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Wommasehn last won the day on November 16 2020

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    Tübingen, Germany
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  1. It's been a long time now.... Of course, the CB is ready, the boat long time in the water and almost everything is ok. But I feel, I should complete my report. I spent a lot of time and epoxy on profiling. Fearing that it won't make a noticable difference, I wanted a reasonably good NACA profile anyway. A template helped a lot. Then, I glassed it over with biaxial and did the rope-trick. To move it, I attached a tackle to the workshops ceiling and a loop through the second sheeve of the fiddle block. I hoisted it for clearence over the workbench and then I could flip it over. Understanable?? Then of course the painting with primer and antifouling. As I wondered whether epoxy primer or underwater primer was better, I used both. Then, I moved on to restore the CB-trunk. Was worried whether the board would still fit in. It turned out that the trunk was wide enough - but not straght. So I tried to sand away the high spots from below. Then again the glassing and painting. I found out, that sanding overhead in a dark and narrow space, lying on the ground - or applying goo and glasscloth overhead in a dark and narrow space, lying on the ground - or painting overhead in a dark and narrow space, lying on the ground is equally enjoyable...... Meanwhile, I reinforced the cabin-side of the trunk since the additional CB-weight must lead to additional loads. I put in bigger and newly taped fillets in some places. Then came the biggest challenge: putting the thing back in. Just about the only task around Muckla which I can't manage single handedly. I asked a friend who (besides a PHD in law) has a cupboard full of trophies for weight lifting. And I fitted a caster-board with long nuts in each corner , reinforced the corners with additional hardwood blocks and drove 16 mm threaded rod through each corner (picture maybe later) . So I can wheel the thing around and lift it up by turning these rods (by hand and by cordless drill). Together we carried the CB from the car to the boat. The stern was lifted upwards . CB was clamped on its castered board (trailing edge upwards) wobbeled in position, then slowly lifted, then I attached uphaul and downhaul, then we shoved the CB forward. Then started a longish process to line up the bushings of the trunk sides and the board itself. Then inserting the pivot bolt with gaskets washers and nut. BTW: for gascets , I found some kind of paste, used by plumbers. You form a bit of it into a saussage which is put as a ring round the bolt. When the bolt is tightened, it is pressed flat and seals up the joint. It stays flexible and watertight. Works great. Everything seemed ready. Well, it was not quite ready: The rope-trick-rope was too thick, I had to plane away a part of it and the whole thing has way too much friction when totally hauled up. When everything else was ready, I towed her to her summertime berth to a small lake named Goldkanal (the gold channel) and launched her. When I have the CB up, it doesnt go down in spite of its increased weight , but I have to heavily pull on the downhaul to get it down properly. So I simply don't pull it totally up. Now there's already a job for the coming winter. The friction of the not-quite-fitting spots will abrade away the paint and show me where to take away more material. I hope, I can do that whithout taking out the whole CB again! But otherwise the thing works very well: i can really feel the increased righting moment. Two weeks ago, there was our annual club race. Fairly strong wind this time. I was glad that I could "hire" someone from "the other boating club" to join me as a crew. Allthough his main job was "living ballast", he too enjoyed the racing. And we even won in our class.
  2. Hi Frank, the CB has been maintained, repaired and altered for a few times. It did'nt spend all those years inside the trunk. , This is me, doing some repair whithout taking it out..... As for leaden wheel weights, they are hereabouts nowadays mostly made of zinc or steel and I found it easyer to ask at the scrap yard then go through all the garages in town. "Muckla" is a "Diabolo", a 20 ft plywood sloop. Back in Jan. 2019, I posted a more detailed portrait of her in this forum incding some pictures. So if anyone wants more information..... Mucklas btw are weird, small beings, some of them resembling various animals, that appear in the childrens books-series "Petterson and Findus"
  3. Meanwhile, I have bedded the outcuts in plaster , cast moulds from them and cast lead into the moulds. Purchasing the lead was a bit funny: I called a scrap yard if they had lead. The guy on the phone said, I might come the next day. I went there and found nobody, no bell to ring, no open door, no office. While I looked around, someone opened a window in the next house and asked, what I wanted. It was the owners daughter who told me to come back later. Later I came back, the window opened again and a voice said that someone would come. Out she came and told me that her father was already gone. She showed me some kind of trash bin with scrap lead and said that I might take what I liked. I asked for a scales but ther were none. "So how can I know what to pay?" - "just take what you want and give 10 Euros for the tip-box". And that I did. I gave her 10,- and took some weights, some pieces of old pipe and some folded sheet-lead until I estimated, I had 10 kgs. I could have taken a lot more, including a crucifixus - but it felt too awkward thinking of melting down Jesus...... Here, is the dry fit of one of my leaden slabs. The casting did'nt go exeptonally well - but sufficient for my needs. As for the reinforcing of the upper part of the CB, I decided to follow my gut feeling and go with the threaded rod. Here it is on one side , already epoxied in.
  4. Mucklas Centerboard pivot - or rather the bushing in the trunks wall - has an issue: it leaked until I fixed it last summer from inside the cabin/the bilge. Since then it seems watertight but I fear, there might still be water ingressing into the plywood from inside the trunk. To take care of that, I had to take out the CB which is a nasty job. Only getting it back in is worse. Now that the board is out anyway, I want to take the opportunity and put a little more lead in it. You might call the thing "swing keel" anyway if you like. It is made of 4 layers of 12 mm plywood , with the lower parts of the two middle layers being replaced by lead-plates. So the ballast is in the lower third/forth and in between two plywood parts (yes, meanwhile I know that solid wood would be stronger but this is how the designer specified it and it has held up for about 25 years now. Can't be totally wrong). A few years ago, I sawed out a chunk in the middle, made a mould from it and cast it in lead. Now, I decided to take out pieces of the outer plywood layers close to the lower end and cast them in lead too to create two more leaden pieces low down. They will weigh something like 4 kgs each. This will give a total of around 65-70 kgs of lead in the CB/swing keel. The hole on the lower side of the picture is the pivot-hole. This is the starboard side with the piece of ply already taken out. Of course, I will glass the whole thing over which should add a good deal of strength -but then again, I am not quite shure if this is enough. The critical region is where the CB exits the CB-trunk. There is the fulcrum which takes the load and there is the transition from the rectangular part inside the trunk to the NACA-profile. The board fits snugly into the trunk so there is hardly any room to make it thicker and hence stronger. Now, finally here's my question: should I rely on the fibreglass for reinforcement (I could take off some of the wood to get in another layer of glass) or should I rather rely on metal ? For the latter, I have an idea: I might router a groove of maybe 20 cm lenghthwise on both sides through this loaded zone around the CB-slot and epoxy in a threaded rod. This might give a lot of additional strengh. What do you think??
  5. In the Main Forum, I posted a thread about Mucklas new rudder and I promised to tell you how and why it became necessary to make a new one. Here's the strory. Every year in the autumn, I get a week off for single handed cruising , normally on Lake Constance. Lake Constance is'nt just the only body of water big enough for cruising in the region where I live, it is also very beautiful with picturesque and neatly kept up towns and villages all around and rolling hills covered in forests, fields and vineyards. To the south-east, there is the majestic backdrop of The Alpes. The lake is 63 km long and 14 km wide; there are ports and marinas aplenty . People of former days liked the region too so everything oozes history - from remains of stone age settlements (and a splendid open air museum of replicas) through findings of the Romans, medeival- als well as baroque castles and churches to more modern developments such as the Zeppelin-Museum and aircraft industry. Lake Constance is an international body of water with parts of the shoreline belonging to Swizzerland, to Austria and to Germany respectively. It is also the souce of drinking water for several millions of people. All this surely makes it understanable that there are strict rules for boating (and everything else) even though not each and every of these make sense to everybody. Last year I had to re-certify Muckla. She was examined, particularly the emergency-equipment and found good. It was a sunny day with a light breeze. After I had got my certificate and sticker, I cast off and headed SE for Wasserburg under a light westerly breeze. Slowly the wind picked up and I enjoyed a quick deep reach. As there were some heavy clouds, I donned my foul weather gear including PFD and sailed on, now and then in full planing mode. Due to that course, it took me some time to realize how strong the wind meanwhile was. After a jibe, a strong gust hit me and made her luff up and heel over a lot. With my dinghy sailer-reflexes, I dumped both sheets and rolled in the jib (well, almost, there remained a small proportion open, enough to make tremendous noise). Then, under mainsail alone, I wanted to round her up into the wind to douse or at least reef the main. But she refused. I tried many times but she always came from a run only to a beam reach but I did'nt bring her into the wind. With the mainsail flogging, she still heeled so much that I did'nd dare to leave my position on the side deck for fear of capsizing. I tried to start the electric motor but its cable had wriggled loose and so it did'nt work. To get it running, I would have to open an inspection port in the cockpit and use both hands which seemed too dangerous in the given situation. So I had the choice of either running into port at planing speed, hoping to find calmer water and less wind and thus better maneuverability and at the same time fearing to hit something hard and expensive like a boat on a mooring - or otherwise drift sideways onto the shore. Then there was a crack and the rudder was broken. This left me (so I felt) without any choice. I was really scared. I had to actively convince myself that my life was not at risk but only my beloved boat. And all the emergency equippment that I have to carry along was absolutely useless. Now, even beeing scared, I am not the type to just do nothing. Since there was no rudder left to work with, I stood on the side deck, hooked my left arm around the windward shroud and, in between the gutst, reached with my right hand for the mainsail's tack and pulled for a few seconds. So very slowly, I got the mainsail down. Of course this did'nt prevent it from playing mischief - but it was mischief with little leverage and manageble. Now I could fix the motor and drive into port. When I had finally tied her up and fastened the sails, disaster made another attempt: I lost my mobile phone. I thougt, I couldnt even tell my wife - but then I found it lying on the jetty. Only then it occured to me, that I might have got her into the wind if I had dared to sheet in the main a little to give her enough drive against the chop to roud up. Who knows - maybe the old rudder would still be there by now. I went to a restaurant for dinner (as I always do on my cruises) and phoned my wife. The night was not quiet. Neither was the water nor the boat, let alone my soul. I thougt of motoring back (would there be enough power in the battery ?) or of several ways of repairing the rudder. The following mornig was calm and sunny and my mood had improved a lot. Of course, I would repair and proceed my jouney. As everyone knows, on an old wooden boat there must be a well filled tool box. But as everyone also knows, there isnt much space for tools on an old wooden and small boat. My solution is carrying smallish tools, partyl childrens tools (some of them are really from my childhood days). One is a egg-beater-style hand drill. With this, I drilled a new pivot hole in the broken rudder blade, having removed the small upper part, fixed the position with a bolt to prevent it from swinging up and a webbing strap to prevent it from swinging forward. And I was ready to go. Apart from the rudder, the jib was damaged too, so I changed to the genoa. Muckla behaved almost as normal with the smaller rudder and I went on cruising for the rest of the week. The repaired boat in Wasserburg-harbour The front before it reached me. Strangely, the gale-warning lights did not flash.
  6. Well, its been a while now..... Andy, I hope ,it is not too late for a thanks for your input. As for the amount of work, you're propably right. The glue-lines have actually been a great help in shaping the rudder - but then again the glassing took a lot of time.... As for the size - even this seems to lie in the eye of the beholder. At 124x30 cm it is a lot bigger than the dinghy rudders, I used to know before I bought this boat. By end of May, I finally launched her - only to discover that she leaked. Only a little but as we were about to go for a 2 weeks holiday on the island of Korsika this would have meant to leve her unattended in the water for 3 or 4 weeks. This seemed a little risky to me so I ground my teeth and took her the 2 hrs drive back home. The trip to Korsika was phantastic. The leak was between the stainless bushing of the CB-pivot (it has a flange) and the surrounding plywood. This spot had leaked before. I had tried to fix that with thikened epoxy but obviously this was'nt sufficient. Off course , the leak was somewhere close to the bottom plank where you can neither see nor work properly. I ground the tip of my welding hammer to a sharp point and used that to chip the epoxy away. There really was some kind of void - and there must have been a crack or so between steel and plywood. I applied "Capt Tolleys Creeping Crack Cure" (I love that name and the stuff too) and then epoxy again. All in all, it was'nt before middle of July before I finally had her in the water. Tight and with a new rudder blade. Short season this year. The rudder works fine. Only at some speeds it starts humming. I'm not quite sure if its grip is really better than the old ones when she heels over - but anyway in the gusts, I have encountered so far, the steering was perfect.
  7. Hi Randy, I'm using a Epropulsion Spirit. The older version with 1000Wh-battery. I like it very much and am glad that I bought it. As for the battery with its weight, I bought two special extenson cables (allthough they are very expensive) which enable me to put the battery in the cabin under the bunks. So it can fulfill its second job as part of the ballast - and it is out of view from possible thieves. The clamp-thing that normally holds the battery on top of the motor is covered by a wooden "hat" which also is the handle to tilt the motor upwards. For more details and pictures, you can look up a thread about electric motors in the Main Forum that ran from Sept 2019 to July 2020.
  8. Hi Chick, this looks really cute! Would you like, telling us a bit more about these mini-boats ? where and for what you plan to use them, what kind of motor etc? Stay healthy Tobias
  9. Slowly I'm getting on....... As for my initial question, the lateral form, I decided to give it a moderate elliptical shape. The additional area is in the lower half at the trailing edge. To compensate for the larger area aft, I put the semi circle (which is inside the rudder-head and includes the pivot) a little aft too. The result is that most of the rudder moves a tad forward , thus providing a little more balance. I hope that the sailing characteristics will remain the same all in all - apart from improved rudder-bite when heeled. Then I glued the two half-blanks together. When I took off the clamps, I found that the whole thing was bent....... Having done the necessary cursing, I did a lot more of shaping the profile plus straightening the whole thing, mostly by hand-planing, until it looked/felt good enough. I used a negative template for the NACA-profile. For attaching the haul up , I made a tag of copper and rivetet it to the trailing edge. Here is the dry fit with the old blade for comparison. (For whatever reason, I still can't fit a picture inside the text) Meanwhile, I epoxied and glassed the whole thing and put on two coats of primer. So its mostly ready.
  10. Peter, thanks for your reply and thoughts. As for the material, I had thought about that , but decided otherwise because building with solid staves is much more time consuming - and time is crucial for me ( I have to work a real lot). And then the old rudder blade had lasted for some 25 years, made of plywood and not glassed. So I hope that the new one will have sufficient strength when I glass it over and make a more gradual transition from the rectangular section which is inside the rudder head to the profiled main part which gets immersed. Thus creating less of a weak spot (where the old blade has broken as you can see on the photo). Cheers Tobias
  11. Hi everybody, Muckla needs a new rudder blade, the old one broke on my autumn-cruise (maybe I'll write down how and post it in the Boating and Cruising Stories). I bought marine ply and started building the new blade. Now that I've got to do that, I'd like to make a better one. This means a stronger onde above all - but at times, when she heeled, the old rudder lost its bite. I don't like to have a longer blade as this would give more leverage and thus a higher risk of braking again - but I think, it should have a greater area towards the lower end. As for the profile, I have setteled for NACA 0012 and even started ro route my half-blanks to that profile (see pic). But I am unsure about the shape (sidewise-view). The old blade has this elliptical shape which is said to have little drag. Any ideas about how much more drag I might get when I make a fatter ellipse or even a straight downward side like on the Lasers appendages? I recall having read a contribution of the late PAR about that, stating that the elliptical shape would'nt be that much better - but I can't find it any more. So who knows more??
  12. hi Sanmi, my boat is a 20 ft centerboarder with a small cabin. In case you want further information: I wrote more about her in the main forum in Jan. 2019. The extension cable comes only in 2 meter-lengths. First I bought one which allowed to stow the battery under the side deck near the forward end of the cockpit. Better than above the transom but I was'nt completely happy with that. So I bought another 2 m and now I keep it in the cabin, There is a doubble-berth going from side to side and the battery sits under that on top of the keelson, thus contributing to the ballast. The Epropulsion-battery is in fact easy to install (I think, its quite similar to Torqueedo), so keeping it at some convenient place and putting it on if necessary seems quite sensible to me.
  13. for my Epropulsion spirit, I bought an extension to move the battery and it’s weight more forward & downward. This works well - but a special cable with special connections is required and they are disgustingly expensive. As I definitely wanted to move that weight and didn’t dare to extend those nine pin cables myself, I dug into my wallet.... All in all, I‘m quite happy with the electric OB even though it has lately let me down due to a loose connection (which after all was my own fault)
  14. I may be late on this topic. Some time ago, I asked about using pure citric acid for cleaning epoxy. From the replies then, I gathered that it hasn’t been tried by many. So I gave it a go. Works fine for me, doesn’t stink and it’s cheaply available - here at least. It comes as a powder to be mixed with water. No idea if it penetrates the skin but it is definitely easy to wash away.
  15. Glad that it didnt turn out worse and glad you shared this story. This about forgetting things: When I bought Muckla, my Diabolo, in 2009, she was in the water. I had a cold but sunny week of autumn cruising on Chiemsee in her before I took her out of the water and brought her home. So pulling her out, unrigging and trailering was all new to me. I was amazed, how hard it was to winch her on the trailer until I heared a crack and realized that I had forgotten to hoist the CB up. So the first repair was due to stupidity. Lesson learned, I thought - until it happened again this year.... Mucklas CB does have a downhaul, which I reguarly forget to uncleat when I should. I am not shure if this could prevent the CB from falling back and damaging the CB-trunk if she really capsized - but that's the reason why I always cleat it. I hope, I can never report if it does.
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