Precision straight edge

[Brad Hall]

I'm at the stage where I'll begin dressing the frets. What do you use for a straight edge? I see many machined beams in various lengths and widths for sale. Prices from about $50 to $150. What I'm seeing has me leaning toward a 18" X 1" aluminum beam. I would appreciate your insight. Cheaper is high priority for me. I do have a 22" sq. granite slab that I have considered taping sandpaper to and pushing the bolt on neck across. Only drawback ( I see) would be the fretboard extension that would not touch the table.

[ken cierp]

Why not just joint a piece of hardwood and make sure it lays flat on your granite slab? Straight edge is the key not the material its made from. Lots of guys/gals use an aluminum level.