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Re: Strip: Strip start help
By:Paul G. Jacobson
Date: 2/21/2010, 8:56 am
In Response To: Re: Strip: Strip start help (r-ice)

: I probably should've said which boat im interested in. I believe I
: should start with the great auk. I did read the lofting part and
: I still am not sure exactly how to do it. Maybe if I purchase
: the plans and once I see what I was supposed to get, maybe i'll
: understand it then.

There are several frames for most boats. Concentrate on one frame at a time. The table of offsets gives the points that you draw on graph paper to give you the outline of the frame you will build. Most of the time these points will give just one side of the frame. The frames are symmetrical, so just plot the same points To get a mirror image.

It is pretty much like drawing a graph in High School geometry class. With small boats you get measurements a certain distance either above the keel or above and below the waterline. The table will say how far apart those lines are. Usually they are 2 inches apart, but some designers make them only an inch apart, and for bigger boats they may be 4 inches apart or more. If you have plain paper, draw horizontal, parallel lines on it spaced just as far apart. Draw in a vertical line, and use a ruler to measure along any of these. The table tells you how far you go from the center line. Usually these measurements are listed in feet (') inches (") and eighths of an inch, If it is more than exactly an eighth, there will be a plus sign(+). So a boat which is going to be 23 1/2" wide at the waterline will have an entry in the table of offsets of half that, or 0,11,4.

There may be different punctuation between the numbers, but what I've shown would be zero feet, 11 inches, and 4 eighths. Plot that to the left and right side of the center line and you would get a distance between these points of 23 inches. This is not the width of the boat! The frames are designed to be smaller. When you add 1/4-inch-thick-strips to the outside of these frames the width increases to what the designed intended.

If that last number is over 8 anywhere on the table of offsets you'll know the designer is measuring in inches and sixteenths. Sometimes they do that for extreme precision, but it can be confusing to some.

After you have marked the measurement for one spot on a line parallel to the water line, go to the next one, and mark its point. Continue until you have marked all the points for that frame. Now you have to connect the points. In some cases it is a simple matter to draw a straight line from point to point. That is more common for boats built with plywood. When building with strips you will want a rounded hull shape, so you need to draw a smooth curve which connects all the points. Get a thin, flexible strip of illustration board, cardboard, plastic, metal, wood or plywood. Also get a friend to bend this so it hits all the points. Have the friend hold that in place while you trace around it with a sharp pencil. You now have an outline of your form.

To avoid all this, you pay money to the designer and have them send you full-size pictures of each form, (patterns) which you can glue to your wood and just cut out.

Plans show pictures of the finished boats with minimal details. Offsets are a stack of numbers which provide the details. Patterns are a stack of big sheets of paper, Kits are stacks of precut wood. Generally speaking, the further you go down this chain the less work you have to do, and the more you pay. You pick a point at which you are the most comfortable, based on the size of your wallet and your skills.

Hope this helps. Good luck to you in your project.

PGJ

Messages In This Thread

Strip: Strip start help
r-ice -- 2/10/2010, 10:38 pm
Re: Strip: Strip start help
Ian johnson -- 2/11/2010, 5:14 am
Re: Strip: Strip start help
Bill Hamm -- 2/11/2010, 2:54 pm
Re: Strip: Strip start help
Ian Johnson -- 2/11/2010, 3:49 pm
Re: Strip: Strip start help
Will N to Go -- 2/11/2010, 9:24 am
Re: Strip: Strip start help *PIC*
Shawn -- 2/11/2010, 1:36 am
Re: Strip: Strip start help
Bill Hamm -- 2/11/2010, 1:02 am
Re: Strip: Strip start help
george jung -- 2/10/2010, 11:12 pm
Re: Strip: Strip start help
r-ice -- 2/10/2010, 11:21 pm
Re: Strip: Strip start help
Paul G. Jacobson -- 2/21/2010, 8:56 am
Re: Strip: Strip start help
Bill Hamm -- 2/11/2010, 1:05 am