Hi CM,
I cut my teeth in the logging business in the early '80s. Back then it was in logging camps 60 or more miles in the woods with a camp cook, and a generator for power that was shut down at 9:00 PM. I still remember laying in bed on quiet -20 F nights and hearing trees split from the cold so loud you thought it was a rifle shot.
Any way, after supper (or dinner depending where your from) we would all go out and work on our saws for the next day. This was when I paid attention to how the "big choppers" filed. One older Canadian showed me a few things that made a huge difference.
1. New or real good file. You can't get it sharp with a spike.
2. He would allow his file to ride high on the tooth setting the angle and get a nice straight edge on it removing any roundness from the corner. Only a few passes.
3. Then he would file applying pressure down and back towards the saw. "The top of the tooth has to look like the visor on your hat" he said in french. "It has to make chips not dust". This was done until he saw a paper thin flap of steel form on the edge of the tooth. It will NOT get any sharper than this.
Depending on its condition, it only takes maybe 4-6 passes and and a few seconds per tooth.
Raker hight would depend on the wood your cutting.
Another thing he showed me is to get used to filing with both your right and left hand. It seems odd at first but I soon got used to it and it keeps you from getting different angles from one side to the other. I don't think I ever saw anyone else do this but it did help me.
Remember,the file is a cutting tool. I keep mine in a short piece of gas line to protect it in the tool box.
I haven't needed a saw to make a pay check for over 20 years but I cut firewood on my wood lot and what I learned on that pickup tailgate years ago serves me well today.
I don't know if I've put this in a way someone can understand but it is easily shown in person.
Practice, practice, practice!
Good luck. Dan.
