BYYB Forums

Hi Guys.  I am going to make my own Genoa for my 6m Jarcat.  I want it to be furling and reefing so was thinking of making it flat.  It's quite large on this boat with the mast set a ways back to keep the cabin clear of the mast.  My primary question is what will be the loss of power ratio approximately by going flat?  I am only cruising, never racing, and if it isn't too great then I would be happy for that as it would reef well.  I am only using 4oz dacron so I imagine it will stretch a little any way and create a bit of draft plus the the natural bend of the forestay will create some draft.  I have ordered the 'Sail Makers Apprentice' and another book on sail making principles.  I really want to learn to make my own sail as that's how I roll so any advice would be greatly appreciated (other then "hire a sail maker").  I built my own boat, now I want to make my own sails.Cheers and Thanks in advanceAndrew Stokes

As an experiment I just made up a lapper for my weekender.  I used a medium duty poly tarp which was the cheapest one I could find and a single roll of duct tape.  The tarp is forest green and brown.  Gawdawful looking.  Anyway, it was pretty simple to do and didn't take long at all.  I selected one side of the tarp to act as the luff and zip tied it to the forstay of my boat.  I then stretched it using the regular halyard to check the height that I wanted which was already set by the grommets that were pre-set on the tarp.  I then used one of those snap on plastic attachments as an adjustable clew and flew the tarp as a sail.  I moved the attachment around until I got the sail to fly in the shape that I wanted.  After that it was a simple matter to mark and cut out the sail.  Because it is a temporary experiment, I didn't over build it.  I mainly want to test it for light air sailing.  If it pleases me, I will have a local sailmaker sew a nice one for me.

I haven't tried it yet, but I will report back when I get the time to try it out.

Al

Okay, so I finally got a chance to try out my lapper.  I waited until we had a day that had reasonably light wind and light traffic.  The wind was around 5 to 8 mph with gusts all the way up to 12.  Once I got the lapper to settle down, I got a nice airfoil shape and it was real steady.  I couldn't point any higher, but my speed was quite a bit better.  I also noticed that the whole experience seemed steadier even in the gusts.  Weather helm was not changed.  The amount of helm deflection seemed the same.  The lapper was not as forgiving as the stock jib when it comes to sail set.  I spent a fair amount of time getting the set right after a tack, but that should settle out with time.  Tacking was not affected.  Heaving to was slightly easier.  Ghosting along in wind that I couldn't even feel was a nice surprise. 

All in all it was a positive experience.  I am going to beat this experimental sail up and if it still makes me happy, I will get a local sail maker to sew up a nice one for me.  So if anyone is looking for something new to try, make up a lapper and see if you like it.  I figure I have between $15 and $20 tied up in mine, so nothing to lose.

Al

Just out of curiosity, I measured my lapper against the stock jib.  I found that when I overlaid the stock jib over the lapper that the angle of the clew was a very close match for the angle of the stock jib.  The difference in area was fourteen square feet.  So, total sail area went from 120 sq ft to 134.  I don't know if that is significant, but it did make a noticeable difference in feel. 

Al

On a small lapper, the clew angle will be similar, but as the amount of overlap increases, the angle and the height of the clew must rise, to retain a reasonable sheeting angle.

I've made sails previously and having done so, I now am more then willing to purchase them. You really don't save much if you buy a kit and the hand work is tedious, hard and not worth the effort in my opinion. Making sails from scratch is difficult, without a good understanding of the various things, most sail makers take for granted. Things like; mast bend, luff, foot and roach round, size and placement of reinforcements, battens reef points, panel dimensions to offer the right sail camber for the wind strength desired, etc.

Sail makers earn every penny they charge, as far as I'm concerned. This said, I've made poly tarp sails, to figure stuff out, but once I've got the dimensions, I have a set made professionally. A well built sail will set nice and last a long time. A crappy sail will never pull well and probably will not last long either. I'm just not good enough to make a well setting sail, that can last a long time. I recently made a new rig for a ketch of mine. I poly tarped a jib, genoa, a 120, a main, a mizzen a staysail and a tall boy. The staysail I'll keep as is, because it's a light air sail, made from rip stop and it sets well enough for it's intended use. The mizzen was cut down from an old main, so it works well, but the main, jib, tall boy and genny will be purchased. I have a Flying Scott spinnaker that fits, so I'll just use it. It's interesting to fly 5 sails at once on a 23' boat, but this is a rare thing to occur. In light air, I can hoist a spinnaker, the tall boy inside this set flying, the main, the staysail and the mizzen. A nice sight, but a lot of work, to keep them all drawing. The 4 sails will cost about $1,200 bucks total, but they'll last quite a while and set well. I may ship the tall boy as it a sail that doesn't get used very often.

So, yesterday I went out for a nice relaxing sail on a somewhat larger lake nearby.  Because the wind was between 5 and 15 mph, I set the lapper.  At the end of the trip the wind turned out to be just that.  I sailed off the dock and turned on to a broad reach which happened to be the course I wanted.  I was exploring a new  part of the reservoir that I normally sail on which also made it interesting.  Right away I noticed that I was doing much better speed than I thought I would.  I knew that there was a  bay up ahead of me that I would have to beat into the wind to explore.  When I got to it, I discovered that it was much narrower than I thought it was and dead into the wind.  Duckie did a pretty good job of making headway into the channel, but I figured that It would take up time I needed to explore the rest of the lake.  I may be wrong, but I credit that better windward performance to the lapper. 

I turned tail and ran downwind out of the bay and down the lake.  I was able to sail downwind with the jib pulling along with the main so I made pretty good time.  When I got to  the causeway, I had to turn around and head back to the landing.  I was able to set a course for the landing and hold it the whole way.  It was a fairly close reach but not close hauled.  My speed was unprecedented.  At well below 10 mph wind speed I was roaring up the lake like never before.  The wind continued to  build until there were small white caps and I was able to maintain my course without having to adjust too much.  I was able to sail up to the dock and step out just like I knew what I was doing. YIKES

Maybe its just me, but I think that making that lapper was the best thing I did for the performance of my weekender this year.

Al

A jib with a modest overlap (less then 140%) will always improve a sloop. The old school thought was called the "slot effect" which is actually just bogus nonsense, but it sounds good. In reality what happens is the wind sees a much bigger sail, because the jib overlaps the main. With a 90% or 100% jib, there's enough of a gap between the two sails that the wind sees both. Just like biplanes discovered, one big wing is more efficient than two smaller ones.

On days when there's little wind a really big lapper is handy. You can't carry it up as high into the wind, but it will make the boat go, when the regular working sails don't. Most sloops carry several headsails, just for this reason. On my big sloop, I have 7 headsails. Of course most don't need this many, but if you want to get every ounce of energy out of a boat, you put headsails matched for the wind you're in at the moment. This means a big ass jib in light air, then you progressively change down in sizes as wind strength increases.

Yeah Paul,

That is just what it feels like.  After my last outing I was thinking about how good the new sail was doing, when it occurred to me that I was showing more sail to the wind and just that was giving me the extra oomph that I was feeling.  I do notice though that my highest tell tale is streaming much better with the lapper than the stock sail.  I have noticed that I have a real tough time getting that top one to stream with the stock sail.  I have tried all the combinations of sail set I can think of and have found very little success.  With the lapper I find that the top tell tale streams normally and not streaming is the rare exception.  I also notice that I can see what the lapper is doing better than the stock jib simply because it is bigger.  Maybe because I made it so light, I also notice that it warns me quicker that I need to fall off a little.  That has come in real handy in keeping up my speed and maintaining a course. 

I'm very happy with what I have, but I am thinking about pushing it a little more.  How far do you think I can go before I start to see trouble?

Al

There's no such thing as too much, but the more the overlap, the lower you'll sail into the wind. Going upwind, you need to haul the jib in fairly flat and tight, which a big genny can't do, because of the shrouds and the sheeting angle. When you get too big, it becomes a spinnaker and all you can do is go down wind.

The upper tell will fly (stream), if you get the sheet lead correct, no matter what kind of sail it is. With the sheet lead too far aft, the upper windward and usually the lower leeward tell will flutter. If the lead is too far forward the opposite will happen. When you're "in the groove" all will "stream" aft. Leach tension plays a role here too. This is why modern sloops have a jib lead track on the side decks, so the fairlead block can be moved back and forth to find the sweet spot.

Breathing life back into the dead,

This spring I bought a compact 16 to help further my education into all things sailing.  I  bought the latest model, the 16/3,  which has more  head sail than the earlier models.  While fooling around cleaning up and cataloguing the pile of stuff that came with the boat I noticed that the stock lapper for the compact was a pretty close match to the lapper I made for my weekender.  Long story short, yesterday I tried out this new to me sail on Duckie and after some more fooling around, I got it to work pretty well.

I went to the landing that I usually use for my experimental sails when the rain finally let up for a couple minutes and the wind was below 10 mph and not a lot of traffic.  It took me longer to set up because I had to get the new sail to set right and fit with my regular sheets.  In the end I rigged it up so that the foot of the sail was about a foot above the forestay clip.  This put the head of the sail almost to the block at the top of the forestay.  With the sail attached this way I got a pretty good shape when I stretched everything out. 

The wind was pretty light and shifty at first, but once I got out into the lake is steadied out to a perfect breeze for testing a new sail.  As with the lapper that I made it took some doing to get it to quiet down and pull steady.  Once I got it pulling though I noticed that I was moving along at a pretty good clip for such light wind.  I was able to point as well or maybe  better than with my homemade lapper.  Controlling it was about equal to any head sail that I have tried with response to gusts maybe better than the homemade.  I was unable to heave to for some reason that I will have to figure out, but other than that it was a very successful sailing day. 

I  bring this up for those who might like to messabout with a larger head sail on their weekenders and don't want to make their own.  If you know someone with cp 16 who would let you borrow a lapper for a test sail or if you can find a used one somewhere, it might be worth while to take a test sail.  I think now that a larger head sail is a positive thing on a weekender.  I know that this old sail has found a new home and job on my weekender.

Al