Need some help with routing a bullnose on a deck railing

[jihhwood]

A friend has just built a deck and he's asked me to help him rout a bullnose on the railings.  I'm a furniture maker and have used a router for profiling edges (chamfers and round-overs) on table tops and such.  I've almost always used a fence to guide the router, though I have used bearing-guided bits successfully now and then.  Can you walk me through the process of routing a bullnose on an installed deck railing?  How is the cut set up?  I presume that the bullnose bit is bearing guided.  But along which part of the edge does the bearing ride?   I've looked for a good video on YouTube without success (many focus on profiling a granite counter top, and I'm not sure how much of what they say applies to my project).  Thanks in advance.

[Stwood_]

Router should ride on the top (the widest part of the railing normally) with a bearing guided bit.

[museumguy]

If I understand correctly, You want to rout a bullnose profile on the edge of some railing. On my deck, I used 1" thick material and used this bit, https://www.amanatool.com/57190-carbide-...shank.html . I routed the bottom side before installing the railing. This won't work if the railing is already installed. Amana makes other radius' as well.

[MstrCarpenter]

I just searched Google for "double roundover router bit". My quick search didn't reveal any with a 1/2" radius, but I saw a 3/8" radius that would do stock up to 1-5/8". You may have better luck. I have used a panel raising bit to dress up simple 2 x 4 P.T. top rails. The profile began a few inches from each end simply because the router base hits the post. (You'll have a similar limitation with a round-over bit.) That detail alone really gave it a "custom made" look. I've taken it a step further by running a 3/4" round over on the posts, but only between the two rails; leaving the top and bottom of the post square. It's not exactly a turned post, but it sure looks a lot better than a stock 4 x 4.

[museumguy]

Here's one with a 1/2"r that would do the cut in 1 setup. It does not have a guide bearing but could be used with a fence.
https://www.amanatool.com/products/route...-bits.html

[Steve N]

Substantial difference in Bullnose, and round over. If you want a true bull nose. You need to size the bit to the stock, or else you get shoulders.






If you are just trying to give a nice smooth rounded over look almost any round over bit will work.





On something as wide as a deck rail you can pretty easily run a hand held router along the top, and with an edge guide to hold the cutter out away from the work the appropriate distance do a pretty quick job. No matter which bit you end up using, set up cuts on some scrap are a good idea.

[BrentDH]

How about something like this
https://www.woodline.com/collections/bul...6055832833
I has a bearing in the center and an upside down round over on the top and a roundover on the bottom

It is called a  "double roundover with center bearing"

[Steve N]

How about something like this
https://www.woodline.com/collections/bul...6055832833
I has a bearing in the center and an upside down round over on the top and a roundover on the bottom

It is called a  "double roundover with center bearing"

Unknown is the thickness of the hand rail. If it is just a deck board on top of posts that bit is for a taller cut. If however it is a real railing and has some thickness it may be what the Doctor ordered, all would be dependent on size of the rail.

[jihhwood]

Yes, the round-over may be the best bet.

[jihhwood]

Thanks to all who responded.  Since the rail has already been installed, and since I'm yet to learn the thickness of the rail, my choices are still undecided and will almost certainly be limited.