To make straight marks on round objects like PVC pipe, keep it steady in the table saw’s miter slot, then make the marking across the table saw.
I’ve found that 1-1⁄2″-diameter PVC pipe, split lengthwise on my band saw, makes handy organizers in a shop drawer for my scroll saw blades. Drawing a straight cutting line on the curved pipe was difficult until I figured out this simple method: I set the pipe section in my table saw’s miter slot to hold it stationary, then drag a pencil across the saw table and the pipe. It gives me a perfectly straight line that’s also parallel to the pipe walls.
