Raymond McInnis -- Amateur Woodworker and Scholar of Woodworking HistoryRaymond McInnis -- Amateur Woodworker and Scholar of Woodworking History: Jigs for Creating Picture Frames with Compound Miters

under construction 1-18-07

This post shows designs for

a jig for cutting compound miters for constructing picture frames
a jig for gluing-up picture frames with compound-angled corners

I prefer to use a system for cutting the sides of picture frames that I devised myself for my radial arm saw. This system also works as well on a table saw.

My first photo is a picture of my Dad that I created out an old 4” X 5” box camera photo that I found in family memorabilia. The over-all dimensions of this frame are 19” w x 21” h, with the sides of the frame 3” w. The photo itself is standard 8” x 11” (I printed the photo with with my scanner and HP printer) but had the photo professionally matted. I also did a similar picture for my mother.

As well as barn wood, I have examples of frames constructed from molding that I have created with my shaper.

The frame in the photo below does not do justice to the frame’s 30˚ cant, a feature that gives considerable depth to the frame, depth that is missing when you simply glue up mitered frames at flat, 90˚ angles.

The photo of my Dad looks professional, largely, I think, because it is professionally matted. (For a joint funeral for my parents, I framed pictures of both my parents.) The racoon on the lower left is a Christmas gift for a friend of my wife. It's better at giving a sense of the depth of the frame that is obtained with the 30 degree slant on the frame's sides.

The depth the cant, 30 degrees, makes the frame, for me at least, quite striking. Photographed straight on, as for my Dad's (above) photo, this cant is hard to perceive.

Let me say that with more adept photography, the depth that the cant on the frame’s sides gives the picture an attractive appearance, certainly different than the rather heavy handed simple mitered corner look.

The material in the frame itself is old growth Douglas fir, taken from a 100-year old barn. Again, we live in the Puget Sound area of Washington State.

1. Cutting Compound Miters

The photo below, the four sides in prep for gluing, on the left, shows the angle or "cant" in the frame.

The photo on the right, directly below, shot from the side, gives you an idea of the angle/cant of the frame.

Experienced woodworkers will, immediately, understand that my technique allows you to overcome a difficulty inherent in working with "weathered barn wood." The charm of this media, the aged, "weathered" look, must be preserved, otherwise the appearance that you wish to achieve is ruined. Why? Once you cut weathered boards, a fresh cut is exposed. [will get a picture to illustrate soon]

The photo directly below is an "end" view, showing for the jig (1) the 30 degree angle, (2) T-track (for precisely cutting lengths of frame sides. and (3) aluminum "angle iron", for a precise cutting of the frame's sides.

[more description of T-track and related matters coming]

Note on photo on the right that along the lower edge toward the side of the jig, toward the viewer, is an aluminum angle iron. (See also above, end view of jig, where angle iron is easily viewable.) One side of the angle iron is attached to the jig itelf, while the second side of the angle iron etends upward and holds the stock, on one side or another, at a uniform position while the miter is cut.

In creating a frame, I first cut the rabbets. Making the square rabbet.

Again, my saw blade is set at 30 degrees. I place the fence to the right of the blade, just far enough that I able to place the kerf line exactly on the corner of the weathered board (check the blade's location in both left and right photos below). For the next cut (no picture yet), I move the fence over to the right, lay the board on its side, so that the cut cleanly removes the material and leaves a square rabbet, as illustrated in photo directly above, on right.

The photos above show the jigs that I created for the cutting on a radial arm set-up the compound miters for the frame’s sides . ( I can also show how it could be done on a table-saw, or of course my Hitachi compound miter saw. On the Hitachi, the jig wouldn’t be required, but the cutting operation would involve other complications, I think. )

photo from outfeed side of table saw

My jigs let woodworkers who lack the compound miter saw to easily make three dimensional frames with compound miters on the tablesaw. [will have more pictures and description soon.]

In the photo above is illustrated a downside of using weathereed barnwood. Every cut exposes wood that is not weathered. To avoid exposing these cuts, I cut the picture frames sides so that these exposed areas are always on the inside of the frame, "inside" in the sense that when the four sides are glued up, the cuts are located where the picture is placed in the frame.

Setting the saw blade at 30 degrees, I make two cuts, that form a "square rabbet". (See photo below, on right.) This square rabbet is cut so that the exposed, "fresh" wood is all eliminated, with the weathered frame sitting next to the matte, between the frame and the picture. For an example, look closely at the framed photo of my father, at the top, and focus on where the frame meets the matte.

2. Clamping System

The clamping system I use is from lee valley, but the clamps look very similar to WS catalog no 139-745. What I did not see in your catalog was the “ring”, important for holding the four clamps when the frames are glued up.

These photos, above, on the right, and below, show several features about this system: Use of biscuits for better glue up on compound angles at corners. Specially created clamps for holding angled corners securely, with surfaces tightly held together by metal “clips”, while glue sets.

The photo above below shows the final clamping set up. I pondered this problem (i.e., how to glue corners with compound angles) for many years, and, when I saw this clamping system in the Lee Valley catalog, finally settled on this solution. If there’s a “secret’, it is the clamps that I have created, which during glue up, with the aid of the metal “clips”, hold the surfaces of the compound angles tightly together, very important if the glue up is expected to last.

[needs editing] For the glue-up, the corner frames that I made have metal “cleats” that, corner by corner, apply pressure uniformly. (I bought the clamping system at lee valley store in coquitlam.) I was surprised myself at how efficient this clamp is. The clamping set-up itself I bought at lee valley. Before I thought of this solution, for glue-up, I used a brad nailer to hold one corner at a time, not a satisfactory way to go.

As the photo below shows, the picture frame clamps are simple. I made mine out of scrap wood and sheet metal. I think that equally effective clumps can be constructed out of plastic. If there is a downside, it is that the angle (in this photo, the bent metal “clip”) that helps secure good surface bonding is “fixed”. In this case the angle is 30˚. How make this clamp with an adjustable angle has, so far, eluded me. More important, is an adjustment mechanism needed? Most frames will be satisfactorily glued up with 30˚ cants. If other angles are desirable, plastic clamps with a variety of angles can be offered.

need better photo than above

The photo below shows the picture frame's corner at a different angle.

"Sizing" the frame to the matte. [need details here about difficulty of measuring appropiate size of frame's rabbet.]