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Any advice on technique with the splitting axe? Use the same way as the maul?
I thought I'd need a heavy maul for the large rounds, but I use the axe for everything. On the larger rounds, start at the edges and work your way around. One nice thing about working in from the edges is that the edge pieces with bark are thin and have lots of split surface area, and all the inside pieces have no bark. So everything dries faster. I don't have any trouble missing strikes with this method.
The knottiest pieces for me tend to be spruce rounds from mid-trunk. I use the axe to get as much off as I can, and then either stack the larger knotty pieces in one area and burn them whenever they've dried enough, or use the chainsaw to cut through them one more time.
I haven't picked up my maul in 3 years.