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Raised
Panel Door Tools and Techniques
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Part II - An Arched-Top
Raised Panel Door in Ten Steps
Below,
we'll go through the steps involved in making an arched-top
raised panel door. As you'll see, with the right tools and
equipment, the process is actually fairly simple and
straightforward. Woodworkers with intermediate skills and
some experience using a router table will have no trouble
mastering the techniques in a short time.
Step 1 -
Selecting and Preparing the Stock
The first step in making a frame and panel door is to select
and prepare the stock. This step is important. The
squareness and flatness of the finished door will depend in
a large part on the quality of the stock selected. In
selecting the stock for our door, we sorted through several
pieces of cherry hardwood before selecting a few pieces that
appeared flat, free of twists and relatively
straight-grained.
For a more in-depth
look at frame and panel construction, we recommend
Bill Hylton's Frame
and Panel Magic
It's a good idea to prepare
and mill more stock than you are actually planning to use.
You'll usually want to do a few test cuts along the way, and
there is always the possibility of making a mistake.
Weighed against the time it would take to back up and repeat
a step after making a mistake, cutting a few extra pieces of
stock is worth the added effort.
After selecting the stock,
cut the stiles and bottom rail to a width (2-1/4'' is fairly
common). Next, cut the blank for the arched top rail. You'll
want to cut the blank 1/16'' wider than its finished width
to leave yourself a little room for final trimming. Use the
rail template from the
Arched Door Template Set as a guide when determining how
wide the blank should be.
At this point, you can cut
the stiles to a length of 1 or 2 inches longer than their
finished size - you'll trim them to their exact length later
on. Prepare the stock for the panel at this point also. You
may also need to edge glue two or more pieces of stock
together to come up with a piece that's both wide enough for
the panel and as flat as possible.
Don't like math?
The
Woodshop Calculator will do it for you. This
affordable software system does all of the
calculations necessary for frame and panel door
construction.
Note:
If you are planning to trim the edges of the finished
door, or finish them with a
Custom Door Edge Router Bit, you'll want to add
1/16'' or so to the width of the stiles and rails.
Remember also that you will be trimming this off when
you finish assembling the door. You need to leave the
extra width out of your calculations for the length of
the rails.
Step 2 -
Calculating the Length of the Rails
Once you have the bottom
rail and the blank for the top rail cut to width, you can
begin preparing for the cope cut by calculating the length
of the rails. This can be a little tricky. To determine
the length of the rails, you need to subtract the
combined width of the two stiles from the overall width of
the door, and then add back in the depth of the panel groove
(to account for the overlap between the panel groove and the
coped end of the rail). Here is a formula for calculating
the length of the rails:
|
Rail Length =
|
| |
Door Width |
| - |
Width of
stiles x 2 |
| + |
Panel Groove
Depth x 2 |
|
Most stile and rail bits
(including the
Rockler Stile and Rail Bit Set used here) cut a 3/8''
deep panel groove. Using the Rockler bit set, for a
door to be 18'' wide when it's finished, with a 2-1/4''
finished stile width, the rail length should be:
|
Rail
Length =
|
| |
18'' |
| - |
4-1/2'' |
| + |
3/4'' |
|
| |
14-1/4'' |
Step 3 -
Setting the Coping Bit Height
With the bottom rail and the
blank for the arched top rail cut to length, you're ready to
set up to cope the ends of the rails. Setting the coping bit
to the correct height is important. The match between the
height settings of the stile and rail bits will determine
whether the stiles and rails meet flush with one another.
The
Rockler
Router Bit Set-Up Jig makes setting the bit height easy.
The jig has the sticking profile cut at optimum height into
one of its sides, and the matching cope cut into the other.
You just raise the bit until it fits into the jigs cope
profile and the bit is set at the optimum height. When it
comes time to cut the sticking profile, simply repeat the
procedure using the sticking profile on the other side of
the jig.
Step 4 -
Cutting the Copes
Getting a cope cut that's
square and as close to perfectly level as possible is
crucial. The cut has to be square if the parts of the frame
are to fit together correctly, and it needs to be level
(consistent in height over the length of the cut) to insure
that the door will lay flat and that the stiles and rails
will meet flush with one another.
To
make coping the rails easier, and to insure our coping
accuracy, we used the Rockler
Rail Coping Jig. The jig's backer is set to make a
perfectly square cut. The jig is also designed to keep the
end of the rail level with the coping bit during the cut.
Just butt both the edge of the jig and the end of the rail
up against the fence and clamp the rail in against the
hardwood backer. The backer (included with the jig) prevents
"tearout" that would otherwise happen when the rail exits
the cut. When we have one coped, we just flip the rail
around and do the other side.
Note:
When making the second cope cut on each rail, be sure to
turn the rail around end for end - don't flip it over. It is
surprisingly easy to forget that both cope cuts have to be
made with the same side of the rail facing up.
Step
5 - Cutting the Sticking Profile
Next, set the height of the
sticking profile bit - again, we recommend using the Rockler
Router Bit Set-Up Jig. For the straight-line profile
cuts on the stiles and bottom rail, position the fence so
that the profile cut will end up on the very edge of the
stock. Use a straightedge to line the stile bit's pilot
bearing up with the surface of the fence. Since the sticking
profile and groove are cut along the length of the grain,
tearout at the end of the cut is not a concern. Just feed
the stock at a moderate rate, and make sure that it's
kept in firm contact with the fence and the surface of the
router table over the entire length of the cut.
Once you have the fence set
up, run all of the straight edges - the two stiles and the
bottom rail. While you're at it, put a profile on a couple
of extra pieces. You'll use them in the next step.
Step
6 - Cutting and Milling the Arched Top Rail
Now you're ready to cut the
arch in the top rail. Here's a trick that will make the
process safer and much easier: Fit "temporary stiles"
(short pieces of stock milled with the sticking profile)
into the end of the blank and clamp the three pieces
together with a lightweight bar clamp. The purpose of the
temporary stiles is to provide a place to start the profile
cut.
Skipping this part means
that you would have to start the cut on the very tip of the
arch and run the risk of the bit catching hold of the corner
of the rail, which would at the very least damage the corner
or coped end of the rail. Apart from being potentially
dangerous, having this happen is an unpleasant surprise that
turns a perfectly good arched rail into a piece of scrap.
The temporary stiles also protect the fragile end of the
arch from breaking off when you exit the sticking
profile cut.
With the three pieces
clamped together, mark off the arc, using the
rail template that comes with the
Arched Door Template Set (be sure to choose the rail
template that has the correct width range for the door you
are making) and rough-cut the shape 1/16'' oversized with a
band saw. To make the sticking cut in the arched top rail,
attach the pattern to the blank with double-sided tape.
The template will guide the router bit's pilot bearing, so
you want to make sure that it's secure and won't slip during
the cut.
Note:
With the temporary stiles clamped securely in place, and the
pattern attached securely to the top of the rail, cutting
the top rail sticking profile is usually a smooth procedure,
but also requires extra care. Starting a router cut in the
middle of an edge can cause the bit to climb (pull the stock
in the opposite direction from the intended cut
direction). Be sure to ease into the cut slowly, hold on to
the rail/temporary stile firmly, and keep your fingers well
away from the path of the bit. If you have limited
experience using a router and router table, making a few
test cuts on a piece of scrap to get the feel of the
procedure would be a good idea.
Step 7 -
Cutting the Panel to Width
The first question to ask
yourself when figuring the width of a solid wood panel is
"how's the weather?" In other words, you'll need to factor
in how the humidity level in your shop while you are making
the panel is affecting the stock. If you are working in a
northern climate in the dead of winter in an un-humidified
shop, the wood you are about to make into a panel is
probably about as dry as it's likely to get. In that case,
you'll need to reduce the width of the panel by 1/8'' for
every 12'' of width to allow for expansion when the humidity
is high. The width of a fully moisture-expanded
panel should still be 1/16'' less than the length of the
door's rails to provide a little assembly clearance.
The formula for the width
of a door panel is:
|
Panel Width =
|
| |
Rail Length (from
tip to tip) |
| - |
Expansion
Allowance |
| - |
1/16'' Assembly
Clearance |
|
Note:
If you're planning to use
Space Balls to keep the panel centered and to
forestall any possibility of "panel rattle," increase
the assembly clearance for both the width and height of
the panel from 1/16'' to 1/4'' total (1/8'' for each
side).
It was a sultry summer day
when we cut the parts for our door, so we assumed that our
stock was about as loaded up with moisture as it was likely
to get. We just subtracted 1/16'' from the total length of
our rails to find the width of the panel.
Step 8 -
Cutting the Panel to Height
Since wood expands far more
across the grain than lengthwise along the grain, the height
of the panel can be made just 1/16'' smaller (for assembly
clearance) than the actual dimension of the available space
inside the panel groove. If you are making an arched top
door, the width of the top rail, of course, varies. Using
the width of the rail at its narrowest point (midpoint
between the two ends) will allow you to determine the height
of the panel at its tallest point:
|
Panel Height =
|
| |
Door Height |
| - |
Top Rail Width (at
the center) |
| - |
Bottom Rail Width |
| |
| - |
1/16'' Assembly
Clearance |
| + |
Panel Groove Depth
x 2 |
|
When
you've calculated the height of the panel at its tallest
point, and the panel blank is cut to its finished width, you
are ready to mark and cut the curved top of the panel. Use
the panel template to mark off the shape of the arched top
of the panel. Be sure that the template is square with the
edge of the panel, and that it's placed so that you'll end
up - after rough-cutting the arch - with a piece that's
1/4'' or so longer than the finished panel height you've
calculated.
Note:
Be sure to use the panel template from the
Arched Door Template Set that corresponds to
the rail template you used in Step 6!
The rail templates are clearly marked to help make this
easy.
When rough-cutting the
panel, keep the band saw's blade well on the scrap side of
the line - you'll use the line again when you attach the
template to the panel in order to trim it smooth with a
flush trim router bit. When you have the arch trimmed
smooth, simply measure down the panel along the center line
from top to bottom to mark off the panel height you've
calculated. Crosscut off the excess to finish sizing the
panel.
Step 9 -
Cutting the Panel Profile
With the panel cut to size, you're ready to profile the
panel with a
raised panel router bit. Having decided on a cove
profile for the edge of the panel, we cut our panel profile
with a
cove profile horizontal panel raising bit. The bit we
used was equipped with a "back cutter," meaning
that it makes a cut in the back of the panel as well as the
front. There are two advantages to using this type of bit:
Simply raising and lowering the height of the bit allows you
to quickly and easily place the raised field of the panel
anywhere you'd like in relation to the front surface of the
frame. The back cutter also insures that the panel edge will
be exactly the right thickness to fit snugly into the panel
groove.
We decided to have the
surface of our panel protrude up past the surface of the
frame by as much as possible, but we set the bit height so
that the back cutter would take off 1/32'' of material to
insure that the edge of the panel would be exactly the right
thickness for the panel groove.
To cut the panel profile,
set the raised panel bit at the desired height and use the
bit's pilot bearing to carefully guide the curved top of the
panel through the cut. Be sure to grip the panel firmly and
keep it pressed tight against the surface of the router
table at all times. Then, for a little added support while
cutting the straight sides of the panel, set the fence in
line with the panel bit's pilot bearing as you did with the
sticking profile bit in Step 5. Use the
fence as a guide while you cut the straight sides of the
panel, beginning with the bottom edge.
Step 10
- Assembly
Assembling the door is a fairly straightforward process, but
there are a few thing to watch out for. Most importantly,
the surface you're working on when gluing-up the door should
be as close to perfectly flat as possible. Here, we used
the
Bessy K-Body Clamp System, which is designed to help
keep parts flat and square during glue-ups.
We recommend cutting the
stiles to their exact finished length (plus any extra width
you've added to the rails for trimming) before
assembly. That allows you to take advantage of the clamp
system's K-P Blocks. The K-P blocks make it possible to
arrange clamps for four-sided clamping, and allowed us to
use the length-wise clamps to align the top and bottom ends
of the stiles with the top and bottom edges of the rails.
It's a good idea to
"dry-fit" the parts before applying the glue, just to make
sure that everything fits together correctly, and that you
have the procedure down. When you're satisfied with the fit
of all of the door's parts, apply a judicious amount of glue
to the ends of the rails and assemble the door. Gently clamp
the parts together (you don't need a lot of clamping
pressure - just look for a tight fit between the stiles and
rails). It is extremely important to press the door down
flat against the surface of the clamps while tightening them
down. When the clamps are tightened, check the door for
flatness with a straightedge or level. If the door is out of
flat, loosen the clamps, press the door down flat against
them and re-tighten them.
Finally,
wipe off any excess glue and check the squareness of the
door by measuring diagonally cross-corners in both
directions. If the rails have been cut and coped square, the
door should clamp up square almost "automatically." But it's
a good idea to check anyway.
If the cross-corner
measurements don't match, the door is out of square. Loosen
the clamps slightly and apply a clamp across the two
corners that have the longest corner-to-corner measuremen.
Slowly tighten the diagonal clamp while monitoring the
opposite corner-to-corner measurement. When the difference
between the two measurements is equalized, re-tighten the
clamps and check again for flatness.
Follow the glue
manufacturer's instructions for clamping time. After
unclamping the door, trim the edges of the door as needed,
or finish them with a Custom Door Edge Router Bit. In most
cases, you'll just need to give the door a light sanding
before finishing with a quality
wood finish.
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