Materials: IKEA Melodi Lamp Shade, Plywood Base Board, 2.5" Galvanized Pipe, Foam Strip, Modeling Clay, Silicone Caulk, CHENG Outdoor Pro-Formula, 100+ pounds Concrete Mix
Description: The IKEA Melodi lamp shade makes a perfect concrete mold for an umbrella stand. It's cheap, attractive, re-usable, and comes in two sizes.
The first step is to drill a 2" hole in a plywood base. A PVC or galvanized pipe fits in the hole, then the lamp shade slides over the pipe and onto the base board.
A small wooden frame is built to hold the lamp shade in place, and some modeling clay and silicone are used to seal the form at the bottom.
Filling the form with concrete is the easy part. Wait a few days for it to cure before taking the concrete out of the form, then cut the pipe down with a hack saw, polish the top of the concrete, drill a drainage hole and install some furniture bumpers to protect the concrete and the floor.
The finished umbrella stand weighs about 100 pounds, making it stable enough to hold the biggest umbrellas.
Check out the Instructable in the link for the full step-by-step.
~ CHENG Concrete, Berkeley, California, USA