When sawing any, but in particular plastic pipes (due to its “softness”) to withstand the cutting line is exactly perpendicular to the axis (or if necessary – on the contrary, under the right angle) will help the duct tape. Wound appropriately a ring from it will not allow the cutter to get off.
Recommend to read
VISOR FOR SUN LOUNGER
Nice to soak up the sunshine, sitting in a lawn chair. However, it would also be good to read, it's very blinding. Make a movable shelter made from fabric and pieces of wire,as shown...
FRAME TO THE MIRROR
MATERIAL: metal rod Ø3 mm, a rod of square cross section 8X8 mm, flat metal section 2X15 and 3X15 mm, plywood 10 mm thick, thin plywood, mirror, screws 4x10 mm, colorless furniture...