I made this kayak last summer, but I have just recently joined Instructables. This will be my first time doing this so bear with me if my instructions aren't perfect. I really enjoyed making this and I also enjoyed riding it. It turned out to be quite stable, enough that I could stand in it and not have it flip. I made this kayak out of PVC pipe, duct tape, and garbage bags. The kayak is close to the water but I didn't have problems with water coming into it. The kayak looks kind of flat at the front because I wrapped it up too tightly and the front got squished. That means that your kayak could end up looking a lot better than mine. The kayak still worked perfectly. I just used paddles I had from a rubber raft and they worked fine until half of it broke and we couldn't find it. Sadly I didn't take many pictures so this instructable will be lacking pictures.
For this project you will need:
-5 pieces of 10' 1'' PVC (it can be a different size then 1'' but if you do it to much bigger it could be hard to bend)
-PVC pipe cutters
-4 elbow connectors
-12 T connectors
-Some garbage bags
-piece of wood (for seat, you could use other stuff too)
-And lots of duct tape (I used around 7 rolls, but you might need more or less depending on how you wrap it. 3 of those 7 rolls were gorilla tape to make sure it was strong but you could probably use normal duct tape).
During this instructable I will tell you better ways to make your kayak than I made mine since I didn't have much of a plan while I was making it.
Step 1: Making the Frame
Using your PVC cutters, cut about 4'' off two of the four PVC pipes and then connect the two 9'8'' with two elbow connectors. Do the same with two of the 10' long pipes (you may want to duct tape the elbow connectors to the pipes so they won't slip). Attach the two pieces together by taping their points to each other. This will make the kayak curve up which is good.
Cut two 8'' pipes out of the 10' pipe. Put them at about the center of the kayak at opposite sides and then connect them to the rest of the frame with two T connectors each. Out of the 8'8'' pipe cut two 2' pipes and use four T connectors to put them at about equal distances from the 8'' pieces on the the bottom part of the kayak (the part that curves up). From the 4'8'' cut two 1'6'' pieces. Use T connectors to put them on opposite ends of the kayak at points where they fit snugly.
Tips: When using the T connectors you will need to cut the pipe and you may want to tape the connectors to the pipes so it won't slip. Also it would be a great idea to look at the picture so you can see where things fit.
Step 2: ADDING GARBAGE BAGS
You can use other plastic materials, I just used garbage bags because I had plenty of them. You can make them longer by cutting them down the sides (you don't need them to be thick, you will just put duct tape over them later). Then you just attach them everywhere over the frame as tight as you can (leave room for you to get into the kayak). I don't have any pictures of this step, but it is really simple and easy to fix. You can just tear bags off of it if you put them in the way of where you want to get in. This step is to make it easier to attach the duct tape and and so there will be no stickiness on the inside of the kayak.
Step 3: PUTTING ON THE DUCT TAPE
In the picture you can see that the front is flat this can be avoided by putting on strips of duct tape side to side and up to down. Don't wrap it around (I was stupid enough to do this at the front and that's why the front looks flat, although it still floated fine). I put on a layer of duct tape and then I used gorilla tape to make sure no water would get through and to make it durable. As I said at the beginning you don't need to use the gorilla tape, but I would still recommend adding the second layer.
Step 4: FINAL TOUCHES
You can add a seat if you want to. I just put a piece of wood in it and put tape over it so I wouldn't get slivers. You can put tape inside the kayak. I put some in, but then ran out of tape and it wasn't all that important to me so I just left it as it was.
Thanks for reading my instructable. I hope it was of some help to you