A guy at the lumber yard kept telling me to try a 1/8 inch roundover bit on my plywood edges

I mean, I always thought it was a waste of time and would look cheap. Last month I was finishing a built-in for a kitchen in Springfield and decided to try it on a scrap piece first. After a light sanding and a coat of paint, the edge looked totally solid, like a finished panel. It completely changed how I handle plywood edges now. Has anyone found a different bit profile that works better for painted work?

4 comments

4 Comments

markh851mo ago

Wait, are you sure about that 3/32 bit? Ive run a lot of painted plywood and 3/32 is actually 0.09375 inches. A 1/16 is 0.0625 and 1/8 is 0.125. So 3/32 is almost right in between those two. But Ive never heard of anyone using that size on purpose. Most router bit sets skip over that size entirely. The industry standard is basically either the 1/16 for that real sharp modern look or the 1/8 for a slightly softer edge that still hides the layers. If your foreman really used a 3/32 bit he probably just grabbed whatever was in the drawer and it happened to work. But the 1/16 is way more common for paint grade stuff in my experience. That tiny radius is key for keeping a crisp line on cabinets.

susanb343mo ago

Yeah, that roundover trick is a game changer. I read a forum post a while back where a cabinet maker swore by a 1/16 inch roundover for paint grade work. He said the smaller radius leaves a sharper look that still hides the plywood layers perfectly under paint. I tried it on some shop cabinets and it worked great, maybe even a bit cleaner than the 1/8 inch for a more modern style. It's such a simple fix that makes plywood look so much more finished.

diana5123mo ago

My old foreman at a custom shop in Boise insisted on a 3/32 roundover bit for all painted edges. It was this weird middle ground that gave a crisp line but completely erased the plywood lines. We used it on miles of built-in bookshelves. The finish guys loved it because primer would fill any tiny tear-out without losing the sharp look.

stellaperry3mo ago

My uncle's shop in Tacoma had a dedicated 3/32 bit just for that, they called it the "paint saver." That trick susanb34 mentioned really is everywhere.