One of the reasons I went with the spritsail over the much more practical lug was because I wanted to experiment with a topsail that I’ve seen in pictures of Scandinavian boats. The shad boats of North Carolina also used a topsail, but they had another spar along the foot which seems like too much complication for a 15′ boat.
I’d pretty well figured out how to rig everything from looking at pictures, but WoodenBoat issues #27 and #157 have some good articles by Joel White and William Garden about how they rig a topsail. Basically the sail will be laced to a ~13′ spar which hangs from a peg at the top of my mast. A lashing around the lower end to the mast keeps everything vertical. The sheet will go to a beehole at the end of the sprit and run down to a cleat near the heel.
Since topsails are cut flat, my original plan was to make the biggest triangle I could from three yards of 60″ wide 4oz Dacron which would give me a 22.5 square foot sail. I asked Todd on the Woodenboat forum for his thoughts to make sure I wasn’t completely crazy and he gave me a bunch of great advice. The panels should be mitered to get the cloth running in the most stable direction, the luff has 1″ of round, the foot and leech have 1″ of hollow. Corner patches should be aligned with the base material or split the difference at the miter. Basically he turned what I thought would be an afternoon of work into something a lot more professional.
After some tinkering around I got the seam margins figured out and everything just barely fit on my three yards of cloth.
I attempted to draw the panels with a pen held in my CNC plasma cutter, but an error in zeroing it drew the first two corner patches in the wrong spot. Other than that, it looked like it would have worked really well. I had the cloth taped down with painters tape to a 1/4″ sheet of aluminum.
So I called in a favor to a friend who owns a print shop to print me off some templates which I cut out and traced onto the cloth. Luckily Sailrite sent me an extra 6″ and I was still able to fit everything.
Here are all the panels cut out and it looks like it should work. Not much waste!
Got the top and bottom halves sewn together, now to join them and hem the edges.
My wife helped me guide the cloth through the sewing machine to get the two halves sewn together, the foot and leech hemmed over, and a 3″ wide piece of 5 oz Dacron tape folded in half sewn down the luff. Also the stack of three of corner patches. Every seam was taped down with 3/8″ double sided basting tape which I’ve heard gives the sail a surprising amount of strength.
I had some 5/16″ spur grommets left over from my main sail kit so I evenly spaced them out about every foot down the luff. I was pretty surprised my designed 1″ of hollow and round came out exactly right in the finished product… there was a lot of opportunity for errors to accumulate. I thought about buying green cloth and making the panels alternate white and green to show off the miters, but decided against it. Now I kinda wish I had.
I built a quick and dirty topmast out of a fir 2×4′ ripped down the middle and rounded over. The sprit got another beehole in the tip and another cleat added near the heel. A loop of stiff line on the topmast slips over a peg epoxied to the side of the main mast and a pennant from the clew goes through the beehole in the sprit down to the cleat. It works well enough and I *think* I’ll be able to do it out on the water. There’s a few bugs that still need to be worked out though. The clew’s pennant is not pulling nearly inline with the mitered seam, so I think I need to move the beehole down the sprit a bit.
Well as it turns out… I’m an idiot. The topsail isn’t quite symmetrical along the mitered seam and I had it laced on upside down. I flipped it over and the sheet pulls quite a bit better now. So no need to go drilling more holes in the sprit! I also experimented with hoisting the top mast with a halyard instead of trying to hook it on a peg at the top of the main mast. I think this is the way to go, even though I was trying to avoid more lines to deal with. The binding issue seems to be fixed since it lines up behind the main mast now.
I tried sticking the 15′ topmast under the jib and out over the bow like a bowsprit, but it interferes with how the jib sets. Maybe I can stick it out the back, otherwise I might need to think about making the mast two pieces.
To raise the sail, I first hove to, tied the sheet onto the clew, and unrolled the sail. In the future I’m going to change this to a clip or something so it’s a lot easier.
Next I tied the halyard onto the topmast with a rolling hitch and slid it up between the sail and sprit.
Things were going along way too smoothly so the sheet decided to tie itself in a knot around the end of the sprit as the sail flapped away. I managed to poke the knot off with an oar, but then the mast slipped out and the whole thing turned upside down on the far side of the mainsail. That involved taking everything back down, getting the lines sorted out, and trying again.
But eventually I got it situated. The mast bows quite a bit more than I was expecting and I later lashed the top mast to the main mast in a better way so it didn’t lean back so much. It almost seems like the sail is too big in actual use, but I need to try a stiffer topmast rigged more vertically before cutting the sail down.