You don't have to be that accurate when cutting a piece of drywall / gypsum board / sheetrock. Within 1/4" is usually fine. Mud and tape covers a lot of evils. Fitting pieces in odd-shaped areas like angled soffits or ceiling transitions, or anywhere in an old house can be a real challenge though. When I refinished our baby room, I don't think there was a single square corner in the whole job. After cutting a funky piece based only on the dimensions and finding it was off by over an inch, I went down to the shop and made these.
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| Three foot angle gauge for drywall |
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| Simple but effective lock mechanism |
They're nothing more than a couple strips of thin plywood, held together with a short carriage bolt and a wing nut. I glued a patch of 160 grit sandpaper to one of the pieces at the joint, which really helps them lock together when the wingnut is tightened. I made two sizes to accommodate my work, one about 3ft long, and the other about 18 inches.
To use them, just hold them up against the corner you need to fit, and then lock the angle. Lay the gauge on the piece of drywall and mark your cuts. By taking angles at all the corners and making sure all the angles and side lengths were correct, I cut a lot of weird triangles and trapezoids to very close tolerances. Super handy.
