Q: I have a metal handrail that has some rust spots, including an area at the bottom of the hollow post where the metal has rusted a hole completely through steel. I tried patching it with JB Weld, but the epoxy keeps falling into the hole. Do you have any advice on how to fix this?
A: To fix a small hole in a hollow rail post, sand away the surrounding rust and use a metal file to enlarge the hole just large enough to fit the nozzle of a can of spray-foam insulation. Spray a little expanding foam into the hole. The foam will expand inside the hollow post and squirt out the hole. Once it has cured, use a razor blade to cut the stiff foam flush with the metal post surface. Then, use the epoxy to cover the foam-filled hole. If you plan to repaint the handrail, it’s a good idea to scuff-sand the epoxy surface so it will more readily accept paint.