Build The Tango: by Hank Bravo [PDF]

Zitiervorschau

Build the Tango 

by Hank Bravo

About Tango 17 Tango 17 was designed to be an easy to be build (no frames, no ribs, no lofting), lightweight, low-power planing skiff. It can carry up to four passengers and is powered by an outboard motor in the 20 to 30hp range. Tango’s unique transom design improves balance, weight distribution and performance. Tango 17 is built using the “stitch & glue” method, which, for the most part, requires simple tools and basic woodworking skills. This method produces a strong, lightweight hull. Since all joints and seams are filled and reinforced, a precise fit is not required.

Dimensions The designer has made every effort to insure the accuracy of these drawings. However, due to the nature of drawing and cutting curves, adjustments will be necessary. It is important to check dimensions of seats and bulkheads against the assembled hull before final cuts are made.

Safety As a small boat, Tango 17 should only be used in protected waters and in favorable weather conditions. Do not overload or over-power her.

Customizing Part of the fun of building your own boat is customizing it to suit your needs. However, there are some things to consider when making changes. First, this boat was designed to have three water-tight compartments, one in the bow and two in the stern, to provide flotation in case of swamping. When modifying the interior, be sure to maintain adequate flotation. Secondly, the seats, bulkheads and floorboard provide the structure that stiffens the hull. When making changes to the interior, be sure to maintain adequate support for the bottom and sides.

Disclaimer The designer makes no claims or warranty of suitability or fitness for a particular purpose. Proper construction and use is the responsibility of the owner/builder.

Tools

Materials

Jigsaw with fine tooth blade

10 sheets – 1/2” (12mm) marine plywood

Circular saw with fine tooth blade

Approximately 5 gallons epoxy resin plus hardener (estimate)

Table saw (optional)

2 quarts Wood Flour for making fillets

Router with 3/8” roundover bit

2 quarts Silica Thickener for making fillets

Random orbit sander

3 quarts Phenollic Micro-Baloons for hull fairing

Detail sander

25 yards of 50” wide, 6oz. Fiberglass cloth to reinforce hull

Low-angle block plane

25 yards of 2” wide fiberglass tape to reinforce seams around seats

Wood chisel

25 yards of 3” wide fiberglass tape to reinforce seams around bottom & bulkheads

Clamps

10 yards of 8” wide fiberglass tape to reinforce centerline under floorboard

Straightedge

12” plastic cable ties for stitching hull together

Measuring tape

access hatches – builder’s choice

Scissors

One-part polyurethane marine enamel for hull interior & exterior

Supplies

One-part polyurethane marine varnish or Spar Urethane for seats

Disposable gloves and shop towels

polyurethane marine adhesive/sealant for installing hatches and thru-hull

Disposable brushes & measuring cups

Cleats, bow-eye and other hardware as needed

Foam rollers

Bronze or plastic thru-hull with drain plug

Model A model can help you visualize how this boat is built. To assemble the model, print the following two sheets on cardstock, cut out the parts, and assemble with tape and quick dry glue.

Plans Tango 17 is built entirely from parts cut from marine plywood. The following pages show dimensioned drawings of each part.







Plywood Sheet Layouts The following pages show how each part is laid out on a sheet of plywood. The drawings show a 1” x 1” grid to help determine dimensions and lay out curves.













Stands To insure the hull is shaped properly, I’d suggest building stands as shown on the following drawing. The top of the stands are shaped to match the transom and forward bulkhead.

Construction At this time, the Tango 17 has not been built so I don’t have actual photos of its construction. However, I’ve done my best to find pictures of other boats to illustrate each step of the process. The boats in these pictures may look very different but the process is generally the same. Here are the steps: Rough cut the plywood sheets Scarf the side and bottom panels Trim side and bottom panels to final dimensions Laminate panels to make transom Trim transom to final shape Drill holes in bottom and side panels for stitches Stitch bottom panels together Stitch side panels to bottom panels Install transom after fitting and trimming Spread the hull sides to beam width Cut and fit bulkheads and seats Cut and fit rear panels     

       

1 Scarfing the Side & Bottom Panels A scarf joint is one of the strongest ways to join two pieces of plywood. C tting scarf joints can seem intimidating but it’s really not hard. The first step is to lay out the panels to be joined. The scarfs need to be cut on opposite sides, the top side of one panel and on the bottom side of the other panel. So, lay out the panels you want to join then flip one over. Draw a line 2-3” from the edge of each panel. You want to make an angled c t from the edge of the panel to this line. You can set up a fence on a circular saw to make the angled c t or you can just use a block plane, holding it at a slight angle. After the scarfs are cut, it’s time to glue the panels. Lay both sections down on wax paper, scarf side up. Mix a small amount of epoxy and spread it onto both sides of the scarf joint. To prevent a starved joint, it’s good to let the epoxy soak in for a few minutes then re-apply. Next, flip one section and join to the other, making sure to carefully line up the panels. After aligning, clamp the panels down to prevent any movement. Finally, cover the joint with wax paper, weigh it down and let the epoxy cure overnight. After scarfing, the bottom and side panels can be cut to their final shapes and prepared for stitching. The transom is also laminated and cut to shape.







Marking a 3” strip for the scarf joint.

 Cut the scarf joint using a block plane.

 Do the same to the other bottom pieces.



Bottom panels ready to be glued.

 To start, lay the pieces over wax paper.

  Joints are glued with epoxy thickened with silica.

Some of the tools used to build the Tango Skiff. With a stack of plywood, It’s time to get started. First, rough cut the panels that make the bottom.

Epoxy spread heavily on both sides of joint.

  Joints covered with wax paper and weighed down. The next day, panels are ready for shaping.



Stack the bottom panels and draw shape.

 Use a flexible piece of trim to draw the curve.

 Cutting tab at the rear of bottom panel.



Curves cut with jigsaw.

 Drilling holes every 8 inches for stitching.

 Bottom panels complete.



 Rough cut the pieces that make the side panels. Mark a 2” strip for the scarf joint.

 Scarf joints cut. Panels ready to be glued. 



Applying epoxy to both sides of scarf joint.

  Joints covered with wax paper and weighed down. Side panels stacked and cut to final shape.



Cleaning up jigsaw cuts with block plane.

 Side and bottom panels complete.



 Next, marking matching holes on side panels.

   Drill holes in side panels at the bow for stitching. Knock the inside edge off the sides at the bow. Knock the inside edge off the bottoms at the bow.

Rough cut the transom panels.

Cover with wax paper and weigh down.





Soak both pieces with epoxy for laminating.

The next day, cut transom down to final shape.



 Lay the panels over wax paper on a flat surface.





Finally, rough cut the bulkheads.

      

2 Stitching the Hull After the bottom panels, side panels and transom are ready, it’s time to stitch the hull together. Start by stitching the bottom panels together loosely using plastic cable ties and lay them out on the stands. Add weight at the stern to help flatten them out. It will take time to bend the bottom panels into shape so do this over the course of several days. Be patient and give the plywood time to get used to its new shape. While the bottom panels are adjusting, you can start stiching on the side panels. Start from the back of the boat and work forward, supporting the side panels alongside the bottom panels. Once the side and bottom panels are stitched together, you can start fitting the transom, bulkheads and seats.



Hull parts ready for stitching.

Support side panels alongside bottom panels.







Start by loosely stitching bottom panels.



Lay panels open on stands and weigh down.

 Stitch the sides to bottom starting at the stern. Slowly pull the sides in at the bow.

Give the plywood time to adjust to its new shape. A few extra stitches help pull the bow together.









 After a day or two, the bow should come together.

3 Fitting the transom, bulkheads, floorboard, seats and anchor locker Once the side and bottom panels are stitched together, you can start fitting the transom, bulkheads, floorboard and seats. Locate the transom, trim if necessary and secure temporarily with screws or cable ties. Once the transom is in place, spread the hull sides to beam width minus 1”. Make sure the sides are level just forward of the transom. Adjust the height of the stands if necessary. Now you can begin fitting the bulkheads, floorboard and seats. Note that the floorboards main purpose is to stiffen the bottom panels. Therefore, it only extends to roughly the middle of each bottom panel. If you choose to widen the floorboard you will need to provide additional structure to stiffen the bottom.



Test fit transom.



If needed, trim transom with block plane.



Secure sides to transom.

  Spread hull at midship (max beam - 1” ) and bow. Check that top of side panels are level at stern. Begin fitting bulkheads.

Check that bulkheads are level.



Cut and fit rear seat panel.







 Check that seat is level. Adjust bulkheads if not.

Test fit the forward bulkhead.

Cut the pass-thru in floorboard.

Check that both seats are aligned and level.







Trim as needed with block plane.

Floorboard complete.

Finally, rough c t the anchor locker.







C t and fit the floorboard.

C t and fit bow seat. Check for level.

Anchor locker cut and fit.







4 Fitting the rear panels, rub rails and cap rails After the seats and bulkheads are installed, it’s time to install the rear panels. It’s a good idea to cut these slightly oversized and then trim to fit. Once the rear panels are installed you can add the rub rails. The rub rails can be temporarily attached with small screws. Next you can start working on the breasthook and cap rails. The cap rail should overlap the edge of the side panels and the rub rail.

Rear panels rough c t.

Fitting rub rails.

Fitting the cap rails.

Test fitting rear panels.





Attach temporarily with small screws.

Marking cap rail curve.

Rear panels c t and trimmed to fit.





C t and fit breasthook.

Breast hook and cap rails complete.





5 Adding a console On the Tango 17, the gas tank would fit under the rear seat and the console could house the battery. As drawn, the dimensions of the console should allow for comfortable steering when sitting and standing, but you may want to make adjustments for your own comfort.

C tting and fitting the console.

C tting and fitting the console.

Gluing console panels.



Gluing console panels.

All parts cut and fit. Ready for epoxy. 

Console cut and assembled.



Console cut and assembled.



6 Epoxy & Fiberglass

The goal of “stitch & Glue” construction is to create a strong, lightweight, one-piece structure. Tango’s seats and bulkheads brace and stiffen the hull. Therefore it’s important that all seams and joints are filled thickened epoxy and reinforced with fiberglass tape. The exterior of the hull gets sheathed in fiberglass cloth for strength and abrasion resistance. Finally, all surfaces are saturated with epoxy to prevent water penetration. To begin, I spot glue the stitched hull with epoxy. Once dry I remove the stitches. Next I spread epoxy along the edges of the transom and set it in place. I secure the side panels to the transom temporarily with small screws. After spreading the hull I glue the bulkheads in place. Once the transom and bulkheads are in I can fill all the seams with thickened epoxy fillets and reinforce them with fiberglass tape. I make fillets using epoxy thickened to the consistency of peanut butter with one part silica and two parts wood flour. To get a nice radius on the fillets I spread them using a wooden mixing stick that looks like a tongue depressor. I reinforce the seams along the hull, transom and bulkheads with 3” wide fiberglass tape. Before setting the floorboard I need to reinforce the keel. I use several layers of increasingly wider tape to build up the thickness of the keel. Next I wet out the underside of the floorboard with epoxy and set it in place. Once set I need to fill and level along the edges with thickened epoxy. Finally, I think it’s a good idea to cover to entire cockpit floor with fiberglass cloth. This area between the bulkheads will take most of the pounding when the boat is on plane so it needs to be adequately reinforced. With the floorboard in place, it’s time to glue in the seats. I wet out the underside and edges of the seat and set them in place. When the epoxy begins to set, I fill the seams with fillets and reinforce them with 2” wide fiberglass tape. Next I can glue on the rub rails. I’ll wait until later to add the anchor locker, breasthook and cap rails. The final step before flipping the hull is to cover the transom and rear sponsons with fiberglass cloth.

Some of the tools and supplies used to epoxy.

Glueing the transom in place.

Glueing the bulkheads in place.







Start by glueing between the stitches.

Attaching the side panel to the transom.

Filling the seams around the bulkhead.









When the epoxy sets you can remove the stitches.



Spreading the hull sides.

Making fillets with thickened epoxy.





Taping the seams with 3” fiberglass tape.

After keel is taped, floorboard can be added.

Installing seat (floorboard not shown).







Filling and taping the seams around the transom.

Underside of floorboard wet out and glued down.

Seams filled and taped.







Fiberglass tape wet out with epoxy.



Edges faired and covered with fiberglass cloth.

Wetting out tape and seat.







Wetting out underside of bow seat.

Installing rear panels and wetting out interior.

Transom and sponsons covered in cloth.







Seat glued in place.

Rear panels installed.

Fiberglass cloth wet out.









Seams filled and taped with 2” fiberglass tape. 

Seams filled and sanded smooth.

Excess cloth trimmed with chisel.





7 Fiberglassing the hull Once the interior work is done and the transom has been glassed, it’s time to flip the hull. To prepare the hull for fiberglass, I mix a small batch of epoxy thickened with fairing powder (micro-balloons). I fill all holes and gaps and once cured, sand with 150 grit sandpaper. I want to make sure all the edges are nicely rounded over. After sanding, I vacuum the board and wipe it clean. I’m now ready to lay out the fiberglass cloth. I lay one sheet on half of the bottom and down one side and another sheet on the other half of the bottom and down the other side. I want the sheets to overlap along the keel. On the Tango 17, a third layer right down the middle from chine to chine would probably be a good idea. After positioning the cloth I’ll trim off the excess, cutting a couple inches below the rub rail. I mix slow or medium curing epoxy and start wetting out the cloth. I like to use a disposable brush to spread the epoxy and carefully pull the cloth as I go to get the cloth to conform to the shape of the hull. I also use a plastic spreader to pull along any excess epoxy. After all the glass is wet out, I trim the excess at the rub rail with a utility knife. When all the cloth is wet out I immediately roll on a second coat. The goal is to start to fill the weave of the cloth. When this coat starts to get tacky, I’m ready to apply the fairing coat. I’ll mix another batch of epoxy and thicken it with fairing powder (micro-balloons) until it has a creamy consistency. The goal of the fairing coat is to build up a sanding layer. Adding microballoons thickens the epoxy and also makes it easier to sand. I want this coat to flow out easily so I don’t want to thicken it too much. If you can still see the texture of the cloth after applying the fairing coat, another coat will be required. When applying several coats of epoxy the general rule is that no sanding is necessary if the bottom coat is still tacky. However, if you let the bottom coat cure fully, you should rough sand before applying the next coat.

Filling gaps and holes with thickened epoxy.

Wetting out cloth with epoxy.

Applying second coat of epoxy with foam roller.







Hull sanded smooth and ready for glass cloth

Wetting out sides with disposable brush.

Applying fairing coat.









Laying out fiberglass cloth.

Excess cloth trimmed with chisel.

Filling and reinforcing underside of seats. 







8 Sanding & finishing After years of experimenting, I’ve found a fairly simple way to achieve a high quality finish. After the fairing coat cures there will be lots of material to remove. First I sand the hull with an orbital sander using 80 grit sandpaper. It’s important to keep the sander flat on the surface so as not to create any low spots or cut into the fiberglass cloth, especially around the edges. After the hull is sanded smooth and cleaned, I fill any holes or low spots and then apply another very thin coat of epoxy using a foam roller. This coat fills in the rough texture left by the 80 grit paper. When this coat cures I re-sand with 150 grit paper. This leaves a very smooth surface with just enough tooth for the paint to grip to. No primer is needed. While the hull is flipped, I’ll go ahead and paint the bottom. I like to use a one-part marine enamel applied with a foam roller. I get best results using Petit Easypoxy. It dries slower than other one-part enamels, giving me more time to smooth it out. I lay the paint down a little heavy so sections flow together. To remove air bubbles, I “tip” lightly with a soft bristle brush. I usually get a good finish with one coat but if a second is needed, I sand between coats with a 300 grit foam sanding pad. With the bottom painted, I can flip the hull over (being careful to protect the paint) and finish working on the interior. I still need to install the anchor locker faceplate and then the breast hook and cap rails. With everything installed, I want to make sure all surfaces are coated with epoxy and then start sanding. Like with the exterior, the best approach is to rough sand with 80-100 grit sandpaper, re-epoxy and then fine sand with 150 grit paper. On areas that will be painted like the cockpit floor, I can use epoxy thickened with fairing powder to fill and smooth. I like to paint the interior sides, bulkheads and cockpit floor with an off-white marine enamel and finish the seats with marine varnish or spar urethane.

Hull flipped and ready for sanding.

Hull re-coated with epoxy using foam roller.

Paint applied with foam roller and “tipped off”.







Rough sanding with 80 grit sandpaper.

Re-sanding with 150 grit sandpaper.

Hull painting complete.







Rough sanding complete.

Hull sanded andl wiped down with damp cloth. 

Painting underside of seats.







Hull flipped and ready for sanding.

Interior ready second coat of epoxy.

Sides, bulkheads and cockpit floor painted.







Rough sanding with 80-100 grit sandpaper.

Fine sanding with 150 grit sandpaper.

Seats finished with marine varnish.







Drilling hole for drain plug..

Seats taped off and ready for paint.

Painting complete. Ready for hardware.







9 Finishing Touches With the boat finished and on a trailer, it’s time to install the console, motor and hardware. I’ll start by installing the motor mounts and the drain plug. Now I can hang the motor. Next I’ll install the console. I like to use aluminum channels to attach the console to the cockpit deck. This allows me to slide the console forward or back if necessary. With the console in I can go ahead and install the steering helm and gear box and rig the motor. Finally I’ll add cleats, a bow eye, hatches and cushions. And that’s it. I’m ready to hit the water.

Motor mounts and drain plug installed.



Bow eye installed.



Hatches installed.

Console installed using aluminum channels.

Steering helm and gear box installed.

Console cushions installed.

Motor rigged.

Cleats installed.

Ready to launch.





Tango Plans L.L.C.

Post Office Box 4443 Chapel Hill, NC 27515 www.tangoskiff.com © 2015 Tango Plans LLC. All rights reserved.

