joining edges of an octagon?

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Forum topic by mzimmers posted 02-07-2014 07:57 PM 1637 views 0 times favorited 9 replies Add to Favorites Watch
View mzimmers's profile


160 posts in 3336 days

02-07-2014 07:57 PM

Topic tags/keywords: octagon joining

Hi, all -

I did a search, and found some threads related to this, but nothing quite what I was looking for. I want to build an octagon from 2×6 boards. I want the boards up on edge (so the octagon, lying down, would be 5.5” high). It doesn’t need to be super strong, but I’d like to improve upon just gluing miter joints.

I can’t figure out a way to use my dowelling jig for this, and I don’t have a biscuit joiner. Any creative suggestions?


-- M. Zimmers

9 replies so far

View brtech's profile


882 posts in 2343 days

#1 posted 02-07-2014 08:04 PM

How about pocket hole joints?

Not sure why your doweling jig wouldn’t work. As long as you orient it the right way, it should make the right holes. You could rig up a special purpose dowel jig just for this project pretty easily.

How big is each side? It it’s not too long, you could make a jig to hold the board to cut a spline on your table saw.
You could also build a simple jig to cut the spline groove with a router.

View bondogaposis's profile


3969 posts in 1771 days

#2 posted 02-07-2014 08:06 PM

How long are these boards? You could spline them using a table saw if they are short enough to handle on that machine. Other wise you might have build a jig for a router to cut the grooves.

-- Bondo Gaposis

View mzimmers's profile


160 posts in 3336 days

#3 posted 02-07-2014 08:09 PM

This is my dowelling jig:

Jessem Jig

There may be a way to do it, but I can’t come up with it.

Each side will be a little less than 2’. The spline idea is interesting; I could do that on my router table without a jig, I think.

-- M. Zimmers

View madts's profile


1662 posts in 1760 days

#4 posted 02-07-2014 08:12 PM

Take your boards and cut through at a 45 deg. angle half way through each board on one end only. This will give you you want . I can not draw it for you right now. So a 45 deg. vee on each board and put it together.

-- Thor and Odin are still the greatest of Gods.

View DKV's profile


3940 posts in 1924 days

#5 posted 02-07-2014 08:56 PM

The answer is in your user guide.

-- This is a Troll Free zone.

View mzimmers's profile


160 posts in 3336 days

#6 posted 02-07-2014 09:00 PM

Those boards aren’t cut at the right orientation for my project. The miter (bevel?) cuts will be perpendicular to those.

Just as an FYI for the readers, I’ve done the ones in the pic, and they work beautifully…IF you can consistently place each board in the jig, which isn’t as easy as it looks. I’m looking into ways to simplify that.

-- M. Zimmers

View mahdee's profile


3460 posts in 1188 days

#7 posted 02-07-2014 09:07 PM

You may be able to run the bottom of each end on the saw to make a cut in the middle. Then use a 1/8” strips (maybe from a darker/lighter wood) to join them together and clamp. You can run it twice for a thicker strips.


View mzimmers's profile


160 posts in 3336 days

#8 posted 02-07-2014 09:10 PM

brtech: somehow I missed your reply earlier. I was thinking of pocket holes, too. My only concern would be that, at the needed angles for an octagon, the screw are coming close to pulling on the grain, not against it. But…this still might be the easiest way to go.

-- M. Zimmers

View Jim Finn's profile

Jim Finn

2390 posts in 2342 days

#9 posted 02-07-2014 11:00 PM

How about , after gluing it up, drill holes through each joint and fill with a dowel and sand off flush.

-- "You may have your PHD but I have my GED and my DD 214"

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