|When assembling a solid wood panel
in a frame, such as a raised panel door on a cabinet, the panel must be free to
expand and contract with changes in humidity. It's not unusual for solid wood
panels to expand across the grain as much as 1/8" for every 12" of width.
That kind of movement can easily force apart the joints of a door.
So, obviously, you shouldn't glue a solid wood panel into the grooves or slots
of a door frame. Okay, but if the panel is free to move around, what keeps it
centered in the frame? The weight of the panel may pull it down, and if it's loose,
it might shift to the left and right.
PIN IN PLACE. One solution is to pin each panel in place with brads driven in
through the back of the door frame so it's less obvious. First, check that the
panel is centered side to side and top to bottom. After the panel is centered,
drive a single brad centered at the top and a single brad centered at the bottom
of each panel. By using one brad, the panel can expand and contract in both directions
from the center.
FOAM TAPE. A second method is to use foam rubber in the slots. Putting foam in
all four slots keeps the panel centered. When the panel expands, the foam compresses.
In some applications, such as exterior doors, the foam may have the added benefit
of blocking some air leakage. We've found that foam weather-stripping tape (with
an adhesive on one edge) works well for this. It's available at your local home
center in 1/4" widths (perfect for 1/4" slots). Build up layers in the
slot if necessary until the panel is snug in the frame. No one will ever know.
Go to Tip #9