In the book Hatchet, how did Brian solve his raft problem?

Brian used logs that had branches protruding from them instead of clean logs, so he could bind them together more easily.
Brian needed a raft to reach the plane, where the survival pack was waiting for him.  He knew that he would need to make the raft himself, but he was not sure how.  Brian was able to find the logs, but he wasn’t sure how to combine the logs into a raft.

Keeping them together was the problem. Without rope or crosspieces and nails the logs just rolled and separated. He tried wedging them together, crossing them over each other—nothing seemed to work. (Ch. 17) 

Brian decided that the problem was that the logs he was looking at were smooth, and he needed logs “with limbs sticking out.”  He found some like that, and proceeded to “weave” them together.  He named his raft Brushpile One.  Then he had a new problem.  How would he keep it from floating away? 

Then he remembered his windbreaker and he found the tattered part he used for an arrow pouch. He tore it into narrow strips and tied them together to make a rope or tie-down about four feet long. It wasn't strong … but it should hold the raft to the plane. (Ch. 17) 

The other problem Brian had, once he solved these two problems, was that the raft barely moved.  It was dragging from its weight.  Brian decided to be patient, and turn back and try again in the morning when he had more strength.  Building the raft had taken a lot out of him. 
Brian’s work with the raft demonstrates a great deal of personal growth, which is something even he realizes.  He understands that he needs patience. He is able to stop and notice the beauty of the lake.  Brian is able to put things in perspective.  He is thinking about solving problems, and able to find solutions, without getting as easily frustrated as he used to.