maandag 27 juli 2009

test-sail-week

Just back from my first week sail with my brother. We had not so good weather, still a good time, but also some problems. I started to learn about what works and what doesn't on the boat, hopefully other builders will benefit. Didn't take as much pictures as I should have, sorry. Again a lot of text.

Starting with something not working yet: the supports under the wingnet-support. First day one broke in the middle. I took a picture at the end of the week and now I see the other one also broke. It's not a very big deal: the supports work without the two studs underneath (especially if you make sure you lace the most outer eyes on the trampoline tight so the trampoline can't sag too much at the outer end). I will mail Ian about this, maybe he'll have to look at this part of the design. For the time being I will leave it as it is.
The wignet-support itself is in my opinion a really nice idea: it's looking great and it's nice to have the trampoline more or less level and above the float decks.

Below is a picture with the mainsail up. Upper batten is not in the sail on this photo, that's why the top is sagging. My mainsail has cars on every battens, this works ok. I made the mast a tiny bit longer than the plans specify, but maybe should have made it even longer. The mainsail only just fits, I had to fix the lower corner of the luff to the mastfoot with a shackle to get it low enough. No space to fix a tackle to tension the luff, as I planned (will have to put a cunningham in the sail).
I first wanted to keep the rig simple with no winch and no lines to the cockpit, but the week sailing taught me this doesn't work. I will put a winch at the cockpit + stoppers, and lead the halyards to the cockpit.
Looking at the picture above (third day of our sail) it's hard to imagine the day before Hans and I had rough weather and damage to the boat.
We planned to go sailing on saturday, but there was too much wind for a first sail (beaufort 7 = appr. 30 knots) and we stayed at the marina working on some details. Next day the forecast was better. We started on sunday morning with a nice sail with light to moderate wind, but weather changed very quickly in the afternoon with spells with winds up to 7 - 8 beaufort (or so I was told).
We managed to sail to the wind to the lock near our destination, got the sails down and motored to the lock. Near the lock I released the throttle of the outboard to have a good look at the situation, and the motor died. We couldn't get it going again and before we knew were blown downwind on a coast with a dam(n!) made of piled rocks. We had to be pulled off by another boat, and had considerable damage around the keel of the right float. Amazingly only a lot of deep scratches and dents, but no visible big cracks in the laminate. The sandwich panels proved to be really strong (apart from being prone to denting, that is): when we were banging on the rocks I was sure the whole float would be crushed.
I didn't want to sail again with an outboard I couldn't trust, and on monday I was lucky to be able to buy a quite new one and get on with the sailing-vacation.

And now for something completely different: tip for other builders. Put a rubber ring between the bearing pad and the studs for the hatch. This way it's easier to firmly fix the studs in a certain angle.
Another thing to bear in mind: the eye for the raising wires of the mast is too high for a small person to reach. On the picture below I'm stretching as high as I can. I'm 1,68 meter tall. I'm going to lower the eye 25 cm or so. When you use the raising bars at the side of the cabin, as per plan, it's probably not possible to put the eye lower because the bars won't be at the right angle anymore but I don't use the bars. Below a detail of the clearance of the lashing at the wingnet support. As you can see it's possible to cut the support away to - say - 4 cm to the corner of the support and still have plenty of clearance. Folded the lashings rub against the support, but I guess this is unavoidable. The jib has given us a lot of trouble. In the picture below we had it on it's furler, but that only worked in easy conditions. In trying conditions, with gusting wind and in need to quickly get some sail away, it didn't work. At all. The low part of the jib would roll and the upper part wouldn't - leaving a big pile of unrolled jib banging wildly at the top of the mast. We removed the roller, made some hanks on the luff of the jib with pieces of 4 mm dyneema, and hoisted it the normal way. Some of my ideas after this week sail:
  • Don't hoist the furling jib with a small line from the top of the jib through the (fixed) swiffel to the furling drum. It's a nice and clean system when it works, but a pain when it doesn't. On our first eventful sail on sunday we had to get the jib down in big winds and it wouldn't furl. Hans had to crawl to the furling drum to loosen the hoisting line. No fun at all - luckily at that time we were in open water with plenty of clearance to mess around with the jib. From now on I'll only hoist the jib with a normal halyard which can be loosened from the cockpit.
  • It's difficult to hoist and lower the jib (and tie it down on deck) in stronger winds and waves when the jib is not on a furler but just hanked to the forestay. The foredeck area is small to work on, especially because it's sloping down and it's got the jib in the way. We opened the front hatch to have a sort of secure position to work on the jib, but that is not ideal. I will for certain install front nets on the boat: it will help a lot to be able to safely work on things on the foredeck.
  • The problems with furling may be partially due to the low forestay/luff tension. I'm going to try if it's possible to put an anti-torsion cable into the luff of my jib (like the ones made by facnor) and see if that helps. If it doesn't I might switch to a full blown reefing furler with an aluminium luff profile, but I hope this won't be necessary.
  • With the jib low on the deck sailing to the wind it's hard to get a good view of the boats downwind. I may put a window in the jib.
  • Put the camcleats of the jib on blocks (1 cm or so) else you will have trouble to get the sheet in the cleats in stronger winds.
  • (Should have know this....) Put a piece of strong plastic on the corner of the cabin where the jib-sheet runs to the cleat, else the sheet will grind through the paint and fairing in no time.

I worked out the tiller and believe it's fine now. I started with a long tiller with a short joystick (as can be seen last two pictures on this entry) but that didn't work because the sheet + traveler line were tangled in the tiller + joystick every time you tacked.
Now I've shortened the tiller to be just long enough to stay in front of the traveler, and made a two-sided joystick. Both sides are 2,5 meter long. They are fixed to the front of the tiller, and the mainsheet hangs in front of the tiller and the joysticks, and doesn't get tangled anymore. The joysticks are made of two pieces of 3/4" pvc electricity pipe, a piece of reinforced pvc tube from a kite shop as the pivot and three bolts. It cost me about 6 dollar alltogether and it works fine.
On tuesday and wednesday Luis Matos from Portugal (wearing the hat on the picture below) paid a visit to check out the boat for real and to get some ideas for his own build. He's an experienced sailor and could give me some good advice. Luckily those two days were good sailing days, and we had some really nice trips and time to get to know the boat in normal conditions. Time to sum up some of the impressions about sailing and motoring the boat:

  • The folding is just amazing and works really well effortlessly.
  • The boat sails really well, also in choppy (but not too high) waves. It is VERY dry compared to the monohulls I've sailed in similar conditions.
  • To the wind we were at least as fast as much bigger monohulls, downwind the same thing when there is not too much wind. With more wind the boat picks up speed and leaves the monohulls behind fast.
  • The boat will pick up speed to about 7-8 knots easily, and then seems to stay on that speed until there is enough wind to really push it. Then it will suddenly accelerate fast to above 10 knots. Top speed so far has been about 13.5 knots with jib and single reefed main and for me that was fast enough for this first week. The rig + sails still need a lot of tuning (luff of the mainsail is not tensioned right, for instance) so I guess there is room to improve.
  • When the boat goes over 10 knots, it lifts up the bow of the main hull a bit like a powerboat on speed. I was a bit surprised, because I thought the bow would be pressed down a lot when powering.
  • Although the jib tracks are short, they are long enough to trim the jib if you also have a plate at the back of the jib to change the sheeting angle.
  • With the boomless main you need the 6:1 + 4:1 = 24:1 sheet system, else you won't be able to sheet in the main far enough to go to the wind.
  • Not sure about the trimming of the mainsail yet. While reaching it has the tendency to twist a lot and hang against the shrouds, even with the traveler all the way out. Going to the wind twist control with the traveler seems ok.
  • Getting alongside the dock under power is difficult because the boat is more or less square. When the bow of the float is nearly at the dockside you usually have to make a sharp turn, but when you do that the boat will more or less pivot around your centerboard and will be in line with the dockside but about 1,5 meter away from it. Hope the drawing below will help to explain.
Maybe taking the centerboard up might help a bit, but then the boat will drift even more. First thing I'm going to try is to put big fenders, or maybe even permanent rubber profiles, on the bow of the floats so I can just 'park' the nose of the boat against the dockside and then push the back to the dockside with the motor.
  • Last thing: camping in the boat is going fine! I thought it would be a bit cramped, but it works out very good. I've got a lot of interior room because of the centerboard, maybe it will be a bit more cramped with the daggerboard case. With the all white basic interior with blue cushions and the pop top raised a bit it's a nice place to stay when it's raining outside.
    Luis took a small tent and put that on the trampoline to sleep. That worked well also.

And finally: this makes it all worthwile for me. Sailing your self-built boat on a sunny day doing 12 knots effortlessly with almost no heel.

1 opmerking:

Andrew zei

Thanks for the insights and large pictures. Enjoyed seeing you and your brother sailing! Looked like a light helm.