banner for puddle duck racer boat

[ >> NEXT, My hull goes 3-D and gets its number]

Christine makes a Puddle Duck Racer

I Start Building My Puddle Duck Racer

I have quite a lot of odd materials so I'm going to use them up. In particular some very nice quarter inch baltic ply, sometimes called russian ply. The bad thing is that it comes in very odd sizes and is not 8 feet long. I will be joining plywood together using Dynamite Payson's butt joint method rather than scarf joints. (I have a page explaining scarf joints here.)

Joining the plywood

joining plywoodepoxy on edge

After thinning the edges to be joined slightly using a sander, the edges and sides are coated with epoxy. A strip of fiberglass is pressed in and coated with epoxy. After placing a layer of plastic wrap of wax paper another 2 pieces of plywood can be jointed on top of the first. Saves time and space.

photo of puddle duck racer being of puddle duck racer being built.

Some folks can apply the fiberglass on both faces at once then go on to the next 2 pieces and glue down the 2 faces of in one go but I prefer to let the epoxy set then carefully turn the wood over and then glass the second side.

photo of puddle duck racer being built.

A couple of clamps and some weights keep everything together till the epoxy sets. Usually there is not much touch up needed. A quick sand and rarely another coat of epoxy is all you need to do. If done carefully this joint is just about as strong as the plywood and all my sample broke at the wood rather than at the seam. It changes the bendiness of the plywood some but this is not relevant because I'm joining the side which have no bend and the bottom which has only a very gradual curve to it.

drafting the hull profile

Next step is to lay out the bottom profile. You can see the joint in the middle of the board. Once marked the sides can be cut. Here I only marked one side and clamped the 2 layers together to save some time cutting. It also helps ensure that the 2 sides are exactly the same. I have small screws holding them together as well.

Since I intend to make 2 side flotation chambers I also cut 2 extra profiles from very ugly underlay. It was warped and not very good wood. I just traced the already cut pieces on the plywood and cut the 2 extra pieces together. I put them all together to sand and finalize the edges.

Sides are cutchine logs glued and temporarily screwed.

Once the sides are cut they need a strip of wood called a chine log, applied to the edges. This is what the front, back, bottom and decks get fastened to. The wood is only a quarter inch thick so not enough surface area to glue on without the strips of wood (called chine logs) My lumber was so stiff I could not bend it, I finally split it with the table saw and glued the strips separately.

sides ready to assemble

After glueing and removing the temporary screws I cut and prepared the front and back pieces. Since I did not want to have to carry the boat upstairs I moved the boat yard to the back yard.

Cats are thrilled. They don't like the noisy basement shop but love the back yard.

photo of puddle duck racer being built.

I added strips to the front and back of the pieces and to the pieces that will be glued to make the front and back transom. I'm ready to join the pieces of the bottom together and put this boat together.

I have cut out the sides from baltic plywood I had left over from making my kitchen cabinet doors. It comes in panels 5 feet x 5 feet. This is 6mm thick and has 5 layers. It is heavier than the mokume I used for my Skerry but I had it. Since the Puddle Duck Racer is designed to be quickly built out of 4 x 8 feet panels I was sort of shooting myself in the foot using odd size plywood! I had tested it for waterproof qualities and it had passed the 1 hour boil test.

Just about any kind of plywood has been tried. Not surprisingly good plywood lasts longer and is easier to use while bad cheap plywood fails more often, has voids and warps. In between plywood can work very well though. Good quality exterior would be OK, marine ply is best. Don't use interior ply. The layers will delaminate because the glue is not waterproof.

Unlike the stitch and glue method of building, this boat is made by attaching small pieces of wood to the edges and gluing the panels to it. They are called chine logs. At 3/4 inch square they are not very big logs!

You can see my sides have the chine logs attached.

Gluing Bottom

Here I am gluing 2 smaller panels to make the bottom. I did one side, let it set then did the other side. I probably could have devised a way of gluing both sides at the same time but the delay was not important. It's been warm here and I found that the cling wrap I used actually stuck to the epoxy resin. I had quite a lot of trouble getting it off. This had never happened to me with this resin before.

I made the panel over-sized. I figured it would be easier to trim after rather than having to align perfectly. My epoxy was setting off very fast because of the warm weather.

I use thickened epoxy to glue the various parts together, many people prefer polyurethane construction adhesives. I think they have worked very well. I would not use it to join the plywood panels together but the regular gluing would work perfectly well.


emails: Christine

This web site reflects my personal ideas and doesn't represent anyone else's point of view.