Raingutter Regatta Boats

The Raingutter Regatta is similar to the Pinewood Derby or the Space Derby except that the models are miniature sail boats. Although the seas are only 10-foot lengths of raingutter filled with water, and the ships a mere 6 inches long, the race is a very exciting event. Each boy builds his own boat with supervision and help from parents or other family members. He also provides the wind for the sail with his own lung power.

The regatta boat kit, available from the Scout Shop, has a pre-shaped balsa hull, metal keel and plastic sail. The hulls are sanded and shaped, and are colorfully painted. Hull and sail are then decorated with decal kits (also available at the Scout Shop). The boats race in pairs on raingutter courses propelled by the boys blowing into the sails. The races can also be run as a team relay event.

This discusses a roll your own version of the raingutter regatta kit that can be constructed for $.50 to $1.00. At this price point, it's possible to do a boat building as a daycamp activity or as a recruiting activity for tiger scouts -- the boats are easy enough for kindergardeners to assemble and cheap enough so you can give them out to an entire class (both boys and girls).

Bill of Materials:

Item	Cost	purpose
2"x3/4"x6.5" Balsa block	0.35	boat hull
lead sinker, 3/8 - 1/2 oz.	0.15	keel weight
3/16" bamboo skewer	0.02	mast
milk jug plastic	0.00	rudder
laminated paper	0.05	sail
total	0.57	--

Item names link to sourcing information

Implements of Destruction:

Drill Press	Band Saw	Hot Glue Gun
Belt Sander	Fine tooth saw	Laminator optional

Don't worry if you don't have a bandsaw, belt sander, or drillpress.
There's almost certainly someone in your pack
who takes the pinewood derby waaayy too seriously.
They'll have these tools.

On the other hand, if you're a person who takes the pinewood
derby waayy too seriously, bandsaws can be purchased on
clearance at Lowes or Home Depot for under $100.
A drill press will run about $40. Both are awkward to move
and will take up valuable space on your workbench.

Hull Construction

2"x 3/4" balsa stock may be purchased in 48" lengths. The boat hulls are about 6.5" long, so you can make 7 hulls from each 48" stick. Print out the hull template, trace it onto the balsa stock, and rough cut 7 hulls with the band saw. Repeat as needed to get the quantity of kits you need. Take a break every half hour. Balsa cuts very easily and you should be able to rough out a dozen hulls in 10-15 minutes.

Link to Hull Profile pattern

Roughed out hull

Sanding the hull

The next step is to sand the cut edges of the hull on the belt sander. Use a medium or fine grit belt. The balsa is very soft, so one or two passes across the belt should be enough to smooth out the marks left by the bandsaw. This step produces a lot of dust, so do it in your garage or outside if possible.

Use the mark on the hull pattern to mark the spot where you will drill a hole for the mast. Use the drill press to drill a 3/16" hole through the hull. You can probably do this with a hand drill, but the drill press is a bit faster and more consistant. To speed things up, mark all of your hulls at once and then drill them all in a group.

Comments:

Soft pine can be substituted for the balsa. It's often cheaper and more readily available, e.g. you can resaw a 2x4. The disadvantage is that the pine hulls don't float as well and pine takes longer to cut and sand.
The key to making hulls in quantity is to do the steps in batches. Trace out all the hulls in one step, then do all the rough cuts, then do the sanding, then drill all the holes.
You may need to use a larger/smaller bit than 3/16". Experiment. The bamboo skewer should be snug in the hole, but not so snug that a lot of force is needed to push it through the hole. When the balsa and bamboo get wet, they'll swell and fix the mast tightly in the hole.

Making the Mast

A 3/16" bamboo skewer is used for the mast, the lead sinker is used as a keel weight. The mast extends 6.5" above the deck of the hull. You'll need about an inch below the hull, so cut the mast to 8" to 8.5" -- cut the blunt end of the skewer not the sharp end. Take the lead sinker, drill a 3/16" hole in it, stick the sharp end of the skewer through the hole, and smash the sinker with a hammer. The lead in the sinker is soft and will deform and grab onto the mast when you smack it with a hammer. The sharp point of the skewer will usually poke through the hole in the sinker. Just snap it or cut it off with scissors.

more pictures to follow

Making the Sail

You can have a lot of fun with the sail. Use light card stock paper. You can print designs on them or have the kids color the sail. Then laminate the sail to make it stiff and water resistant.

Preprinted Sails composed on MS Publisher

If you're on a budget, sails can be made from any plastic laminate material. For some reason our scouts were very amused by sails cut from outdated Ohio Labor Law posters . . . go figure.

Link to Layout of 3 sails on a 8.5"x11" page

Drilling the holes

For Pack 365's events, we printed sails, 3 per page, on light card stock and then laminated. These were cut out before the event. Holes were made for the mast by stacking 2-3 dozen sails and drilling the holes on a drill press using a bit appropriate for the skewer size.

Installing the rudder

Cut a rudder from milk jug plastic using the pattern below.

Link to Rudder Pattern

Cut a slot in the hull

using a fine tooth saw

Cut a slot in the bottom of the hull using a fine tooth saw. Slip the rudder into the slot and secure it with a bead of hot glue.

Assembly

At this point you should have a mast, sail, and a hull with rudder. Insert the mast through the hole in the hull and slip the sail down over the mast. This is enough to keep the average kindergardener busy for about 5 minutes -- which is about the limit of their attention span. When you sail the boat, the water will swell the wood and bamboo so that they won't slip.

pictures to follow