New Guy Wants to Route Some 2x8 Handrails

[LCHIEN]

Thank you Lchien for your images.
Yes, a "round-over" is what I wanted.
When the weather warms up in 3-4 months I'll revisit this project.

A 2x8 is 1.5 inches wide
Basically what I understand you want is this profile for the rail


There's such a thing as a bullnose bit that will do this in one cut but its hard to use because it has no easy way to reference it's bearing. And it will be kind big at 3/4" radius. 1-1/2" diameter.

The best way and a useful bit to have when you are done will take two passes is a 3/4" radius roundover bit, makes a quarter-round.


basically with one pass you get a quarter round, two passes will get you a half round which is what you want. If the wood is reasonably well dimensioned you will get a nice half round/

I really would not do this with a router table... you'd be moving the wood which is big long, heavy piece. Hand held you'd be moving the router which in my opinion is much easier because is compact and light.

You kind of have to make a decision to route before assembly or after assembly.

• Before assembly can router the entire length but to make any corners look good you have to miter the corners where the rails meet.
• After assembly you can route around butt joined corners but the downside is you can't router to within a router diameter (3 inches) of an wall or post.

Also you have a choice of making two passes

• rail on edge and making two passes of either side (this will work better as the bearing can ride on the side of the board) But its hard because you don't have a very wide flat surface to run the router base plate against making it easy to tilt the router and make a less than perfect cut
• Rails lying flat, route one edge, flip over and route the opposite side. this is a little iffy because the bearing on the second cut does not have a good flat registration top sit on, but it works OK, the bearing sits on the edge of the crest of the curve. I think this is the way I would do it.

Another thing I would consider personally,
instead of a full 3/4" radius I would consider a 1/2" radius roundover giving 1/2 quarter round, 1/2" flat and 1/2" quarter round. Not quite so sharp to lean on for a railing top.
or even 3/8" - radius giving 3/8" QR, 3/4" flat and 3/8" QR. It's also easier to route eliminating some of the issues I raised above.



Before carving up big pieces of 2x8, you might want to practice on foot long pieces of 2x4.
You can choose whether you want to route the top edge or the side edge.
Also its going to take a bit of practice to set the bit height just right.
In the picture below, the bit depth or height makes the top curve just meet the top edge of the wood. Otherwise you just get a "bead" or a "step" not a smooth transition from the curve to the smooth/flat.



Loring

BTW, if you are buying bits and your router collet takes them, 1/2" shank is the way to go for this sized bits.

[Skeezix]

Thank you Lchien for your images.
Yes, a "round-over" is what I wanted.
When the weather warms up in 3-4 months I'll revisit this project.

[Black walnut]

To route the larger profiles, such as LCHIEN posted at bottom of his post you will need a router with speed control, for sure the router mounting kit, including the table to rear rail clamp, and a couple of profile bits. If you are using pine or hemlock/fir or spuce softwoods you should be able to get it done. Make a fence and take incremental bites. Use feather boards and push shoes. You can get close with a couple of roundovers and slight bevel custs on the tablesaw. If you can display the exact profile desired we can give you options to accomplish.

[jlhumbert]

Great answer! This forum has some of the best people.

[LCHIEN]

Glad to help. Routers can be very simple to very complex.
We can discuss table mount vs hand held router use and specifically mounting a router to a specific BT3 type table saw auxiliary router table. But first lets discover what you really want to route.
Do you just want to roundover the edges of a 2x8 railing on a deck? Or go for fancy stair railing molded handrails?

Getting the names right is the first level of understanding.
You say Circular bevel... is that we we normally call a roundover?



Router bit profiles all have names.
Roundovers come in various radius; they can also be used for beading For a 2x8 on vertical edge, like a deck railing, probably a 1/4", 3/8", 1/2", or 3/4" roundover on two edges will do.
A 1/4" roundover on both edges of a 2x8 on edge will leave a 1" wide flat; A 3/8" Roundover will leave a flat 3/4" wide, a 1/2" radius will leave a 1/2" wide. A 3/4" radius roundover on both sides of a 1-1/2" wide piece will leave zero width flat at the top, basically you have a 1-1/2" fully rounded over (180 degrees) top.
OTOH if the 2x8 is flat horizontal, a pretty wide hand rail, then the flat area will be wider and you might want to go as much as 3/4" radius.
All depends on how "soft" a corner you want to have on it. Construction 2x studs often come with a 1/8 to 3/16" roundover to start with.




Other common profiles


And then there are a bunch of specialty profiles for things like handrails, cabinets, frames, molding etc.

[Skeezix]

I bought my BT3 portable table saw from Sears around 20 years ago along with a new router. The plan was to attach it to the underside of the table saw. I wanted to route a circular bevel on some 2x8s and use them for handrails along my deck railings but I never got around to it and I don't know if this is feasible. The other possibility is to just run the router along a clamped-down 2x8 but I've never used the router before (and it's still in the sealed box that it came in when I bought it).
What say you??