I got some used butcher block table tops that I am sanding down and want to use for bench tops. What have you guys been using on the tops to protect them. I want to seal them from fluids in general (brake clean, gasoline, oil,etc.). I am concerned about a thick clear coat chipping when I put a transmission, or engine block on it. What do you think?

You're going to the trouble to sand it down to get it to look good but don't want to put a clear coat on top for fear of chipping, but then toss a transmission or an engine on it? It looks to me that if you don't have a piece of steel on top to protect it, then no matter what you do is prety much a lost cause.