Full Product Manual

35
Protective Coatings
Masking compounds are available that can be sprayed on the
Plexiglas
®
acrylic sheet and later peeled off. These are especially
useful when remasking formed parts.
The spray masking compounds should not have a harmful
chemical action on the Plexiglas
®
acrylic sheet. Some masking
compounds may be used indoors for periods as long as twelve
months. In general, no masking compound should be used on
parts that will be stored outdoors.
When using spray masking compounds, apply a coating at
least 3-5 mils thick. If the film is too thin, it may be difficult to
remove. The film should also be uniform and free from runs and
other imperfections.
To remove spray masking from Plexiglas
®
acrylic sheet, peel it
off or lift a corner of the film and blow a jet of compressed air
under it. If the film is hard to remove because it was applied too
thinly, apply a fresh coating of the masking compound, let it dry,
then remove it. In some cases, it might be necessary to apply
a layer of cheesecloth over the fresh spray coating and let it dry
before attempting removal. The cheesecloth reinforces the spray
coating and makes it easier to remove.
Remove protective spray masking coatings from Plexiglas
®
acrylic
sheet parts before the parts are annealed. Otherwise, optical
distortions may occur in areas where the thickness or surface of
the coating is irregular.
The manufacturers of the protective spray masking should
provide the precautions necessary for the safe usage of
their products.