I made the mistake of underestimating the splitting power of my Fiskars X25. My first attempt went right through some oak and hit a rock just under the soil. I needed a chopping block. I don't have any large rounds and most of mine aren't level, so its been a bit awkward for me so far. I've been balancing two rounds on top of one another. It works but I'm always straightening things back out. What else could I use as a chopping block? How would birch plywood hold up? I could glue a couple of 3/4" thick 2' x 2' pieces together??? Would that work or would it just be temporary at best? Thanks!