I spent a few hours in a big box hardware store thinking up a design from what I could find there. I used 3/4 in schedule 40 PVC for the frame and decided to try to make a plastic shoe organizer that hangs on your door the method of propulsion. I got really excited to try to make this concept work so however much this build ran into stumbling blocks along the way, it became about trying to prove if the shoe organizer would work to push me along the water.
Step 1: Drawing Board
Step 2: Materials List
2- 1"×2"×8' wooden strips
8- 5 gallon lids
2- 6" ×24" long galvanized steel ducting
2- 10' 3/4 schedule 40 PVC
6- 45° PVC connectors
4- 90° PVC connectors
4- T PVC connectors
2- cans spray foam
1- box 1 inch screws
4- pool noodles
some type of rope to make transport straps
Step 3: First Build
2&3) Mark off on the metal ducting the width of one of the halves. Draw on the width again leaving enough room for leftover length to be made into flanges. On the material you left for the flanges, draw relief cuts about every two inches so you will be able to bend the flanges. Repeat the markings on the other ducting.
4) Cut out your four cylinders and the relief cuts. Use a jigsaw with metal blade, a hacksaw or tin snips (least recommended). Bend the flanges out with channel locks or with a hammer over a hard edge. (Disregard the foam inside the cylinder in the picture. You will add foam in there later but I was testing out how far one can of spray foam would go. It just gets in your way to do it now.) Drill holes on three of the flanges per side of the cylinders. If your edges are sharp, try to take the burrs off with a file.
5) Cut your 1"×2" wood stock down the middle to make 1×1 square strips and then cut them to length. You will need 28 strips 9" long.
6) With a 1 1/8" hole saw, or draw and cut with a blade, make center holes in each of the lids. Center each side of a cylinder on a lid and mark and drill the holes from the flanges. Rivet two of the cylinders to their ends. With the other two and their lids, mark which goes with which side and set aside.
7&8) Pre-drill four wooden strips one inch from the ends and then drill and bolt them on to two of the cylinders 180° apart from each other. I lucked out that the length of one shoe pouch was half the circumference of the 6 in ducting. Then on the inside of each shoe pouch loop (the side without pouches), staple a wooden strip at the bottom edge of each pouch. These will act as cleats for your pouch loop. Stapling over the taped edge where the two strips meet will also secure the seam.
9) Put together your peddle assembly on a flat surface. You want this too all be on the same plane. Once all the connectors are pushed on as far as they can be, drill holes at each junction and put a 1 in screw in each to secure them. They make PVC cement that would be even more sturdy for this but I wanted to be able to edit all the lengths. You will repeat this locking process with screws all over the PVC junctions after you have it all assembled (Step 13).
10&11) At the ends of your peddle section of PVC, attach the t connection, small ends and caps. Since each cylinder will be slightly different because bending the flanges made them not perfectly round, place the assembly inside to make a more precise measurement. Once you've centered it, drill holes at all junctions and put in one inch screws to lock them in place.
12)Cut a slit from the center of the lid almost the the edge on only two of the remaining lids. Push the t assemblies from step 9 through the lids, then rivet the lids to the flanges.
13) This step requires a mixture of good guessing and measuring. You want to drill into the cap on the t assembly through the outside of the cylinder. Use the slit you made in the lid to try to see where it is and then try to drill into it. A few extra holes won't hurt the build.
14) Slide pool noodles over all frame sides. This step is sticky so wear gloves: into one of the holes of the each cylinder, spray the foam. It will expand to about double the size so estimate how much each will need to be filled. I used about 1 and a half cans of Great Stuff for all four. You will want to do the next step quickly while the foam is still wet. Assemble the rest of the frame, pre-drill and add 1 in screws to all junctions. Make sure you put the shoe pouch loops on the cylinders before you assemble it. Once the foam has dried, rotate each cylinder to break the PVC free of the foam. It won't take much force to break it free.
15) I added a few pool noodles as a seat by running clothes line rope through their centers.
Step 4: First Test in the Water
https://youtu.be/NUIOAouisHc), I weighed the craft down too far in the water and was getting a zero displacement effect with the pouches. I also found that they didn't open as readily as I had hoped.
Step 5: Second Attempt
The craft floats much better and there is a definite forward motion. The way the peddle section is constructed is still too flimsy and without real peddles, but still pushed me forward in the water against the current.