Framing hulls

To the building process...

Building started in last week of July 2009. First some material was purchased, plywood and wood.
Plywood - exterior quality birch plywood:
1 sheet of 12mm / 1/2" thick 1220x2440 mm / 4' by 8' in size for ribs, rudder;
4 sheets of 4mm / about 3/8" thick 1250x2500 / 8'2" by 4'1" in size for planking, good because of the extended length of the hulls;
2 sheets of 6mm / 1/4" thick, 1220x2440 / 4' by 8' in size for decking, where more than half of one will be spillage   

Wood - I bought what available:
5 boards of 195x20mm / 7 3/4" by 3/4" spruce, 4500mm / 15' long (one for strongback, 1 for longitudinal beams, 2 1/2 for cross beams, 1/2 for front cross beam template, to be reused as tiller crossbar)
9 battens 40x20mm / 1 1/2" by 3/4", 5500mm / 18' long (2 for keels, 2 for inner battens, 1 for outer batten, 4 for sheer battens).

Some pieces of boards I already had, so first there was made a base (strongback) for assembling hulls. I made it as simple as possible, laid it to a more or less level garage floor. A straight center line was drawn by marking string.

Cross boards are screwed under each frame and to ends. To fix ribs/bulkheads, were screwed 6½” blocks, the respective ribs were then screwed to them.

NOTE! On ribs 1 & 2, from base line to the top measures 4¾” and on ribs 3 & 4 it measures 3”, so what I did was I raised the baseline from 3” to 4¾” from assembling base. Transom panel was cut just by base line and fastened similarly to rib A (only tilted).

As mentioned earlier - the boat was extended to 16 feet; therefore I wasn’t sure the double ribs would fit, so we assembled one of the pair, transom, keel and battens, then took new measurements for two other ribs. The height of rib A was just fitted to match between battens.

The keel was sawn to half as according to plans (a little longer) at the bow end for bending, used c-clamps for holding the form, used PU resin.

It is a good idea to make a hole or cut out a corner where ribs and keel meet - to allow water to drain to aft sections (if it ever gets in there) as the inspection hatch is in stern.

Used cargo straps to level up ribs where needed as on lower photo, there it is ready for planking...

Yes, yes... I know the garage floor is too clean, but it will change.

To cut plywood for planking the sheet was clamped to battens, the line was drawn from the backside by the batten and cut, then again clamped higher and line drawn by the keel and cut, rest of the sheet was for the rear part of the boat. The outer planking was cut in one piece; accordingly line was drawn by keel at once.

Then glue was applied and planking screwed to battens and keel, distance between screws approx 100 mm/ 4"

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