Build the speedy "Stiletto"By ARTHUR MIKESELL

With sleek SK streamlining and a super-speed

bottom, it's 16 feet of high-performance boat

HERE'S ONE OF THE BEST high-speed run-abouts you'll ever see presented as a boat-build-ing project.

It's designed strictly for speed, with a mini-mum of compromise. That broad flat bottom isbuilt for quick getaway and maximum go, a com-bination which makes this a top ski boat. On theother hand, if you want to fish, run a rough chopor carry more than four people, better shoparound for something a little more tame. Stilettois a frisky thoroughbred, not a workhorse.

Construction follows stock boat-building rules.All lumber over 1 in. should be "four quarters"stock finished as full as possible, which usually

means from 3/4 in. to 7/8 in. All lumber thicknessesunder 1 in. should be considered net.

Use oak, mahogany or spruce if available.Otherwise, substitute any species commonly usedin boat construction in your area. All plywoodmust be at least exterior grade, and preferablymarine grade.

All joints should be glued with a hard-settingglue of the resorcinol or plastic-resin type. Fast-enings should be hot-dipped galvanized or bronze.

All frames are fabricated from 1-in. materialfrom dimensions given in the drawings. Thetransom is made from 3/4-in. plywood with amotor board of the same material in the center

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portion. A framework of 1-in. lumber is used atthe contact areas of side deck and planking.

The laminated stem is laid out from givendimensions, using a batten sprung between theindicated points to draw the contour. The breast-hook fits on top of the stem and acts as a block-ing to connect the sheer clamp to the stem.

The building form should be set on a fairlylevel and smooth surface. Anchor the base mem-

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Bevel notches for both sheer clamp and chinelog so that they will fit flat when you bendthem over the framing

Fair chine along the line from Frame No. 5to the center of the chine at the stem sothe bow portion of planking will fit

The planking pattern cut slightly oversizefrom wrapping paper helps when laying outthe sides on the plywood stock

When planning to fit butt joints in the for-ward bottom planking, wet the plywood toprevent it from splintering

Motor-well knee fastens to the carling, tran-som blocking and, for large outboard motors,blocking on the batten

Motor-well bottom fastens to the bottom edgeof the well beam and to the side blocking,shown above being fitted in

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ber firmly so it will not move. Each frame ismounted bottom-side-up on the form, centeredand spaced according to the dimensions noted inthe drawings. The position of the transom is ob-tained by installing the keel.

Align the stem with a chalkline exactly on thecenter line and block it to the height indicated.The full-length 1 x 4-in. keel is laminated onthe inside with strips of 1/4-in. plywood to preventsplitting. These should be glued and fastened tothe keel with nails. The position of the chine onthe stem is found by bending the member aroundthe hull and allowing it to take a natural curve tojoin the stem. After cutting the bevel, fasten thechine at the stem first and spring it around thenotches, leaving it long at the transom so youcan cut it to exact length after it's fastened inplace.

The sheer clamps are built up from two lam-inations of 5/8 x 1-1/4-in. lumber set in verticallyfrom midships forward. Aft, they may take atwist for sufficient surface to fasten decking andside planking.

Bevel the notches as you did for the chinemember and fasten the first lamination to thestem and breasthook, then spring it around thehull, fitting it into each notch. Coat the initial

lamination with glue and apply the second, usingplenty of clamps or nails to hold the laminationsuntil the glue sets. From Frame No. 5 forwardto the breasthook, a third lamination of the samesize material is laminated on the inside of thesheer.

The 1 x 3-in. battens should be spaced ap-proximately as shown on the drawing, thoughyou may vary the spacings slightly to allow thebattens to take a natural curve. The battensshould flow in parallel lines from No. 2 aft,viewed in profile.

All frame members must be beveled, or"faired," to allow the plywood planking to fit flatagainst the frame. Approximately from FrameNo. 5 aft, the bottom planking will lap the sideplanking. Forward of this point a transition ismade where the bottom planking ceases to lapthe side planking, and from this point forwardthe side and bottom planking meet on the chinein a butt joint.

Use a short length of plywood to check thefairing, working from the transom forward. Thesheer clamp, particularly the forward sectionclose to the breasthook, will resemble a triangle.

The side planking is preferably full-length1/4-in. marine AA-grade plywood. If shorter panels

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are used, locate the butt joints between frames.The contour of the planking is obtained by

laying the panel against the hull side and tem-porarily holding it in place with screws or clampswhile the shape is roughly marked around thecontour. Remove the planking and cut to shapewith a fine-tooth hand or power saw. The onlyplace close fitting is required is from the transi-tion point forward. All other edges may be leftlong for trimming after the planking is fastenedpermanently in place.

The bottom planking is 3/8-in. plywood; pref-erably full-length, though shorter, butt-joinedpanels may be used by fitting butt blocks betweenthe bottom battens.

Fit the bottom as you did the side planking.Roughly mark the stem area and cut away asmuch material as possible to make the bendeasier. To fit the butt joint at the side planking,start at the transition point and fit progressivelyforward to the stem. After coating the initialpanel with glue and fastening it in place, trimthe planking flush with the stem from 12 in.forward of Frame No. 5.

The second half of the bottom planking willbutt-join the first panel along the keel aft of thispoint. Forward of this point the second panelwill lap the first. After planking the bottom, thehull should be righted and blocked level.

The carlings are 1-in. longitudinal membersthat form the side extremities of the cockpit.Crown each one to follow the contour of the sideframe members.

The coaming fits inside the carling and isnotched up between Frame No. 1 and the tran-som so the side of the motor well can be fastenedto the lower 1-1/2 in. of the carling. This memberalso forms the cowl, which is the raised portionof the forward deck. The decking in this arearabbets into the coaming.

dash beam after deckingThe beam at Frame No. 6 is fastened to block-

ing on the inside of the sheer clamps. The dashbeam at No. 4 and the intermediate beam be-tween Nos. 4 and 5 have the same contour asthe No. 5 deck beam. These beams are fastenedto blocking on the coaming. The dash beam isfastened in place after the decking is installed.

The sawn batten extends from the No. 5 deckbeam to the breasthook. The batten is used as abacking member for the junction of the side andforward decking. (Optionally, this batten maybe made from two laminations of 3/4 x 3/4-in. ma-terial sprung into position around the hull.)

The deck battens and the strongback arenotched into each of the beams. The battens endup against the sawn batten, while the strongbackrests on top of the breasthook. Add pine blockingon the breasthook to provide a solid bearing fromstrongback to sheer.

Deck framing must be faired as you did thebottom and sides. It will be necessary to fair thebatten for the side decking, but little if any fairingshould be required for the forward side decking.

The fore decking is put on in two parts andbutt-joined over the strongback. Fastenings arerequired only around the outer extremities of thepanels.

The transom is gusseted to the carling with3/4-in. plywood knees fastened to the carling andblocking on the transom. A 2 x 4-in. braceextends between these members across the tran-som and is fastened to the gusseted knee as wellas the center knee and transom.

modifications for big motorsFor motors in excess of 65 hp, extend the

3/4-in. knees from the carling all the way downto the bottom battens. Fasten 1-in. blocking ontop of these battens and use screws to secure theknees.

The control console between the seats must betailored to hold the gas tank which you plan touse. The built-in tank measures 6 x 12 x 24 in.and is made of 20-ga. terneplate.

Seat treatment is a matter of choice. In theprototype a semibucket seat was made by ex-tending uprights at the side portion of the seats.Upholstery was installed by an auto customizingshop.

A cast-aluminum skid fin approximately 5 in.deep is located with the front edge at FrameNo. 3. Fasten in place with eight 1-1/4-in. No. 8screws.

All screw holes and minor imperfectionsshould be filled with a hard-setting putty. Fiber-glass covering is optional, and if used, should bea single layer of 6 or 8-oz. cloth double-lappedat the seams. All plywood surfaces not fiber-glassed should be coated with a plywood sealerand given adequate primer, sanded betweencoats, to hide the grain. Finish with a minimumof two coats of a good marine enamel. All sur-faces to be given a natural finish should bestained (and filled, if required) to the desiredcolor and given a minimum of three and prefer-ably five coats of marine varnish.

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