round plywood corners with round edges... how do I trim it?

[Shoshi Fein]

I am trying to build a shelf that has a round corner and all of the edges are rounded but I can't figure out how to trim it. Any suggestions?

[Bill Houghton]

If you mean shape it, I've usually been successful with the appropriate diameter roundover bit in a router, run all ways followed by some sanding. If you don't have the router or the right roundover bit, a rasp or file (watch grain direction so you don't blow out a ply or two) followed, again, by sandpaper should work; if the radius is large, nibble off a bit with a fine toothed saw before you begin.

If you mean covering up the plywood edges, it's probably better to cut the plywood square and cover the edges with solid wood of sufficient dimension to get all your rounding done in the solid wood. For non-structural applications, glue alone always surprises me by its strength, but deeply set nails with the holes patched or one of the several tongue-and-groove approaches would be better.

If you mean something other than these, speak on.

[Shoshi Fein]

I am going to cut the edges square and glue or nail a trim on. the problem I am having is that the edge is round and I am not sure how to trim the round edge so that it matches the trim on the straight edge... did I describe that clearly?

[Jay Jolliffe]

Laminate thin strips until you get the thickness your looking for. I guess it depends on how tight the corners are.

[Shoshi Fein]

The top edges are rounded which is why I wasn't sure about laminating strips..

The only solution I was able to come up with is to cut all of the trimming from 3/4" wood. I am cutting all of this on a CNC router so I would be able to match the curve exactly, I was hoping to find a different way to match the curved trim to some other straight trim but it looks like I will have to cut all of the trim.

Thank you for your help all! If you have any suggestions or advice I am all ears!

[Bill Houghton]

If you're painting it, it's sometimes possible just to fill the plywood edges with spackling, Bondo, or something similar - I'm told. I've never trusted this approach, because end grain seems like it would be inevitable, and end grain finishes very differently from long grain.

Still, if the project proves difficult otherwise, and you're using a painted finish, you might consider this approach.

[Chip Lindley]

What radius curve are we talking about on the outside edge of this shelf corner? If you are gluing or nailing on solid wood trim, I cannot visualize the radius very large. (3/4" half round?) The outside diameter of the corner could be sanded. But you would need a router bit matching the trim profile to match the profile around the outside diameter. As said before, hard to visualize without dimensions. Here is a pic of small radius trim I made on a bath vanity, mitered and rounded over with 3/8 bit.