Kurt Hughes Daycharter 36

Discussion in 'Boatbuilding' started by Charly, Mar 10, 2010.

  1. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    Hey guys, here are a couple more pics of the keel and the fold-up.

    My day job work schedule has been interfearing with things. I am only able to manage an hour or two a day during weekdays. The fold-up is not complete-- I still have about four to six inches to go, thwartships.

    I am having a few issues, nothing serious I don't think, but I am curious to hear from others who may have already "been there, and done that".

    First, notice the stem, in the pic. I have a plumb bob in the foreground, a bit hard to see, but the forefoot is clearly out of whack. The panels did not mate up perfectly at the bow, off by about 3/4 of an inch, and the whole thing is asymettrical. I am wondering if the patch I did on the stb panel made it behave differently, Did anyone else have this problem? I think I will try and twist the whole hull, once I succeed in anchoring the after part down. If that doesn't help, I don't know what else to do but get out the grinder, and try and re-shape the thing. The radius cut at the forefoot and the top of the stem should make it look better also.

    Speaking of the stem, The plans call for a foam/plywood sandwich, and I don't have any foam, but I do have some WR Cedar. What about a Cedar sandwich? I don't fully understand the purpose of the stem. Others have mentioned going "stemless" and just bogging and glassing the crack. Any opinions?

    Finally, the Transom. The plans call for laying in the keelson, but stopping short a few feet at both the bow and the stern, to facilitate the fold up, then coming back afterwards and finishing up. I may have messed up here. During lace-up, i did not lace the keel up tight all the way to the end. I only laced the thing up as far as I needed to to lay the keelson. The picture shows the keel is still unlaced by a couple of inches at the very end. I have come back now to try and lace it up tight, but only gained a fraction of an inch on it. I even tried putting a bar clamp on the thing, but it won't move. Granted, this section will be cut out anyway for the rudder housing, but I am wondering if there is something I have not thought about here.

    I really appreciate any and all critisisms or advice.
     

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  2. eladio
    Joined: Sep 2010
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    Location: ARGENTINA

    eladio trimaran...

    Hi Charlie, I follow your project closely.
    I think two things:
    1-No symmetry can be the difference in stiffness between the two panels (half hull). Maybe someone is weaker than the other. The reason may be the failure of adhesion between the ply. Or repair'm more thick, and that the stiffness change.

    2-wire joints keel, the hull was in a position different from that shown in this graph, adding a lot of tension in wire joits, and was opened where it was not tight.
    "Look at this graphic. Draw Nº4.
    http://www.multihulldesigns.com/pdf/cm/CYLINDER MOLD MULTIHULL CONSTRUCTION.htm

    Now it will be very difficult to close, by the rigidity of the keel.

    I think you should talk to Kurt ...


    Eladio
     
  3. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    Thanks eladio.

    I have an e-mail in to Kurt. I spent all day yesterday messing with it, getting the deck clamp positioned, leveling, tweaking and verifying everything else. In the process, I discovered a split down low on the port side, opposite the hard spot on the starboard. There was a void there as well, that I did not catch beforehand. SO, the more I think about it, I am coming to the conclusion that the only thing to do is to spread the hull back out and repair the new split. This should stiffen up the port side considerably, and hopefully it will then match the starboard, and help with the symmetry. This will mean an extra day or two of work, but heck... and all in all, I am pleased so far.

    It sure is butt ugly right now though :)
     
  4. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    bow unlaced. There is a plumb bob in the foreground, just behind the stem, and another one, harder to see, at the transom end. (yikes)
     

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  5. eladio
    Joined: Sep 2010
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    eladio trimaran...

    Hello Charly, a difference seems to be so stiff, then you should "torturing" a little to put in place, and after that repair.
    Maybe you should put some auxiliary bulkhead and the outer shape of the deck, to put in place.

    I'm learning a lot from your work.
     
  6. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    update:

    Well, I undid everything, and spread the hull sides back out. Also unlaced the stem. Repaired the split on the port side with a scarf patch, and built up a plumb, "false stem" out of a straight piece of pine,that sat on the floor, and that was reinforced athwartships with a sheet of osb-- something stiff to hold the stem area vertical during the foldup. It worked great until the port panel split again.:( This time from the stem all the way back to the fourth station (about eight feet) The scarf patch I had just put in held fine... this break is higher up, and along about the junction of the keel cove and the topsides. After a fit of cursing, a mild case of shock and a couple of glasses of wine, I am over it now:). As I see it, there is nothing else to do but to open the damn thing back up for the third time, repair the mess (I'll have some gory pics to post next week when I get to my office computer), grind down some of the keel cove/topsides junction area to take some of the resitance out of the foldup, say a little prayer, and crank the thing together one more time...

    comments and advice welcomed
     
  7. eladio
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    eladio trimaran...

    Charly, in building the spirit is all!, We await the results of repair! I am an engineer, and every day must be fought with the buildings and builders ...
    Much encouragement
     
  8. Charly
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    Location: st simons island ga

    Charly Senior Member

    Thank you eladio for the encouragement.

    I have decided this time to leave the split, without a permanent repair...and only to put some glass cloth ahead of it to stop its progress. I have ground out some of the roving from inside the forefoot area, to take some of the stiffness out of the ply at the turn of the bilge. and put a "splint" across the crack at the bow area, by using two short two by fours, one inside, and one outside, secured by temporary through-bolts.

    I have folded the sides again, to their final position, without anymore cracks this time. Oddly, the stem area is now more or less plumb. I have not finished triangulating the hull panels, to keep the centerline equidistant, but so far that has not been a problem... I will know more tomorrow. One side, however, is slightly lower than the other. Kurt's instructions say that keeping the centerline centered is most important-- the respective heights of the sheer timbers can be finessed later.

    My game plan now is to finish tweaking the hull tomorrow, securely fasten it into place in its cradle, install the stem, grind out and repair the split, and then get back on track with measuring and cutting the bulkheads...

    Any advice or comments welcomed
     
  9. Zebrausa
    Joined: Oct 2010
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    Location: San Jose, CA

    Zebrausa New Member

    Very impressed

    Hi Charly, I have learned so much from your posts. You are a true inspiration to present and future boatbuilders. Keep your posts about your challenges and problem solving fixes coming. You have one of the best threads on this forum!
     
  10. CatBuilder

    CatBuilder Previous Member

    Charly,

    The splits are one of the (many) reasons I abandoned my build. Some of my hull panels split while we were moving them (at the very ends only). Discussing the splits with Kurt, his advice to me was to use glass "band aids" to keep splits from happening and to stop a split in its tracks if it does happen.

    My panels also started to collapse within about a week of sitting against the wall in a C shape. The curve down by the bilge got sharper and sharper.

    Hey, did you remember to put glass band aids in all the places he suggests for fold up, such as up by the bows? Just checking to be sure.

    Anyway, best of luck with everything. I hope things get a little easier for you. You are taking this all very well. You are a more even-keeled person than I. Kudos to you for sticking to it and taking it in stride.
     
  11. Charly
    Joined: Dec 2009
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    Charly Senior Member

    I cannot thank you all enough for the kind words, advice and encouragement. These latest episodes have been very frustrating, and your positive comments are very refreshing.

    Yesterday I spent several hours, until well after dark, securing the hull, centering, checking alignment, and folding in the sides to their exact lofted dimensions. Everything looked great, with the exception of the uneven sheer height, which I am resigned to to leaving alone until the deck clamp comes off, and of course the nasty gash in the bow, which is now at least stablized.

    My wife was first to leave the house first this am. The hull is sitting in her parking space in the garage, and she must pass right by it to get to her car, which is now parked outside. (she has been great btw, since the onset of the "fever" a few years ago :) ... don't even try to build a boat without TOTAL domestic clearance) As I am pouring coffee I heard her coming hesitantly back up the stairs. Uh oh.

    The good news is that the latest split is mostly confined to that runwild section of the panel that will be cut out anyway, and it is now unfolded and secured with a piece of biax. I hope to fold it back up tomorrow and start the bulkheads this weekend. The latest pictures are almost too embarassing to post. The whole project looks like hell at this point. I'll get some up soon, I guess . My antiquated camera won't post pictures on my new computer here at home-- I have to go in to the office to do it, and I have been too busy catching up at work to put them up.

    Why all this trouble? At this point, I believe that most of my problems can be attributed to the stiffness of the 3mm BS 1088 Okume, on the biaxial mold. The designer has commented that it is much more important to produce a void free panel, than it is to produce a biaxial hull panel. Eliminating the biaxial part of the mold set-up, would eliminate a lot of headaches for anyone using Okume 1088 3mm plys, because there would be much less liklihood of voids, especially in the sections near the ends. The real problem for home-builders like myself, who are likely first-timers to this kind of build, is that due to the scarcity of this kind of plywood product on the market, the uncertainty factor of quality, the bewildering jargon about glues and stamps-- heck, its a pig-in-a-poke anyway. I had no clue, when I bought my plywood, whether it was too stiff, too limber, etc. It is impossible to tell unless you have done a cylinder moulding already. All I knew to do was just to buy it from a supplier that seemed reputable. It was hard enough just to find any in stock.
    So, I would advise anyone contemplating this kind of build to not use the biaxial mold, unless you had someone on-site with expertise, in cylinder moulding, or had a close hand-holding session with the designer, or both.

    The other thing is void vigilance. Much of my troubles would have probably been avoided If I had really taken the time to thoroughly tap every square inch of both sides of both panels , and fill any and every void thoroughly thoroughly.

    I used a light store-bought cloth for my band-aids on the stem, forefoot, and runwild section of the transom, just because I happened to have it. Mistake. My panel split right through it. Next time it will be 17 0z biax tape, made pretty with peel ply.

    Sorry for the long post
     
  12. CatBuilder

    CatBuilder Previous Member

    Keep at it, Charly. It sounds like you are at least passing some of the worst parts.

    I am restarting my Hughes build - from scratch - using foam/glass. Splitting wood has been a problem my entire life when I attempt to work with the stuff. I'm more comfortable in plastics.

    Were most of your splits at the ends as well? Mine were all at the very ends of the panels.

    Keep in touch with Kurt. He is helpful when problems come up. He's even sending me new plans (the foam/glass version). He's a great resource when you're building.
     
  13. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    thanks catbuilder,

    I had three splits during foldup. The first one was forward, and opposite side of the scarph patch that I did when the vertical break happened when we moved the panel from the mould (seems now like ancient history) There was a small void section there that I did not fix properly before hand, and the weak spot is where the split happened.

    The second occurred after I unfolded, re-spread the panels, and and scarph patched the first. It was a nasty break from the stem , just above the water line, and about six feet long. I had put in a two by four block at the stem, which was re-inforced and made plumb with a "false stem" out of plywood that was braced athwartships-- I was trying to fold the thing back up, and have the panels meet in the middle properly at the stem. I used a lot of force with a bar clamp, and... boom. ... OK, so other than go through another unfolding, this time I just put a splint on it . The bow is now plumb, the first station is still a bit out of whack, but I can fair it out with bog, etc.

    Ther third split was at the transom end, and happened sometime in the night after the last foldup. I unfolded and repaired it, now all is OK. The last two splits were in solid wood- no voids. whew. makes me tired just recounting it all
     
  14. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    Here are some shots of the stem. I have now removed the splint from the split at the bow , and will finish fairing the inside, with bog, scarfed ply, and biax. When I am able to access the outside more easily, I will fair it as well.

    All in all, I think things are going pretty well.At least, now when folks stop by, they say "Ah, you are building a boooat" :)
    My biggest concern at this point is the difference in height of the sheers (more than an inch in places) I guess I will have to shim one side and plane the other a bit. I have laid out the bulkheads, though, and they are all more or less symettrical.

    Oh and one more thing. The topsides are supposed to be flat. My hull has a very slight flare in some places. Has anyone else had that? I thought about putting a thwart brace inside, with some temp "stringers" to try and pooch it out a little. It looks like its gonna be another week or so before I can glass in the bulkheads. Has anyone else done that?

    comments welcome.
     

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  15. eladio
    Joined: Sep 2010
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    Location: ARGENTINA

    eladio trimaran...

    Hi Charly!
    your work is excellent! going over obstacles, and providing solutions to every problem.

    I think your solution to these problems with the waterline is right. Large surfaces of the ply, should be molded with a little force, strigers, and bulkheads. Everything is under tension, and there is much deformation.
    I assure you that I have thoroughly studied this system and see that it is not as easy as it seems

    Really follow your project closely, because I was in doubt with the cylinder mold. I saw a man who attempted to build a charter cat 45 ', and had almost the same problems as you, but abandoned. I thought at times I could not do it.
    I'll buy the PLANS for a 40'trimaran (Mad Dogs, is the same video system), and your experience and how you shared with us, gave me the courage to think I could do it.

    Put more general photos of your project, not only the problem areas!
    Greetings!
     
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