Building a Raft
A raft is almost always constructed from a combination of materials that are naturally buoyant. These include foam, plastic barrels or bottles, wood and other types of flotation material. These materials do not need to be watertight to float, however, they must be held together with rope and/or ratchet straps to prevent them from shifting or falling apart as the raft goes through the rapids.
If you do not have a lot of time to construct your Floßbau and you are looking for something quick and easy you can use a simple barrel raft. These are popular at raft races and consist of a few barrels attached to each other by bungs. A carpeted deck is then added and the raft can be rowed using oars that are fastened to the back timbers. These oars can be a bit heavy for young children to handle so the raft might not perform as well as a professionally built one, but it is still very fun and an excellent way to teach kids about the fundamentals of rafting.
For a raft that will last longer and be safer to use consider making it from a more sturdy type of material. The three main rafting materials are PVC, polyurethane (or urethane) and Hypalon. PVC is the least expensive of these, but it is not as tough as either urethane or Hypalon. It is also brittle in the cold and susceptible to UV damage. One exception is the Aire brand of raft which has a PVC exterior that is zipped over a urethane bladder.
What Materials Are Commonly Used in Building a Raft?
Other companies such as Maravia in Boise make a raft of high grade PVC that is then covered with urethane. These rafts are very strong and have a nice clean look to them. They are not as light as a Sotar raft but they aren’t incredibly heavy and have the advantage of a durable matte type finish that does not show up scuff marks so easily.
Before you start working on your raft make sure you have the right tools to do the job. You should wear safety glasses when handling any power or hand tools. It is also a good idea to have someone supervise you when you are cutting anything so that no one gets hurt. Lastly make sure you have access to a body of water that is deep enough for the logs to float; about calf-deep is fine.
Once you have your materials it is time to assemble your raft. It is important to cut 2 in (5.1 cm) notches into each of your logs. These notches will help the logs fit together better and make it easier to secure them. If you do not want to take the time to cut notches use a hatchet or other tool to punch holes into both ends of each log.
When you are done assembling your raft roll it towards the water. It may be a bit awkward at first but as you get used to moving it by rolling it will become easier. You should not try to drag a completed raft across dry land as this can cause the logs to crack and break.