I'm quite adept with a chainsaw and have heard good things about the beaver blade and would like to try one on my Troy-Bilt brush cutter. However, I'm curious about the chain on the beaver blade. I'm well aware that chains on chainsaws need frequent tightening when new as they loosen up with use. Does the chain on a beaver blade get loose and need to be tightened? If so, how does one tighten the chain? Over time, when the chain is eventually sharpened down to nubs and needs to be replaced, is it difficult to replace the chain or is it more advisable to simply replace the entire blade? Thanks for any useful information you can give on this subject.