on it after I am done, it makes for a smoother finish and completely covers the printing. You can go with any color, bright sails are always fun, I go to the back of most custom paint stores and ask if they have any mismixed paints they want to get rid of. The EPA treats paint as toxic waste (even the non-toxic latex), so usually they give it away for free, or for $1 a gallon or something similar. I always find bright yellow, purple, bright red, etc. (someone liked the color chip but when they put the first coat on their house realize it is way too bright for a house, so they bring it back to the paint store).

I always think it is a good idea to paint home made boats bright colors, it looks more fun on the water, makes great pictures. And it is easier to locate the wreckage if they have to send out search parties when you do not come back ;-)

 

Not to mention that the lettering is of no concern.

 

yes, that is true.

but I hate giving away free advertizing when I am out sailing. besides, it is kind of embarrassing when I am out sailing in a boat I built with $50 of salvaged wood and parts, and everone else is out in the high priced dingys, sailboards and yachts. Painting the sail bright yellow, with a bright red hull, means I am also not advertising that I am sailing a boat with cheap construction grade house wrap sails.

let them never know it does not take a lot of money to have a fun fast little tri you can build yourself in a weekend.

 

Yeah the acetone wipe requires a lot of acetone and constantly clean rags. I usually soak the area then make one swipe with a clean rag, flip it, then another wipe. It'll take a few tries, to remove it. A little toluene added (to the acetone) will slow the flash off rate and leave the "tones" on the surface longer. I too have a pet peeve about free advertisements, especially when out sailing. Petros, the special "sticks to plastic" paints, like Krylon's "Fusion" work really well at sticking to Tyvek. I know a few PuddleDucker's that have American and Australian flags painted on their sails, some the whole surface, with good peel strength and minimum weight.

Good to see yet another helpful, productive post from your Jammer. This must bring your total up to 3 or 4 by now . . .

 

I would definitely start with the cut down Hobie sail. It's hard to improve on a professional job, as PAR said. I've used a cut down Laser sail on a windsurfer, worked great. Full length battens can improve a sail, if done well.

 

I'm not trying to be negative, but as a Laser sailor and windsurfer it's hard to see how a cut-down Laser sail would work too well on a windsurfer. Gust response is far more important on a board and the minimal roach and tight leach of a Laser sail is problematic when it comes to that.

 

You're right, but still better than me trying to make a sail! It's only around 4 sq m, and I've taught myself how to windsurf using it (only been out about 5 times). I've used it in 15 or 20 knots (and overtook real Lasers). The rest of the rig is bamboo, and the whole lot is super light weight. Would not scale up well though!

http://www.tdem.co.nz/bamboo-windsurfing-rig

 

True, Well, It did take me a whole winter to make the thing, so it wasn't that fast.

 

build ten or twenty more, you will get the time down...I lost track after 25...

 

That's a great page and a great project - well done!