How to do a bullnose with a roundover bit?

[Louis Brandt]

Hello,
If I want to put a bullnose or at least a partial bullnose (maybe with a small fillet on the top and bottom) along the edge of a five foot length of 1x6 oak, and if I want to do this using a roundover bit instead of a bullnose bit, can anyone tell me how to do this? If I use a roundover bit with a bearing to follow the edge, how can I avoid the problem that will occur when I have no "edge" for the bearing to follow, once I turn the piece upside down to roundover the other side?
I don’t think that I can do this with an actual bullnose bit. I have a router table but no router for it yet, and the old Craftsman router that I do have won’t fit the router table, so I will have to do this operation by hand. I realize that I’m a router newbie, but I don’t think that there’s any way to use a bullnose bit without a router table. If that’s correct, I’m stuck with trying to do it by using a roundover bit and rounding over both sides.
Any help will be appreciated.
Louis

[Jamie Buxton]

If you're insistent that the profile be exactly a semicircle, you're right it is difficult to do with a roundover bit. Do you really need an exact semicircle? You can do two passes with a roundover bit of a radius one size smaller than the semicircle's radius. That gets you a bullnose with a slight flat spot in the middle. What's wrong with that?

And if the slight flat spot in the middle bothers you, you can remove it in the sanding stage. Rock your sander a little, and the flat spot goes away. Okay, you don't have a perfect semicircular cross-section, but nobody can tell without careful measurements.

[Norman Hitt]

Louis, make a "Temporary" router table for your Craftsman router, by drilling a hole, (slightly larger than the roundover bit or Bullnose bit you are going to use) in the center of a small piece of plywood (maybe 18" x 30"), then drill 3 or 4 mounting holes to attach the router to the plywood and install the router. You can then lay the plywood across two wooden sawhorses, and screw the plywood to them, then make a Temporary Fence, by taking a straight piece of wood/MDF, or other and trill a hole about the middle of it so that it opens on one side to allow the bit to enter, then clamp this to the "Temporary" Plywood router table, and you're in business. ;) :)

[Norman Hitt]

Louis, make a "Temporary" router table for your Craftsman router, by drilling a hole, (slightly larger than the roundover bit or Bullnose bit you are going to use) in the center of a small piece of plywood (maybe 18" x 30"), then drill 3 or 4 mounting holes to attach the router to the plywood and install the router. You can then lay the plywood across two wooden sawhorses, and screw the plywood to them, then make a Temporary Fence, by taking a straight piece of wood/MDF, or other and trill a hole about the middle of it so that it opens on one side to allow the bit to enter, then clamp this to the "Temporary" Plywood router table, and you're in business. ;) :)

[Vaughn McMillan]

I second Jamie's suggestion. I've done lots of bullnose-edged cutting boards, most of which are 3/4" thick, and I use a roundover bit set just a little bit shy of half the board's thickness. Between sanding with a ROS and hand-sanding (using a full sheet of sandpaper on the edge as if I was buffing a shoe), you can get a nice, smooth bullnose. I use a router table, but it could also be done with a handheld router. Just be sure you have the board secure so it doesn't move when routing the edge.

40548

- Vaughn

[John Lucas]

Norman's idea is a good one. You can also use an edge guide fastened to your router. That would allow you to use a bullnose bit or roundover bit and top and bottom pass.