I have just about finished the first two knives that I made from a bandsaw blade. The handles are osage orange and purple heart. Together, these two knives don't weigh more than a few ounces.
If you happen to find a gap between your handle slabs and the tang, you can fix this by mixing some sawdust into your glue of choice and pushing the stuff into the gap. This will form a nearly invisible filler and hide the problem.