Stretching weston Farmers Sundance design and misc

Discussion in 'Boat Design' started by Delaney, Jan 22, 2009.

  1. Delaney
    Joined: Jan 2009
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    Location: South Carolina

    Delaney Junior Member

    I am very much interested in this design for use on moderate size inland lakes that sometimes get choppy. I love the older designs because they had great, to me at least, performance with low hp.:)

    :?: What I am wondering is the best way to stretch the hull. I know I can add a few inches between the frames, but I was thinking of adding another frame by just copying the transom frame again to make for a smooth flatter bottom at the end. This should give me the 18-24" I want for more fishing room. How practical is that idea?

    I know Tom L. used Sundance as an inspiration for his Bluejacket line so maybe he will chime in. I would also be interested on info on his 20' design, but cannot seem to find any links.

    My other question involves taking out the tumblehome. It seems like all I would have to do is straighten out the frame where it bends to equal other frames that are pushed out rather than in. I just think it would make it easier to build and easier to put a wider side deck on it. I woul give up some beauty, but oh well.

    :?: Also what are thoughts on powering with 2 - 15's or honda 9.9's that are really 13.5 hp. I like the idea of the duplication and it is quite possible that one motor would plane it loaded lightly. I also like to troll slowly and have the option of going in 10 hp lakes. The Suzuki 15 is based on the 9.9 and the only difference is one decal. My other option is the 25 hp efi Mercury/Nissan due to the high tech and mpg possibilities. Then I would go with troll-n-tabs with their joystick design. Any thoughts.

    Thanks for the helpl
     
  2. timothy22
    Joined: Feb 2008
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    Location: florida

    timothy22 Junior Member

    The tumblehome is not as much trouble as you may think in a small boat with thin planking. We had good results lengthening a Bertram 46' MY at a boatyard where I used to work. We had a naval architect validate our work, but all we ended up doing was using 2x6s to extend the hull lines aft about 6', adding a cockpit where there was none before. The Bertram was significantly faster and rode much more level. So what you suggest is doable, but with all the small boat designs (and designers) out there, why take a risk you don't have to? If you must have a Sundance, at least have a designer have a look at the plans before you build.
     
  3. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    I saw the Weston Farmer name in your post and, since he is a favorite of mine I looked further. There is just not enough time to read everything on the forums.

    I saw my first live Sundance at the Georgetown , SC Woodenboat show last October. Not the greatest construction skill shown, but it still looked really nice. I see no serious problem issue with stretching the Sundance a bit just like you mentioned. My boats were inspired by the style of this design but are not based on it and are quite different. Being much larger, they can offer quite a bit more in the way of accommodations.

    If you only want perhaps 2' more length, you can just add a proportionate amount to each station space and have no fear that the boat will come to harm from that.

    I am less enthusiastic about the Bluejacket 20 than the other boats in the series because it was done on the cuff, so to speak, to satisfy a determined client but never actually built it. It would most likely be fine for sheltered water but fatter than I would like for other use. There are other boats with similar dimensions so it is probably OK.

    What you want to do in extending the boat for a larger cockpit is not too difficult but not in the way you want to do it. It can be done but will reduce the transom beam and make the larger engine or two engines more problematic. Stretching the station spacing and relocating the interior to add the extra room in the cockpit would be better. I prefer a single engine and smaller kicker if that is required. New outboards are very reliable and neither I nor others I know have had significant problems with getting stuck and not able to get home.
     
  4. Delaney
    Joined: Jan 2009
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    Location: South Carolina

    Delaney Junior Member

    A quick question on the stretching:?: . Is it as simple as adding the extra length to the frames that are behind the first frame where the curvature of the bow stops? Can it be to just the last last few frames where the bottom is fairly flat or is the extra all the way through front to back.

    Is there a definitive thread or book to get on this idea that i could look up or buy. Seems like we always want to change something doesn't. I guess that is just boat building:D
     
  5. eponodyne
    Joined: Aug 2007
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    eponodyne Senior Member

    OH MY GOD!! Thanks for this thread. I have been wondering the same thing myself.

    Actually, no. What I want is probably an entirely different boat, but the same thing: What I want is something *just halfway* between
    [​IMG]
    SUNDANCE

    at 17'3" by just 6' of beam, and drawing (motor down) about 1'3"; designed to run nicely with 25 Hp at 20-25 MPH.

    and

    [​IMG]
    HAVEN, by Atkin & CO.

    Runs to 29'9", 8' even across the wide spot, designed draft of 1'10". Mr Atkin the Elder claimed that 175 h.p. at 3600 r.p.m. from a 372 cubic inches Graymarine--and would that have been a Straight 8, I wonder? --should give a top end of 35 miles an hour, perhaps a little better.

    He called HAVEN a "rough-water rescue boat" and the huskiness with which it was designed makes me think he fully pictured a boatload of men with rifles returning fire in six-foot seas at speed. Certainly it looks like a flush-decker half-scale PT boat.

    Underwater, the boats are similar in their forward sections,

    [​IMG]
    SUNDANCE here , very graceful;


    and

    [​IMG]
    Haven.




    What would you call something in between those two beauties?

    SUNHAVEN.



    So I guess I'm looking for a raised-decker with these general proportions--and the boats are somewhat similar in terms of springiness of sheer, length of foredeck, size of cockpit, height of freeboard-- running twenty-three by seven foot. Keep the tumblehome. Hell, give it even a little more, like on a Lyman Islander. If nothing else it does reduce the size of your transom, saves a little weight, and always looks pretty. Windshield-on-a-box like SUNDANCE has isn't terrible but there's probably a better-looking way to go about it.

    It'd be nice to keep the build options open-- ply on frame has its limits, but they've been stretched considerably in the 60 years since HAVEN was first drawn. Cold-moulding, strip-plank composite, batten-seam all could probably work just fine, and if you had a serious boner for lapstrake, I imagine it wouldn't be that hard to do either.

    There've been a lot of boats built in this size range, coming in right around a ton or so. Lots of them get a lot heavier pretty quickly. And any idiot can stuff a hull full of horsepower and make it go fast, but to be able to move 25 mph on 25 HP, like SUNDANCE? That's pretty damn cool. That also works out to something like 12 MPG from a Honda OB, which is nothing to sneeze at. Power SUNHAVEN with like twin 50-hp engines, and I bet a person could get within striking distance of that figure if one kept the heaviness out.


    Interstingly, this brings us right around toward the dear old Option One concept.
     
  6. tom28571
    Joined: Dec 2001
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    tom28571 Senior Member

    These boats that eponodyne shows have very little in common other than being boats. I suggest that you define what you want in a boat and then find a plan that corresponds.

    Just buying a boat requires some study. Picking a plan based on its lines and specifications requires much more. Many will pick a boat based on a favorable first impression based on looks alone. Many pick a spouse that same way. Both are most often disappointed.
     
  7. Delaney
    Joined: Jan 2009
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    Location: South Carolina

    Delaney Junior Member

    :confused: So Tom you think it would be as easy as just adding 2 inches extra between the frames and doing a straight build. That would give me about a foot and half extra which would be great. Would I add 2 inches to all frames even the first one since it is so short. Thanks for any help
     

  8. tom28571
    Joined: Dec 2001
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    Location: Oriental, NC

    tom28571 Senior Member

    No you can't do that. It would make for very unfair lines anywhere the frames are not evenly spaced. If you can scan and email the frame spacing to me I will be glad to do it for you.
     
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