Help - Need a good pram plan

Discussion in 'Boat Design' started by terry32506, Jan 2, 2010.

  1. terry32506
    Joined: Jun 2009
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    Location: British Columbia

    terry32506 Junior Member

    Hello all...I have attached a photo of a pram thats based on some plans that I purchased. I like this style of boat but would also prefer it to have a back seat ( bench ) and perhaps a front seat as well. The plans for this boat are full of errors and some of the methods that are being done just dont seem the be right. For example to determine the bottom panel you have to use a single spreader across the middle of the side panels then flip the boat over and lay your ply on and trace that out to get your bottom piece...Trying to square the boat is a major headache. the left and right panels, front a back are cut according to the dimensions and still have problems getting it straight. Maybe its an angle error in the dimensions, I dont know but to me it would make more sense to have two more spreaders one for the front and one back to stablize it and not go out of kilt. I hope there are other ways around that method to putting a pram together. I would like to be able to cut the bottom panel out based on a dimension not by tracing if thats possible?. If so then I need a decent pram 8' plan but to be flat bottomed, not one of those V bottom prams which I have seen about all of whats out there and there are many. Its been a hard find to find a good one thats flat bottom requiring 2, not 3 sheets of ply and that has full size plans. Does anyone have any plans of this description or perhaps know of a reputable designer that could make them?

    All of your input will be greatly appreciated.


    Thank you,


    regards,


    Terry




    [​IMG]
     
  2. apex1

    apex1 Guest

  3. terry32506
    Joined: Jun 2009
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    terry32506 Junior Member

    Thanks Apex1 I have been to those sights. Do you know if either or these sites will custom make plans?
     
  4. apex1

    apex1 Guest

    No idea, sorry.
     
  5. troy2000
    Joined: Nov 2009
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    troy2000 Senior Member

    Mark the center of each transom on the outside at the bottom, and mark a center line down the bottom plywood with a chalk line or straight edge. Turn the boat over, lay the plywood on the boat with the line down.

    Put a factory edge of the plywood flush with the edge of the stern transom, with the plywood center line on the center mark of the transom, and tack the plywood in the center with a small nail. Then make sure it's lined up and flush with the transom all the way, and tack it with a nail at each corner.

    After that, line up the center mark of the forward transom with the plywood center line, and tack the plywood there too.

    If your sides and transoms were cut properly, you can't help but be square. Run a pencil around and mark the bottom well, take it off and cut it a tad big. For the final assembly make sure you put things back together with the nails in the same nail holes; that's easier to do if you have them sticking out about an eighth inch or so. After the bottom is permanently attached you can plane, rasp or sand it flush with the sides and transom.
     
  6. terry32506
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    terry32506 Junior Member

    Thanks for the tip Troy I will give that a try and see if all goes properly.

    P.S. Troy does the spreader play a critical part in this? The measurements for the spreader is 45" across at the top x 35 3/4" at the bottom. I notched out some on the bottom so that I could fillet and fiberglass the entire inside seems without removing the spreader. Does the spreader need to be exactly across the middle 48"? The plan doesnt say where but appears to be slightly back from the center mark. Does the dimensions sound right?
     
  7. troy2000
    Joined: Nov 2009
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    troy2000 Senior Member

    The exact dimensions aren't critical, since you're cutting and fitting the bottom to the boat, however it winds up shaped. What matters is that the spreader be symmetrical: If you have a center line down the middle, it needs to be exactly the same on either side, and fastened at exactly the same place to either side.

    And you can put benches or thwarts fore and aft if you want. But in a boat this size, you're better off keeping the weight in the middle. It looks like a very nice little boat, but it is little. If you put someone at one end, someone may need to sit at the other end.

    But what the heck: build 'em in if you want. If nothing else, it gives you somewhere to set your tackle box, and to fold and lay your jacket out of the bilge water. And if you box them in, you can add flotation.
     
  8. terry32506
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    terry32506 Junior Member

    Thanks again Troy , your advice has been great and now have much more to work with.
     
  9. cameron.d.mm
    Joined: Mar 2009
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    Location: Ontario, Canada

    cameron.d.mm Junior Member

    If you aren't sure about positioning of the seats, why not build a seat that is a bench stretching from one end of the boat to the other? It might look odd at first, but is works great in small boats. You'll be able to trim fore to aft by sliding a few inches either way no matter the situation or load. I did this recently in my small boat, and it works great.

    If you do build a length wise seat, make sure to still add some kind of spreader or spacer width wise, as it appears your plans call for it.
     
  10. terry32506
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    terry32506 Junior Member

    Hi Cameron , The positioning of the center seat does show where it goes, slightly behind the center point towards the stern and is held up with Battens 2 vertical and one horizontal as shown in the photo. When I get to that stage I may just add another for the back and leave the front open. This type of pram will be used for fly fishing hence why I am building a flat bottom style.
     
  11. cameron.d.mm
    Joined: Mar 2009
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    cameron.d.mm Junior Member

    Oops, poor wording on my part. All I was trying to say is that if you are considering adjusting the seating away from the stock arrangement, a single bench seat the length of the boat covers all your bases (except going seatless).

    Here is a picutre of what I meant. (not my boat)
    [​IMG]
    From the page http://koti.kapsi.fi/hvartial/dinghy1/simboii.htm
    If you are looking for plans, the above site has several that look like what you've got.
     
  12. jim lee
    Joined: Feb 2007
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    Location: Anacortes, WA

    jim lee Senior Member

    How about this?

    [​IMG]

    8 foot, flat bottom. About 70 lbs or so.

    I see your in BC so you may be close by. Make you a deal, you pick it up and you can have the molds, templates and all the tooling to make them. Free.

    I need to get this stuff moved to make room for the Dart production.

    Here's the story on developing the pram tooling.

    http://www.leftcoast.biz/iWeb/Left_Coast/The_pram/The_pram.html


    -jim lee
     
  13. terry32506
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    terry32506 Junior Member

    Hi Jim, sent you a message regarding your offer.
     
  14. keith66
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    keith66 Senior Member


  15. terry32506
    Joined: Jun 2009
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    Location: British Columbia

    terry32506 Junior Member

    Thanks Keith I will have a look at that.
     
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