Tools
•
Safety glasses and power miter saw:
carbide saw blade with 80 teeth or
more recommended.
• Miter box
and hand saw: Limited angle
adjustment (not recommended for crown).
• Coping
saw: Only needed if you choose the
coping technique to install the moulding.
• Angle gage:
To create the correct miter, you must determine the wall corner
angle.
• Glue:
To adhere the miter joints, Royal Mouldings strongly
recommends
gluing all joints with PVC or “Pipe Cement.”
• Hammer &
nails or a pneumatic nail gun.
Other tools may include a tape measure, pencil,
C-clamp, putty and caulk.
Cutting
Use standard woodworking equipment for cutting.
If using a power miter saw, a carbide toothed blade is recommended.
Use any brand of spray furniture polish on saw blade as a lubricant
for easier cutting.
Wall Angles
It will also benefit you to measure the wall
angles on each corner. This will help you calculate the correct miter
angle. NOTE: It is not uncommon for corner angles in most homes to be
off as much as 3°. If you were installing 5” crown moulding the
3° difference would result in a 3/8” gap in the miter joint. To
help you calculate the proper angle Royal has an angle calculator
listed on their web site, www.royalmouldings.com.
•
Left and Right hand positioning: the
side of the trim you are cutting is as important as its position on
the saw table. The positions are illustrated above.
Vertical Miters
Use this technique for cutting baseboard, chair
rail, quarter round, and splice miters. Align trim back against
fence.
Inside corners:
A left hand inside corner is shown in the photo.
•
Step 1:
Place the trim on the saw table in the left hand vertical position
and rotate the angle gage “clock wise” to 45°, or the desired
angle setting, and make the cut.
•
Step
2: To cut the mating piece, simply
rotate the table angle gage to the opposite 45° or desired angle,
and place the next piece of trim on the saw table in the right hand
vertical position. Cut the trim.
Outside Corners:
A right hand outside corner is shown in the photo.
•
Step 1: To
complete this, place the trim on the saw table in the right hand
vertical position and rotate the angle gage “clock wise” to 45°,
or preferred angle setting, and make the cut.
•
Step 2: To
cut the mating piece simply rotate the table angle gage to the
opposite 45° or desired angle, and place the next piece of trim
on the saw table in the left hand vertical position.
Horizontal Miters
Use this technique for cutting window and door
casings. Align trim back on saw table.
•
Step 1:
A left hand miter is shown in the photo to the right. To get the
setup in the photo, adjust the saw table angle to the “clock wise”
45° or predetermined angle. Then lay the trim on the table in the
left hand horizontal position and proceed to cut.
•
Step 2:
To cut the mating piece simply rotate the table angle to the opposite
45° or preferred angle, and place the next piece of trim on the
saw table in the right hand horizontal position. After the cut is
made the miter joints are ready for assembling.
Compound Position Miters
Use this technique for cutting Crown moulding.
This is the most complicated of all the mitering cuts. Note: When
cutting Crown Mouldings in the compound position, remember “upside
down & backwards”. This term is used because the “TOP” of
the trim that is positioned against the ceiling after installation
rests on the saw table during the mitering process, and the “BACK”
of the trim that is placed against the wall, after installation, is
set against the fence during the cutting procedure.
Compound Inside Corner Miters
Left hand inside corner miter shown in
photo.
Step 1:
Place the top of the profile against the saw table and the back of
the profile against the fence in a left hand compound position. Then
adjust the table angle gage “clock wise” to 45° or calculated
angle, and cut.
Step 2:
Place the top of the profile against the saw table and the back of
the profile against the fence in a right hand compound position. Then
move the table angle gage the opposite calculated angle, and cut.
Compound Outside Corner Miters
Left hand outside corner miter shown in
photo.
•
Step 1:
The trim should lie on the saw table in a left hand compound
position. The saw is to be adjusted “counter clock-wise” to the
calculated angle before cutting.
•
Step 2:
Put the mating piece of trim on the saw in the right hand compound
position. Then move the table angle gage to the opposite calculated
angle and cut. The miter joint is ready to be put together.
Splice Miters
This technique is used to join mouldings
together in a linear run or when a wall is longer than the trim you
are installing. Most splice cuts are made in the vertical position.
In the photo below of a splice miter, note the only change made in
producing the joint is the right hand & left hand positions. The
saw angle should remain at the same 45° setting.
Return Miters
This technique is utilized when moulding ends
with an exposed, unfinished end that would require finishing “paint,
stain, etc.” This miter joint will create a finished edge.
•
Step 1:
To produce this miter, cut the trim as though you were turning an
outside corner (45° saw setting).
•
Step 2:
Rotate the saw to the opposite 45° and cut a short piece to mate
to the first cut. Glue miter joint together before attaching trim to
wall. See photo below.
Coping Joints
Coping is simply transferring the contour
“profile” of one piece of trim to the end of another piece of
trim, then cutting the profile line so that, when finished, the
second piece of trim will mate with the first with a nice joint.
•
Step 1:
Cut the first piece of trim to length and position it on the wall.
Use straight cuts, no angles.
•
Step 2:
To create the profile line, cut the second piece of moulding at a 45°
as though you were cutting an inside corner.
•
Step 3:
Following the profile line as a guide cut the trim
with a coping
saw.
•
Step 4:
The moulding should be ready for installation.
Nailing
Install No Rot®
mouldings using 6d and 8d galvanized nails and/or recommended
adhesives (see chart on this page). Place nails 12” on center.
Nails should be approximately 3⁄4”
from each edge. If nailing product at 40˚F or below, pre-drilling is
required. Pneumatic nailing is also recommended.
Gluing
Gluing Miter Joints
Royal Mouldings strongly recommend gluing all
miter joints on PVC or styrene mouldings using a quality instant glue
and/or PVC cement. It may seem unconventional, but the benefits out
weigh the inconvenience. When assembling splice and return miters try
gluing the mouldings together before installation. This will allow
you to fit the joints uninhibited, and fasten the trim to the wall as
one unit. Fitting these joints on the wall can be difficult and
possibly jeopardize the integrity of the miter joint.
Fastening Moulding to the Wall
Polystyrene and PVC trim can be nailed with
finishing nails and/or glued. Our recommendations for the nails are
paneling, finishing, or pneumatic finish nails. For the glue,
recommended products are PL Glues/PC —200, 300, 400/LIQUID NAILS
applied according to manufacturer’s directions. Glue alone is not
advised for crown mouldings.