I made a benchtop that includes my radial arm saw out of MDF. What is the best product to use to seal or finish the MDF?
Tim Inman: Short answer: Formica. Longer answer: Plastic laminate. Really. This is a great place for a melamine, mylar, or phenolic type laminate surface. That said, virtually any sealer will work. MDF is like a sponge, so it will soak up quite a bit of finish at first. Let it drink, and be prepared to apply more than one coat. Scuff sand, then recoat to get a smooth “gliding” work surface. Here’s another tip you might consider if you’re wanting a surface that will let the work slip and slide. Floor sealers made especially for bowling alley maintenance usually include some “slipping” agents to keep things moving along. They are very tough, and quite durable. I once used such a product that had powdered Teflon® included in it. It made a great working surface. Check with flooring contractors or your local bowling alley to find a source.
Chris Marshall: I’ll take a different approach from Tim on this one – but I don’t disagree with his reasoning. If this bench isn’t one you plan to hand down to the next generation, and it’s just a workaday shop fixture, a finish isn’t absolutely mandatory. Adding a protective topcoat will make glue drips and other shop liquids easy to clean up, no question about it. But, MDF actually has a pretty durable surface all on its own. I’ve had a worktable in my shop with an MDF top on it for at least a decade, and it has no finish on it. It’s still going strong. I recommend that you edge your bench with hardwood. MDF’s edges aren’t nearly as tough as the faces.