Mark Smaalders Yacht Designs
prospective builders express concern about their
building skills. My cruising boats feature
round-bilge hulls that require lofting, careful
setup, and attention to fairness throughout the
building process. But one need not be a master
craftsman, furniture builder, or a wizard with your
hands to build one; any reasonably handy person can
build a boat.
drawn my plans to simplify the building process as
much as possible, and modern adhesives -- epoxy in
particular -- make perfect fits less critical in
many areas. Lots of builders learn as they go, and
there are many good books available to help you
through the hard parts. Building a boat -- and
developing confidence in your abilities and skills
-- is a very satisfying process.
buoyancy gain depends really on the wood species
you're using. Sea water weighs 64 lbs /cu.ft., and
adding underwater volume with something that weighs
less results in a net gain in buoyancy. For example,
red cedar is about 23 lbs/cu ft, d. fir 32-36 lbs,
etc. Naturally, you're also veneering the topsides,
which is strictly a matter of adding weight (not
offset by added buoyancy), and then there's the
weight of the epoxy. The overall result is
beneficial buoyancy-wise with lighter woods (such as
red cedar), and moves into the negative column with
woods above about 30 lbs/cu.ft. Red cedar is a fine
choice and often available in veneer, yellow cedar
(about 27 lbs/cu ft) is also good, or you may have a
local wood that fits the bill.
Q. I doubt if I can get anything except western red cedar for the veneers. Any problems with such a soft wood on the exterior?
No problem, especially if you sheath the hull with cloth. I prefer Dynel or Xynole polyester to fiberglass because of their higher flexibility and greater abrasion resistance.
Q. Do you suggest a bead & cove for the strip planking around the bilge. In strip planking would staples delivered from a pneumatic stapler work as well as nails?
Bead and cove strips can help in fitting the strips, though thickened epoxy will easily deal with small gaps. The strip planks could be stapled (in essence the fasteners are there only to keep things in place until the glue dries), though if the hull was ever damaged and water did penetrate the epoxy, you might have trouble with steel staples. I specify bronze ring nails because they'll be there for the life of the boat, no matter what happens. Also, they provide excellent holding power.
Q. How accurate does the lofting have to be?
Small errors (1/8" to 3/16") won't make any difference to performance. They may be noticable visually, but this can be dealt with (especially the topsides) if you're careful about fairing up the molds after setup, but before planking. There is also another chance to fair things after the hull is planked.
Q. I am still having much trouble with the lofting of the transom in regards to planking thickness deductions. Have tried all methods. I have added waterlines to assist but still does not work out. Must I add extra buttocks in this region?
Extra buttocks can help with planking thickness, in that the more lines you have that are nearly normal to the hull surface, the better off you are. But extra butts and waterlines may be most helpful in making sure you have an accurate shape. Deduct planking thickness using whichever lines are most nearly normal to the raked transom.