I want to drill out one of the screw holes for my drain plug, as there is evidence of water intrusion. I wondered if I can just clean it out, fill it with epoxy, drill a pilot hole, and put the screw back in? Or do I need to tap threads?
Jake's over thinking this.
Let the hole dry out. Clean it out with a pipe cleaner wetted with acetone.
Use thickened epoxy (JB Weld works fine for this - hard to measure this small amount of WEST) to fill the hole. Use a toothpick as an applicator and make sure the hole is filled with no air bubbles. Put a piece of tape over the hole to keep the epoxy from oozing out.
Several beverages later, peel off the tape, drill a pilot hole for the screw (no tap unless it's a machine screw) and reassemble with a dab of silicone around the drain plug housing. Don't overtighten the screws.