Back in 1940, the boating editor of Mechanix Illustrated undertook to design and build a boat to meet the re­quirements of a majority of readers. It seems that practically everybody wanted a boat with an engine and a vast majority liked sailing, so it was quickly settled that the boat should have both sail and power.

Then, too, most people wanted a boat of moderate size and ample beam with a roomy cockpit for fishing and a comfort­able cabin for overnight trips; shallow draft was desired, so that a dinghy would not be needed and the boat might be beached if necessary; V-bottom hulls were first choice because of their seaworthiness and ease of construction; a fair turn of speed was wanted, both under sail and power; and last, but far from least, the boat had to be well built at moderate cost. How well the designer met the requirements is evidenced by the continued popularity of the original Bonnie.

Some fourteen years later, Dick Dono-hue, of Seattle, Wash., bought a set of plans. Before he got around to building, he had the opportunity to buy a second-hand set of sails, mast, boom and rigging from a Mercury Class boat. Knowing that Bonnie's sail area, about 165 sq. ft., was very close to that of a Mercury, he decided that with some careful figuring he could adapt the plans and come up with a workable design. Other changes were incorporated, mostly because of a desire to reduce the costs even more than in the original Bonnie. The re­sult, a lighter boat with a new sail plan, which was built for the low cost of $403, is now presented anew as Bonnie II.

This sturdy,   18-foot auxiliary sloop features seaworthiness and comfort.

The first step is to cut three 20-foot pieces from a roll of building paper, lay the pieces flat on the floor and paste them to­gether with rubber cement or other adhe­sive to make one large sheet 20 by about 8½ feet. Paste up another sheet to a 5x8-foot size. Spread out these big sheets on the floor and hold down the edges with anything handy. With a chalked string, snap down centerlines and- base lines and accurately transfer the profile to the larger of the two sheets—the body plan to the smaller.   A long, straight rule, a couple of flexible battens and a black pencil will be needed for this. Measure off the frame stations along the centerline and draw a line to indicate each one, at exact right angles to center and base lines. Draw the plan of the boat just as it will actually be, taking halfwidth and height measure­ments from the offset table, spotting them on your drawing and connecting them up with pencil lines. It is only necessary to draw half the boat in plan view.

Having completed the full-size drawings, you are ready to cut the frames, gussets, keel, keelson, stem, transom and knees. You will note that the offsets are given to the inside of the planking, so there is no need to make allowance for the thickness of the latter, all frames being matched up right to the line on the body plan. Spread the body plan on the floor, with the base line at the top, take measurements of frame sides and bottoms, as well as the angles at keel and chine, and saw out the 24 frame pieces (4 pieces to each of the 6 frames). Be sure to extend the side pieces clear up to the base line. This causes the frames to automatically assume the correct shape of the bottom when they are placed upside down on the building frame. After the hull has been planked and turned over, these extra lengths will be trimmed off at the sheer. As you finish cutting each frame, place it on top of the body plan at its station for a final checkup. Don't forget to mark the station number on each piece of frame to avoid a mixup when assembling.

Next step is to cut the gussets (the angu­lar pieces that tie the frames together) from ⅜-in. fir plywood. The simplest and most accurate procedure is to lay a large sheet of tracing paper over the body plan and trace off the angle at the chine and sheer of each frame. Mark the outside line of each gusset 8 in. along the side and bot­tom of each frame, then at right angles across the thickness of the frame. A diag­onal line from the two points thus estab­lished completes the shape of each gusset. Use the same procedure for the floor beams, allowing these to extend 14 in. or more along the frame bottoms. The out­lines may now bs transferred by means of carbon paper directly to the fir plywood.

Place the frame pieces, starting with No. 1, on the floor in their assembled posi­tion and coat with red lead the joints and places where gussets and floor beams will cover. While the paint is wet, clamp the gussets and floor beams to the frames, fast­ening in place with 1½-in. No. 10 flathead brass screws. When all have been com­pleted, crossties of scrap lumber are fast­ened flush across the open ends or tops of the frames. The six assembled frames may be laid aside until needed.

The three parts of the stem are cut from one piece of mahogany, 6x3 in. x 6 ft. long. Mark the three sections accurately on the wood from the full-sized drawing pre­viously made. After they have been cut out mark the taper at the front edge, using the cross-section drawing as a guide. Clamp each piece to the workbench and trim with a drawknife, smoothing off with a jack plane. The piece at the bottom has very little taper, being practically flat where it runs into the keel. Place the stem pieces on the floor and fit them to­gether. The lock scarphs should fit snugly, and the whole go together like pieces in a jigsaw puzzle. Take the stem apart, paint the joints with red lead, reassemble and bolt together with bronze or galvanized carriage bolts of the sizes indicated in the bill of materials. Countersink the heads in the outside of the stem. If the boat is to be used in salt water it is best to em­ploy bronze and brass fastenings through­out, as these will materially add to the life and value of the boat and be well worth their extra cost. The stem may now be roughly rabbeted with mallet and chisel, or you may wait and cut the rabbet after the framework has been set up. Note that the stem must be rabbeted to take the ⅜-in. side and bottom planking. The stem must also be notched for chines and sheer strips, but this, too, is best done later on.

The transom, transom frame and knee come next. Mahogany planks, 8 in. x ¾ in. thick, are glued up and used for the tran­som itself. Cut to the shape and dimensions indicated. Assemble ¾x3-in. mahogany transom frame on the transom, fastening with 1½-in. No. 10 flathead brass screws. Allow about a half inch of transom frame to project out over the sides and bottom of the transom; this takes care of the bevel for the planking later on. Mark the outlines of the transom knee accurately on a piece of 2x7¾-in. x 3-ft. mahogany and band-saw to shape. Fasten the knee to the exact center of the transom 5/16 in. above the bot­tom edge with A-in. carriage bolts run through from the outside with heads coun­tersunk. The ⅝-in. clearance allows a notch to be cut in the transom frame to receive the end of the keel.

The 16-ft. lengths of oak and Alaskan cedar which become keel and keelson must be tapered from station 2 forward and from station 5 aft. Next cut out the centerboard slots, using care to get them both alike. You will have found that the 16-ft. planks are a bit too long—they should be trimmed to exact length at the forward ends and allowed to lap over aft.

Now, set up the building frame. Obtain two cheap but straight 2x6's, 18 ft. long. Place them parallel on edge about 30 in. apart. Take care to have them exactly level. Nail scrap lumber across the ends with heavy galvanized nails, and fasten three or four cross braces in between to give a very rigid assembly. Give the frame a final check for level and run a strong cord along the exact center from end to end, pulling it taut and tacking securely.

Bring out the six completed frames and mark a center line on each crosstie. Cut a notch the width of the keelson and ⅝ in. deep in the bottom of every frame. Bevel these notches so the keelson will fit per­fectly flat in each one despite this curve; the bevels can be taken from the profile drawing or determined by setting the frames up temporarily and running a bat­ten across the bottoms. In any case, cut the notches carefully and set the frames on top of the building frame,  after first marking station lines on the latter. Frames 1, 2 and 3 must be placed just forward of the station lines, and 4, 5 and 6 just aft of their station lines. In other words, the aft edges of the mahogany parts (not the crossties) of frames 1, 2 and 3 should be the station lines, and the forward edges of 4, 5 and 6 must do likewise. Drop a plumb line from each frame before finally bracing it in position. After all frames have been securely braced in their correct positions and crossties nailed to building frame you are ready to bend in the keelson and keel.

First lay the keelson in its notches and bend it down to frames 1 and 6, clamping it at those points. Place the keel on top of the keelson, bend it down and clamp. Two 5/16-in. carriage bolts are run through keel, keelson and frame, with heads coun­tersunk in the keel at each frame except frame 1, where only one bolt is used. A filler block is placed in the V at this frame, through which the bolt is fastened.

The transom with its attached knee is next set up in position on the building frame. The keel and keelson may now be trimmed until, when pulled down flush with the knee, they are just even with the outside of the transom. Notch the transom frame ⅝-in. deep for the keelson, and rasp the end of the latter until it seats nicely in the notch. Fasten with carriage bolts in the same manner as the frames. The stem can now be bolted temporarily in position with two long carriage bolts.

The framework has now become a rather rigid unit, but nothing compared to what it will be after chines and sheer battens have been put in. The former consist of two pieces of yellow cedar ⅞x2¾ in. x 18 ft. long. The sheer strips are somewhat smaller, being ⅞xl¾ in. x 19 ft. long. Notches must be cut in the frames to ac­commodate these pieces. First cut the chine notches, allowing the chine to fit even with  the side  angle  of  the  frames  and project slightly beyond the bottom, to be beveled flush after fastening. The fore and aft bevel can be obtained by bending a long, light batten around the sides of the frames and marking the angle on each. After the notches, including one in the transom frame, have been cut, bend in the chines and fasten with two 2-in. No. 10 flat-head brass screws into each frame. Mark off the sheer line on the frames, cut notches and bend in the sheer battens.

Before   starting   the   final   assembly   of   frames, check   for   accuracy   on   the   full-size   body   plan. Complete each frame by laying gussets and floor beams in wet red lead; secure with brass screws Scrap-lumber   crossties   are   nailed   flush   across the tops or open ends of the completed frames. Filler block, glued in Frame  1, anchors carriage bolt   running   through   keel,   keelson   and  frame.

The next task is to bevel all the frames, sides and bottom, until a continuous smooth surface with no corners or edges is attained, on which the planking will fit like a glove. The transom, of course, must also be beveled, as well as the keelson.

Now unbolt the stem and roughly chisel out the rabbet, following the cross section drawing. Cut the notches for the chines and sheer strips deep enough so that the ends of these pieces will fit flush into them, the outsides level with the planking rab­bet. Replace the stem, tightening the bolts and fastening the ends of chine and sheer pieces in their notches with 2-in. No. 10 screws. Check the rough rabbet with a strip of wood several inches wide and 5 or 6 ft. long. Lay the wood along the frames near the bow, clamp it and bend the end down into the rabbet. Do this at intervals, trimming the rabbet as you go, until the plank fits neatly into the rabbet everywhere.

In planking Bonnie II, the sides are covered first, two pieces to each. Get out your roll of building paper and make two patterns for the side; a full 12-ft. one and another to cover the rest of the length. On one side use the short piece at the bow, on the other side at the stern, thus stag­gering the joints. Allow the pattern to come about ¼ in. above the chine and be­low the sheer.   Place the patterns on the ⅜-in. plywood sheets and pencil around them. Cut out the panels and clamp them in place on the sides. Drill holes for l¼-in. No. 8 flathead brass screws; 5 in. on centers along frames and sheer; 3 in. on centers at chine and stem. Take marine glue and swab it plentifully along the chine, stem and transom. Coat also the corresponding edges of the panels, on the underside only. Now take strips of cotton flannel (torn into 3-in. wide strips) and lay them along the gluey chine, stem and transom. Replace the panels with clamps, and turn in the screws until they are just below the surface of the plywood. When all pieces are on tight plane the edge that projects below the chine until it is beveled even with the lat­ter. Follow the same procedure to plank the bottom, placing flannel and glue along keel, chine, stem and transom. It will be neces­sary, however, in the case of the bottom to put short panels at the bow, as a 12-ft. length is too hard to manipulate into the stem. Put in the bow panels first, clamping the aft ends to keelson and chine, then working the forward ends gradually down to the stem. When the panel has been forced to the stem put in several screws quickly to hold it. The two long bottom panels will go on as easily as the side pieces. Space the screws at 2 in. on centers along the keel and stem, 3 in. along the chine and transom, 4 in. on the frames.

Bevel the edges of the bottom planking until they are flush with the sides and transom. Butt blocks may be put in at this time. Set the butt blocks in flannel and marine glue, fastening with double rows of screws spaced at 3-in. intervals.

Next, cover all screw heads with Kuhl's trowel cement and fill the seams along keel, stem and butt joints with elastic seam compound. Sand the bottom smooth and apply two coats of copper bottom paint, red, green or bronze, coming just up to the waterline. The boat is ready to be righted and will need a cradle to rest on.

1st: with  the  frames  beveled  and  chines  flush with  bottom,   only   the   keelson   needs   beveling.

To install the centerboard trunk, cut off the frames and crosspieces extending above the sheer at stations 3 and 4. Then cut away the frames and floor beams on each side of the centerboard slot to accom­modate the completed trunk. Next the trunk is completed as shown in the draw­ing. Be careful in shaping the bottom as it must fit flush on the keelson to be water­tight. Paint the inside of the trunk with four coats of bottom paint before it is as­sembled. Use l½-in. No. 10 screws to fasten the bed logs to the sides, driving them from plywood through mahogany. Then locate and bore holes through keel, keelson, and bed logs for the hold-down carriage bolts. Cut a gasket to fit over the slot and set it in a liberal quantity of marine glue. Put the trunk sides in po­sition and ram down the end pieces. The forward post must stick up well above the top of the trunk so it can be tied into the cabin roof. Fasten the end pieces in place from both sides of the trunk, using 1¼-in. No. 10 screws. Run the bed log bolts up through from the outside and tighten with nuts and washers from the inside until the glue oozes out. Install the centerboard.

Cut off the remaining projecting frames at the sheer and plane down any edges until flush with the sheer. The ⅜-in. ply­wood deck beam gussets are now cut. At frames 1, 2, 5, and 6 they can be tri­angular in shape, extending about 8 inches down the frame sides and 8 inches along the deck beams. Frames 3 and 4 show in­side the cabin so you'll want to cut their edges with a graceful curve. Clamp the gussets to the frame tops and fasten with 11/2-in. No. 10 screws. The three full-length deck beams and the short side ones are all cut from a 12-ft. plank as shown. The beams are clamped one by one to the gus­sets, with their outer end butting against the frames, then screwed into place.

Next, bend in the two longitudinals that form the main fore and aft supporting members of the deck and cabin. Notch them into the deck beams and transom frame, and fastened at each deck beam with one screw. Two other longitudi­nals are run under the fore deck on each side of what will be the hatch. These are notched into the breast hook and frames 1 and 2. The short side beams are notched into the main longitudinal and fastened with one screw at each joint.

The mast pardner, not shown, fits just aft of frame No. 2. It is a 3x3x8-in. block of mahogany. An opening, 31/2x41/2 inches, is cut out of the center to take
the mast, allowing ample room for wedging when the mast is stepped. A small hatch opening is provided just forward of frame No. 1. Three sides are formed; fasten a cross-piece to provide the fourth. Place an up­right brace under the deck beam at frame No. 6, securing with screws to the floor beam.

The covering is comprised of six sec­tions: two forward, one on each side and two aft. Three panels of ⅜-in. plywood are used. Make paper patterns of the deck section before cutting the plywood. The plywood is fastened with 1-in. No. 8 flat-head brass screws spaced about six inches apart. Butt blocks are placed under the side deck joints and ¾-in. plywood filler pieces back up the joint in the fore deck. The same arrangement is used at the joint in the after deck.   Run seam compound in to the seams. Stain the deck and apply one coat of varnish right away.

Construction of the cabin has been kept simple. The principal side supports are eight pieces of 1⅛x2¼-in. fir, four to a side. The back ones, at frame No. 4, are carried down to the floor frame and fastened to it with screws. The other uprights do not ex­tend below the deck framing and are screwed to the longitudinals. Bevel the lower ends of these uprights so that they will stand straight, as the longitudinals have an outward slant. The three aft up­rights on each side are placed with the greater dimension running lengthwise; the forward ones are set in the opposite direc­tion and notched to receive the roof stringers.

The front panel of the cabin goes on next. Use 1¼-in. No. 8 screws to fasten it to the uprights. Bend in the roof stringers se­curing them to each upright with two 1¼-in. No. 8 screws. Cut the two back pieces and stand them in place. Make paper patterns of these, taking measure­ments from the inside of the boat. Notch the chines and sheer strips, and fasten them to the back uprights with 1¼-in. No. 8 screws.

Cut two more pieces of fir for door frames and screw them to the edges of the door opening. Run screws from plywood into fir. It will be found that these up­rights, running down behind the slide rails for the removable panels, can be fastened to the floor beam for extra strength. Cut two fir end carlins and screw them to the plywood end pieces, allowing the outside ends to rest on the uprights. The inside ends butt against the door frames. Now saw out the carlin which fits against the front panel and fasten it in place with 1¼-in. No. 8 screws. The two fore and aft roof beams of ⅞x2-in. oak come next and are notched and screwed to the end carlins.

The cabin sides are ⅜-in. plywood and continue aft to a point six inches beyond the cockpit, acting as splashboards. The bottom edges are snug against the deck all along and must be trimmed in a slight up­ward curve to attain this. Screw the sides to the framework and clamp around the edges of the cockpit temporarily.

The splashboards are lined with ⅜-in. plywood of the same shape but extending down inside the cockpit to cover the deck framing. At the aft end of the cockpit the pieces are notched so the extremities will rest on the afterdeck alongside the splash­board, giving a ¾-in. thickness to the splashboard. Remove the temporary clamps on the splashboard and screw it and the lining to the deck longitudinals. Side ports are cut now or later. The re­maining roof carlins are notched into the tops of the fore and aft roof beams and fastened with one screw at each joint. The roof is covered with plywood in three sections, with joints meeting over the roof beams.

The removable panels and slide rails can be fitted below the cabin doors. The top panel is rabbeted as shown to form a stop for the doors. Fasten the hatch slide rails to the cabin roof with 2-in. No. 10 screws, driven from the inside up through the roof panels.   The hatch cover is made as shown.

Construct the forward hatch cover also, following the sketch. Stain and varnish all exposed mahogany surfaces. Paint the outsides of the hull, cabin sides, front and ends with two coats of yacht white, flat. The inside of the boat should be given a priming coat of aluminum paint, followed by a coat of semi-gloss interior paint.

  Put on the deck hardware, door-hinges, rudder gudgeons, etc. The bow and stern chocks, bow plate, lip leaders and hinges are screw fastened; mooring bitt, gudgeons and cleats are through-bolted.

For auxiliary power the boat has a 2½-hp, air-cooled, 4-cycle, single-cylinder engine. This engine will move the boat along smoothly at about five knots. A 2:1 reduction gear cuts the boat's speed to less than one knot for trolling, yet allows the engine to operate efficiently within the recommended rpm. The reduction gear is fabricated-from stock bearings and pulleys and mounted on a non-corrosive frame with the engine. A simple, two-position clutch connects the engine to the shaft. In­cidentally, the 9x6-in. propeller, bronze shaft and stuffing box were bought in a surplus marine center for less than $10.

Construction of the engine mount is de­tailed in two drawings. The engine stringers are notched into the floor beams and frames and leveled off. As the bottom slopes upward toward the stern, the notches at frame No. 5 will have to be somewhat deeper than those at No. 4. When it is done, the stringers are lag-screwed to the frames. The exact angle of the tri­angular pieces on which the engine rests must be determined on the job. Tem­porarily bolt the pieces in place on the stringers and place the engine upon them.

Determine the spot where the shaft will go through the bottom of the boat and cut a 1-in. wide slot through the keel and keel­son at this point. Make the skeg as shown, assemble with screws and marine glue and shape the top to fit flush against the keel. Be sure the slot in the skeg is roomy so that the shaft will not bind.
Place the skeg up against the keel and wedge it in place with a stick between it and the floor. Then get down on hands and knees and peep through the shaft hole to see if it lines up with the engine coupling. If the shaft opening is in correct alignment, the coupling will appear as a perfect circle in the exact center with none of its inside walls visible. When you think you have it, run the shaft itself into the opening and push it into the coupling. It should go in quite easily if the lineup is correct.   Check that it revolves freely without binding and, when satisfied, bore holes through the keel from the inside for the lags and bolt that will hold the skeg. Remove the skeg and cut a canvas gasket to fit be­tween it and the keel, allowing a hole for the shaft. Soak the gasket in marine glue, put it in place and fasten the skeg. Replace the shaft and secure the engine permanently.

The rudder is cut from ¾-inch fir ply­wood to the shape and dimensions given in the drawing. The tiller may be either ma­hogany or oak. It is held to the rudder by side pieces of oak. A carriage bolt pivots the tiller assembly on the rudder.

The inside of the cabin and cockpit will not be described in detail, as each builder will have his own ideas about how he wants them arranged. However, a few general suggestions may be of help. You will probably want two bunks. Let them run from the aft cabin walls forward and diagonally in toward the center of the boat until they almost meet in front of the mast step which should be put in before the bunks and fastened to the keel with two carriage bolts inserted from the outside.

It is suggested that two seats be installed lengthwise on either side of the cockpit, at a convenient height. Plywood, ½or ¾ in. thick, is ideal for flooring, both in cabin and cockpit. Cabin floors are supported by the floor beams. In the cockpit it will be necessary to screw extra supports to the beams and cut the floor boards to fit around the motor. Incidentally, if you de­cide to pipe the exhaust out through the transom, a hole should be cut in one of the floor boards to allow the pipe clearance.

Use 1-inch quarter-round moldings along the deck cabin seam, and 1-inch half-round along the deck-topsides seam and cabin roof seam. Set all molding in Kuhls bedding compound and fasten with countersunk, plugged screws.

Spar construction is detailed in the drawings. Note the use of filler blocks in the hollow mast wherever hardware is used. Mast and boom are finished with four coats of top-grade spar varnish, sanding lightly between coats. A paint job com­pletes the boat.

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