Archive for the ‘Pram’ Category

How to Fit the Keel to the Bottom of a Nutshell Pram

Friday, November 6th, 2009

I was recently ask how to fit the keel to the bottom of a nutshell pram. There are several ways to fit the keel. Here is the way that I did it when building my nutshell.

  1. Clamp a stick 1×2 3 feet long to the transom so that one edge is at the centerline of the boat and sticks up over the bottom by 6 inches or so.
  2. You will need a piece of plywood or cardboard about 8 inches wide by 6 feet long, this will become the pattern for the keel.
  3. Clamp the pattern to the stick so that it is on the centerline of the boat.
  4. Decide where the keel will begin and make a mark on the boat.
  5. The pattern should touch the boat at about the patterns center with equal gap at the transom and where you made the mark.
  6. Tape some blocks to the boat and the pattern so that the pattern is reasonably supported.
  7. You will need a block of wood that is taller that the gap at the beginning and end of the keel.
  8. With a pen or pencil supported on the block, mark the contour of the bottom to the pattern.
  9. Remove the pattern and cut out just shy of the line.
  10. Place the pattern back on the boat as see if you have any high or low spots.
  11. Remove material until the gaps are less than 1/8 inch. Less than a 1/16 is better.
  12. Mark the outline of the keel to the pattern and cut it out also.
  13. Use the pattern to mark the Oak and cut out the keel.
  14. Place the keel on the boat an look for any high and low spots. Again 1/8 of an inch is ok but 1/16 is better.
  15. My preference is not to use hard epoxy to attach the keel to the boat. I have used 3M 5200 but something like G-Flex would work also. You want something that has a little give to absorb shocks.
  16. Drill from inside the boat into the keel for bronze screws to hold the keel in place while the 5200 cures and the screws also give extra strength to supporting the keel.

You will may want to trim off the extra 5200 and attach brass half round to protect the keel when beaching. The whole process is fairly simple and straightforward.

Randy is Building a Boat

Monday, November 12th, 2007

I am starting to build another boat. The first boat I built was the Nutshell Pram designed by Joel White. This time I will be building the Willy Winship, a 13′ 9″ sailing skiff designed by John Atkins. This boat can be rowed, sailed or powered by a small outboard motor. The method of construction will be the same as the Nutshell Pram, glued plywood lapstrake.

Some of the skills I plan to learn or improve are scarfing, lofting and lining off planks. Lofting is drawing the boat full scale. This will be done on a 4′ x 8′ 1/4 thick plywood painted white. For this design, only the bow stem and stern need to be lofted and once drawn they will be used to transfer to the White Oak that the bow stem and stern will be made out of. I am using White Oak for the stern, bow stem, skeg and guard rails. White Oak is heavy but also is very strong and robust.

I plan on providing descriptions and explanations as the boat construction progresses which may be technical and terse. If you find that you don’t understand someone thing please post a comment and I will try to provide more information.