Jigs for
Creating Picture
Frames with Compound Miters
under
construction 7-10-07 -
needs repair
This
post shows
designs for
1.
Cutting Compound Miters, using a jig for
cutting compound miters for constructing picture frames;
2. A clamping system, that is, 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
aged appearance that you wish to achieve in the frame is ruined. Why?
Once you cut
weathered boards, a fresh cut is exposed. [will get a picture to
illustrate soon]
In
creating
a frame, I first cut the "square" rabbets, i.e., the grooves, for inserting the
glass and matted picture.
After some experimenting, I found that by setting the "L"-angled
aluminum into a rabbet (groove) on the underside of the jig, at the
outer edge of the 30° angle, and having the "rabbets" in the
workpieces pre-cut (explained below), you cut each of the four
sides accurately. This rule is especially true when constructing
frames out of weathered boards, where the edges of barn borads are
rendered uneven by decades of rain, sleet, and wind.
Making
the
square rabbet/groove.
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.
 
Cutting the Sides of the Frame
In the
group four photos clustered below, the
photo on the left top is an "end" view of the jig,
showing: (1) the 30 ° 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. On the top right is the same jig, this time placed on
the right of my Delta radial arm saw. On the bottom, left and
right, are "before-and-after" photos that show how the sides
of the frames are precisely cut. (The secret is that, using the
combination of the T-track and the "L"-angled aluminum.)
 
My
jigs let woodworkers who
lack the compound miter saw to easily make three dimensional frames with compound miters on the
tablesaw.
In
the photo left 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 Woodworker Supply
catalog, no 139-745.
The photo
below shows 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.
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.]
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