craftgrrl | Finishing rough wood? Please Help!!!

This may seem like an odd question, but it will probably make more sense in context. I need to know the best way (or if there IS a way) to varnish or otherwise protect (not stain) wood.

So I'm sending out a special small swap package to a member of our group that got shafted last month, and I'm making her a set of runes! I have had this branch (which I found in my yard one day while mowing the lawn, and do not know where it came from--it looks like someone used it to shift logs in a fire or something similar, as it is blackened at one end) in my garage, because it called to me to keep it. When I saw that she needed a set of runes, I knew why. So, of course, I got out the handy dandy hand saw, and started hacking away at it.

Now I have a bunch of round, similar, rough disks. I don't want to sand them, as I like the rough texture to them. The bark is prone to peeling off, but I'm hoping there is some form of varnish or something that I can use to keep them a little more durable for casting, and so they won't give her splinters every time she reaches for one. The runes, by the way, will be burned onto them as soon as I purchase myself a wood burning kit. XD Yay for new experiences. I just hope I do all of this right.

The cut pieces (20 down, 4 to go):

So, what's the best way to varnish these, or whatever? What should I use, and how should I go about doing it, considering how small the pieces are? Any ideas? Any bit of insight, related to the finish or to any other part of this project, would be GREATLY appreciated. Please help, ladies!!!