Need to surface plane large pine slab for a bar

[FoxtArt]

Secret: Make a large jig (wood frame, levels, metal, whatever) that is perfectly straight. Then make another jig that you can slide a router on. Basically, imagine it as a large typewriter, where the wood is your paper - but leave it static, and slide the router around. Zig your router back and forth on the sliding jig and you'll plane it reasonably well. Then use a belt sander to finish it smooth. The quality of the cut is dependent on the edge of your main frame/jig. So something with perfect edges is recommended.