How can I cut railed horizontal fence boards for a 50-degree angle?

Question

I am installing a horizontal WPC wood composite fence that uses aluminum posts with embedded rails. The tongued boards measure 0.6" x 6" x 72". I need to make one 50-degree turn in the fence. The fence manufacturer sent me this diagram:

What's the easiest way to cut these angles on the end of 13 boards? I have a 12" compound miter saw and I could probably get access to a table saw, but is there some kind of jig that I could use or make or anything else that might be the easiest way to cut these boards?

Answer 1

screw a fillet piece to the end of the boards

the result will be much stronger than trying to cut the board to fit in the post, and will look better.

Answer 2

The main cut can be mitered with the compound miter saw, possibly on either of its axes (hold board vertical and cut straight down, or lay board on its face horizontally and cut on the compound axis). Could also be easily done with a table saw.

Then you're left needing to create the notch. A router seems like a good way to go. Here are some options:

1. A rabbet bit could be used if the router is pushed across the face of the board. You'd need some tapered jig or shim to hold the router base up at an angle relative to the face of the board. If the base of the router is wide, or the angle between router and board is large, or the bit doesn't protrude far enough below the router base, this arrangement may fail.
2. A dado bit could be used if the router is pushed across the end of the board. It'll be hard to balance the router on that narrow end face though; some kind of jig to give it better support would help. Also a dado bit has no guide bearing; you'll have to be really good free-hand or add a guide fence to your jig.
3. (maybe 2.5) Use a dado bit as in 2, but use a router table. Fix a guide fence to the router table; make a wedge to support the workpiece at the correct angle; push the workpiece across the dado bit.

That last one could be accomplished similarly with a table saw with or without a dado blade, but to me that arrangement seems a little sketchy. I'd feel safer doing it with a router.

Answer 3

The end cut is easy on the compound miter saw.

For the notch, my first thought was a router on an angled sled as Greg Hill suggested. However, thinking about it some more, I'd suggest a dado blade in the (borrowed) table saw.

Use a crosscut sled to hold the fence rail (loads of examples on YouTube about building and using crosscut sleds, from simple to extremely fancy) then run it past the dado head tilted 5°. Most table saws can only tilt to 45°, so you'll need to cut the reciprocal angle by running the rail on the other side of the blade. Your table saw owning friend should be able to help you with the proper setup here.

A crosscut sled will hold the rail at a 90° angle to the blade with no issue. You may will need to add a hold down clamp or two, something like this:

^{Image courtesy of Harbor Freight. Generally satisfied customer, no other affiliation.}

One or two of those will clamp and release very quickly, yet hold a long fence rail very securely for the cut. (Note, this item is all of $5 at HF, so it's not a huge investment. They're available at other retailers, too.)

This has two distinct advantages over the router table sled.

• Even if you have to build a crosscut sled (and your friend may already have one), your jig build time should be much less than building a sled for the router. Especially since you need to make an angled sled (which will involve, most likely, ripping lumber at a 5° angle and borrowing the table saw anyway).

• Once you've got the saw set up (blade angle, cut depth, distance from the fence), you'll be able to make all the cuts in no time.

  With the router sled, you can set up a fence of sorts to position it at the right distance from the end of the rail, but it would take more time (as I'm envisioning it) to set up the sled, position it, clamp it down and put the router into it.

• The table saw will easily make the cut in one pass. The router (as noted in the comments on Greg's answer) will most likely need to make a couple of passes. It's often difficult and potentially unsafe to make cuts that big with a router. Having to either make passes at half-depth on all boards, reset the router to full-depth and do them again, or make two passes on each board, resetting the router depth will be more time consuming.