Joinery for Wrapping Columns

Quick suggestions for corner joinery for wrapping columns with a Shaker frame. May 6, 2014

As part of a large lobby renovation I have to wrap many drywall columns on three or four sides with a 3x3 shaker frame using rift cut white oak. The columns are 88"tall and different sizes, varying from 24x24 to 22x36". I am planning on making the long corners with a miter joint and then precut ting the stiles oversize, pre-finishing everything and then assembling on site one column at a time using my pocket hole machine to connect rails and stiles on the opposing walls. Then Iíll be lamelloing the final stiles and using PL adhesive and 23guage nails to attach to columns.

Is the best and most accurate way to make the long 3x3x88 right angled rails using a lock miter bit in my router? I'd do not have a million clamps and was hoping to use this idea with stretch wrap or masking tape to hold till dry. I would appreciate any input here as most of my experience is with panel products. I will be ripping the material with my 10'slider with hold down clamps and then planing to exact size and thickness.

Forum Responses
(Solid Wood Machining Forum)
From contributor S:
The lock miter is an excellent joint for this purpose, have used it for similar on several occasions. If you can run it on a shaper you'll be happier with the result. It is a little fussy to get set, and a shaper with feeder with give you a more consistent result once you get it right. Be advised that the there is always a very slight overlap of one or the other at the apex of the joint that needs to be blended, which should be done before finishing. You will probably need clamps to bring it together - the way it comes off my shaper using an insert head is too tight to pull together with tape or similar.

From Contributor K:
If you can get by with a 1/8" radius on the long corners then forget about the lock miter and run a rabbet lengthwise on one edge of each panel, the rabbet can be the same depth as the panel thickness and leave about 1/8" at the visible edge thickness. This method is way easier than trying to miter full height panels, plus you can assemble them ahead of time for pre-finishing plus an 1/8" radius on the corners will help absorb imperfections and give you more glue area and easier to clamp-up as well.