I've got a massive load of logs dumped at my place for free. Finally found a tree guy. I bucked a few rounds, saw some sparks, and my chain is dull. No sign of metal. I did this a few more times, probably sharpened 4 or 5 times and gave up. Logs are super hard sugar maple, some is spruce, some ash. The logs have some ice and snow, probably with frozen dirt and rocks all around. Teeth definitely had chips taken out. There was a small piece of eastern red cedar that I saw a spark on and my chain was instantly dull, so I'm reasonable sure it's stuff frozen to the outside of the logs. I've sometimes cut several cords of wood without sharpening before. My thought is to get a 16" piece of wood, mark the cut with a hatchet, then go around the top part of the log with the hatchet, and after rolling use the hatchet for the other side. Any other ideas, thoughts, etc? P.S.:bar oil is getting used, and I've set to max just in case.