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All Seasons Glass carries Acrylic (plexiglass)
and Polycarbonate (Lexan) in stock. We
carry acrylic and polycarbonate in several different thickness'
. Window repairs using acrylic meet requirements of the federal safety
glazing code for use in hazardous locations such as doors, storm doors and
windows next to a door. Plastics are used in many home decorating projects
and are easy to work with using standard woodworking tools.
Characteristics of the material
Acrylic Plastic
Half the weight of glass
Impact resistant
Unaffected by sun or salt spray
Temperature range of -30 to 160° F
for continuous service
Cleaning
Wash with mild soap or detergent, with plenty of lukewarm water,
dry with soft cloth or chamois.
Grease, oil or tar can be removed with hexane or kerosene. Solvent residue
should be removed by washing immediately.
Do Not Use window cleaning sprays, scouring compounds, acetone, gasoline,
benzene, carbon tetrachloride or lacquer thinner.
Masking
When working with the material, leave the paper masking film on
the sheet as long as possible. Except for intricate detail work you should
remove the masking only when your project is completed.
Working with acrylic plastic sheet
DO
Keep masking on as long as possible. Use metal cutting saw blades and drills
which are ground for acrylic sheet.
Make sure all tools are sharp.
Use water or drilling oil as a coolant when cutting sheets over 1/8" thick
or drilling sheets over 3/16" thick.
Wet the material before cleaning.
DON'T
Use saw blades with side-set teeth. Saw teeth ideally should be ground with 0°
of rake and be of uniform height and shape.
Cutting Acrylic Plastic Sheet
- Cutting with a knife or scriber
- Acrylic sheet up to 3/16" thick may be cut by a method
similar to that used to cut glass. Use a scribing knife, a metal scriber, an
awl, or a utility knife to score the sheet. Draw the scriber several times
(7 or 8 times for a 3/16" sheet) along a straight edge held firmly in
place. Then clamp the sheet or hold it rigidly under a straight edge with
the scribe mark hanging just over the edge of a table. Apply a sharp
downward pressure to break the sheet along the scribe line. Scrape the edges
to smooth any sharp corners. This method is not recommended for long breaks
or thick material.
- Cutting with power saws
- Special blades are available to cut acrylic. Otherwise use
blades designed to cut aluminum or copper. Teeth should be fine, of the same
height, evenly spaced, with little or no set.
- Table and circular saws
- Use hollow ground high speed blades with no set and at
least 5 teeth per inch. Carbide tipped blades with a triple chip tooth will
give the smoothest cuts. Set the blade height about 1/8" above the
height of the material. This will reduce edge chipping.
When using a hand held circular saw, clamp the sheet to
the work surface and use a length of 1x3 wood to distribute the clamping
pressure and act as a guide for the saw.
Feed the work slowly and smoothly. Lubricate the blade
with soap or beeswax to minimize gumming from the masking adhesive. Be sure
the saw is up to full speed before beginning the cut. Water cooling the
blade is suggested for thicknesses over 1/4", especially if edge
cementing will be performed.
- Saber saws
- Use metal or plastic cutting blades. The blades you use to
cut acrylic should never be used for any other material. Cut at high speed
and be sure the saw is at full speed before beginning the cut.
- Hand saws
- Good results are possible, but very difficult. Be sure the
acrylic is clamped to prevent flexing. Flexing at the cut may cause
cracking.
- Routers and shapers
- Use single fluted bits for inside circle routing and double
fluted bits for edge routing. At the high speeds at which routers operate it
is critical to avoid all vibration. Even small vibrations can cause crazing
and fractures during routing.
Drilling
For best results, use drill bits designed specifically for
acrylic.
Regular twist drills can be used, but need modification to
keep the blade from grabbing and fracturing the plastic. Modify the bit by
grinding small flats onto both cutting edges, so the bit cuts with a scraping
action. If the drill is correctly sharpened and operated at the correct speed,
two continuous spiral ribbons will emerge from the hole.
Finishing Acrylic Plastic
- Scraping
- The first step in getting a finished edge is scraping. The
back of a hacksaw blade is perfect for scraping. Simply draw the corner of
the square edge of the blade along the edge of the acrylic.
- Filing
- A 10 to 12 inch smooth cut file is recommended for filing
edges and removing tool marks. File only in one direction. Keep the teeth
flat on the surface, but let the file slide at an angle to avoid putting
grooves in the work.
- Sanding
- If necessary, start with 120 grit sandpaper, used dry. Then
switch to a 220 grit paper, dry. Finish with a 400 grit wet/dry paper, used
wet. Grits as fine as 600 may be used. Always use a wooden or rubber sanding
block.
When removing scratches be sure to sand an area larger
than the scratch. Sand with a circular motion, and use a light touch and
plenty of water with wet/dry papers.
Almost any commercial power sander can be used with
acrylic. Use light pressure and slower speeds.
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- Polishing
- Final polishing will give acrylic a high luster.
Power-driven buffing tools are recommended without exception. Buffing wheels
are available as attachments for electric drills.
A good buffing wheel for acrylic consists of layers of
3/16" carbonized felt, or layers of unbleached muslin laid together to
form a wheel. Solidly stitched wheels should be avoided.
The wheel should reach a surface speed of at least 1200
feet per minute. Speeds of up to 4000 feet per minute are useful for
acrylic.
Acrylic should be polished using a commercial buffing
compound of the type used for silver or brass, or you can use a non-
silicone car polish that has no cleaning solvents in it.
First, however, tallow should be applied to the wheel as a
base for the buffing compound. Just touch the tallow stick to the spinning
wheel, and then quickly apply the buffing compound.
To polish, move the piece back and forth across the
buffing wheel. Be careful not to apply too much pressure. Keep the work
constantly moving to prevent heat buildup.
Never begin polishing at the edge of the sheet. The wheel
could easily catch the top edge and throw the piece across the room or at
you.
Forming Acrylic Plastic
Acrylic can be heated to make it pliable. It will become rigid
again when it cools. Never heat acrylic in a kitchen oven. Explosive fumes can
accumulate inside the oven, and ignite.
A strip heater is the best tool to form acrylic. This tool
will only form straight line bends. Buy one from your acrylic dealer. The strip
heater will heat just the area to be formed.
Heat the sheet until it begins to sag at the bend line. The
bend should be made away from the side exposed to the heating element. Sheet
thicker than 3/16" should be heated on both sides for a proper bend. Use
forming jigs or clamps for best results, and wear heavy cotton gloves when
handling heated acrylic.
Forming other than straight line bends will generally require
specialized equipment and jigs.
Joining Acrylic Plastic
Solvent cement is recommended for joining acrylic. There are two
techniques for solvent cementing, capillary and dip or soak methods.
- Capillary cementing
- This is the most popular method for joining acrylic.
However, this method will not work at all unless the parts to be joined fit
together PERFECTLY.
Make sure the parts fit properly. Then join them with
masking tape or clamp them in a form to hold them firmly in place. It is
important that the joint be in a horizontal plane, or the cement will run
out of the joint.
Apply the cement carefully along the entire joint. Apply
from the inside of a box-corner joint, and on both sides of a flat joint. A
needle-nosed applicator bottle is recommended. The thin cement will flow
into the joint through capillary action and form a strong bond. Maximum bond
strength will not be reached for 24 to 48 hours.
POLYCARBONATE
(MakrolonŽ, LexanŽ)
Polycarbonate is a tough, dimensionally stable, transparent thermoplastic
that has many applications which demand high performance properties. This
versatile thermoplastic maintains its properties over a wide range of
temperatures, from -40"F to 280"F. It is available in three types:
machine grade; window and glass-filled. It is the highest impact of any
Thermoplastic, transparent up to 2" in special grades, outstanding
dimensional and thermal stability, exceptional machinability, stain resistant
and non-toxic with low water absorption.
Machine Grade is relatively stress free to permit the most demanding
machining. It is also available in glass-filled. This polycarbonate is perfect
for high performance uses in tough applications over a broad temperature range.
Window Grade is optically clear, providing total luminous transmittance and
very low haze factor. The high impact strength makes it resistant to repeated
blows, shattering and spalling.
Glass Filled
Glass-reinforced polycarbonate is finding principal applications in designs
where metals, particularly die-cast aluminum and zinc, are commonly used. The
coefficient of thermal expansion is reduced by nearly 75%, thus equaling that of
some metals. While glass-reinforced has less impact strength than standard
grades, it is still tougher and more impact resistant than most other plastics
and die cast aluminum.
ADVANTAGES TO POLYCARBONATE
Impact strength
Unnotched polycarbonate is virtually unbreakable, making it extremely safe
in areas where parts may be exposed to impact. When exposed to repeated heavy
blow, the material tends to cold form rather than shatter.
Electrical
Polycarbonate is excellent for electrical applications, because of its high
dielectric strength and high volume resistivity which decreases only slightly as
temperature or humidity is increased.
Machinability
Parts can be easily machined from standard metal working tools. No special
tools are needed, and finished parts can be polished to a high gloss. Water or
water-soluble cutting oils should be used when machining polycarbonate, since
some standard cutting oils will attack the material. Polycarbonate can be
machined on standard metalworking or woodworking equipment. Its unique
properties permit it to be machined without chipping, splitting, or breaking.
Bonding
Polycarbonate can be mechanically bonded by standard methods. It can also be
cemented by using a solvent such as methylene chloride or adhesives such as
epoxy, urethane and silicone. Polycarbonate and also be ultrasonically or
vibrationally welded.
Removing paint or other materials
Fresh paint may be removed by rubbing lightly with a cleaning material such as
isopropyl alcohol, or VM-P grade naptha. Then the sheet should be washed
immediately with a mild soap or detergent in warm water, and rinsed thoroughly
with clean water. Grease and glazing compound may similarly be removed from the
surface with the above mentioned cleaning materials. Weathered paint may be
lifted off the sheet with masking tape. Razor blades or other sharp scraping
tools should never be used.
MORE ADVANTAGES TO POLYCARBONATE
Formability
Standard polycarbonate sheet is not heat formable; however, formable sheet
is available on a custom basis. Standard Lexan polycarbonate sheet can be heat
formed with proper pre-drying. Lexan sheets up to 114" may also be cold
formed under special conditions.
Cleaning
Kleenmaster Brillianize may be used. (Also see Novus) Products such as abrasive
or highly akaline cleaners, acetone, carbon tetrachloride, benzene or leaded
gasoline should not be used, and the sheet should not be cleaned in hot sun or
at high temperatures.
Scratch Removal
Craftics 20/20 Plasti-Polish Scratch Remover is often all that is required to
subdue hairline scratches and minor abrasions. Any polish, however, should be
tested first on a sample area of the polycarbonate sheet.
Decorating
Polycarbonate products will accept painting, printing, or vacuum metalizing as
decorating methods.
UV Stabilization
Natural and Black Machine grade and Window grade are UV stabilized.
Polycarbonate rod, machine grade, is not UV stabilized, but is available on
custom quotation.
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