That’s a good video for people to watch 74! If you are going to heat with wood, any plan to use chain saw or even electric you can recharge, you need to learn this. I’ve been cutting a lot of wood this summer as I have time and have to do this fairly often, doing almost ‘production’ cutting as we have been. If you go to a repair shop you can get an old chain from the mechanics to practice on first. It’s a tedious job but necessary.