Use a small calking iron and mallet. To calk the lark will require a 1 pound roll of calking cotton. When calking, start at the end of a seam and calk in the end of the thread. Let the thread hang down from the seam, then gather up an inch or so of the thread and drive it in, slightly advancing along the seam ; this will show a fullness or loop of cotton that has not been driven in. This is so you can regulate the amount of cotton to the condition and opening of the seam by making the fullness of the loop as close as desired. After calking a few feet, go back over it again and drive it home Do not use too heavy a mallet or drive the cotton too hard; it is only necessary that it is firmly in place. As the plank are light, care will have to be taken not to get in too much cotton because after the boat is in the water, both the cotton and plank will swell. A little judgment will tell you how big a thread of cotton to use, and a little practice will show you. Fill the seams about two-thirds full of cotton.
When calking a seam that is tight on the outside, first, drive the iron along the seam to slightly open it before trying to calk in the cotton. First calk the butts between the ends of such streaks of planking as have been put on in two pieces, then calk the seams between the plank, calking the tightest seams first and leaving those that show the most opening to be calked last. The seam between the sides, ends and bottom is not calked. After boat is calked, smooth it down with sand paper and give outside a priming of white lead and oil, working it well into seams with a narrow seam brush. When dry, putty seams, butts and nail heads, and then give outside two more coats of paint. A good white paint is made by using equal parts of boiled oil and turpentine mixed with equal parts of white lead and zinc. The bottom of the boat may then be given a coat of copper paint, which will act as a preservative in hot water and also prevent the fouling of the hull by moss in fresh water. The coaming, fender-wales and deck, if not canvassed, should be fin-ashed in natural wood. First scrape smooth and sandpaper, putty all brad heads, then give three coats of spar varnish. When painting or varnishing let each •coat dry well before putting on the next.
The bottom of the cock-pit may be fitted with a tight floor of half-inch stuff or with open slats as shown in Fig. 8.
In the instructions for making the center-board, we told you to connect its after top edge with a chain. For this boat a chain is better than a rod for the reason that when the board is only half way down, the rod will be in the way of the boom swinging.
For the chain use a dog chain or any small chain that will allow of the spike being put through the links to hold the board in place.
Fit a cap on the top of the center-board box, letting it extend from the forward end back to within a couple of inches of the after end. (See Fig. 8.)
The dimensions of the spar, boom, gaff, sail, etc., are given in Fig. 10. To make the spar, take a square piece and dress down the corners until it is eight squared, that is, has eight instead of four equal surfaces. Then repeat the operation so as to give sixteen sides to the piece after which it may be easily planed and sandpapered perfectly round. Leave the spar the full size to within three feet of its top, the top three feet being tapered to half size. Make the boom and gaff in the same way. The jaws of the boom and gaff are made of oak and shaped as shown in Fig. 10. Bolt in place with 1/2 in. carriage bolts. Bore one 3/8 in. hole near the after end of the boom and gaff, and two holes hrough the jaws of each, close to the end of boom and gaff. These holes are to take the lacings that hold the sail at the corners.
Fasten the upper or peak halyard block to the spar with a 1/4 in. eye-bolt, locating this bolt six inches be-low the top of the spar. Fasten the lower or throat halyard block in the same way, one foot below the peak halyard block. Bore the holes for these eye-bolts so that the blocks will come on the after side of the spar. For mast stays, cut three pieces (legs) of 1/4 in. wire rope rigging 15 ft. long, and splice an eye in one end of each just large enough to go over the top of the spar. These eyes will slip down and rest on the eye-bolt that hold the peak halyard block.
The chain-plates are made from 1/4 in. band iron 1 in. wide, are fastened to the sides and end and hold the turn buckles as shown in Fig. 11. The chain plates should be 3 in. long with an eye at top to take bolt of turn-buckle. Drill and countersink four holes in each and fasten them in place with 1 1-8 in. No. 12 screws. The forward chain-plate is located at the center of the bow and the side chain plates are located at a point eight inches aft of the center of the spar.
Now, cut the hole in the deck for the spar. This hole is directly over the mast step so that the spar will stand plumb. A collar of oak may be put around the hole and screwed to the deck to reinforce it.
Set the spar in place and pass the three lower ends of the wire rigging through the top of the turnbuckles and seize the ends back to the standing part. By seizing is meant to wind a piece of string or marline about both parts.
Set up the turnbuckles so as to take out the slack, and bring the rigging down to place, after which it may be loosened and the lower ends spliced to place.