Safety 101 – Demold and Mold Prep Safety

Welcome back to our three-part series on
keeping safe while working with carbon fiber & composites. In our
second installment we’ll be taking a look at Demold & Mold Prep

Demold and mold prep safety is much like
that of plycut and layup precautions. Keeping working areas clean, using
cut-resistant gloves, and wearing proper eye protection are all needed
to demold or strip cured laminates. During demold processes, it is not
the scissors or blade surfaces that could necessarily cause possible
damage to fingers or skin. A cured laminate, whether fiberglass, Kevlar,
or carbon fiber, is sharp along laminate edges. Thinner parts of the
laminate’s corners and cut ply edges all pose a risk of slicing through
skin and flesh. Fabrication with chopped strand mat fiberglass also
poses a risk as the fibers do not always carry uniformity; there are
possibilities that fiberglass fibers could be sticking straight up out
of the laminate. If the skin is not protected, it can go through the
skin with little to no force. Always wear proper eye protection as chips
and resin bleed out can be expected, and pieces can fly into the eyes.

the part is stripped or de-molded, de-flashing the part as soon as
possible is good practice. Using a right-angle sander and ~220 grit
sandpaper, sand away any sharp edges on the composite laminate; this
will make handling of the composite laminate much easier in the future.

safety is of the utmost importance in any process; however, part safety
of a cured laminate is also vital as some composite parts can be highly
fragile. Dropping some parts from only 3 feet has been known to scrap
laminates. Gravity tends to aid in dropping objects or chemicals onto
laminates. Wrapping parts completely or around edges with bubble wrap
will mitigate the chances of damage. The best practice is keeping parts
wrapped in bubble wrap when not used while being transported or stored.
Additional options include the application of a pool noodle or
polyethylene foam noodles around part edges.

a part is de-flashed and stored correctly in bubble wrap, mold
preparation will likely begin. Using a shop vac will help get a mold
cleaned of any loose resin and fabric that may have gotten loose on the
tool’s surface. Afterward, application of a cleaning agent and/or mold
release is needed. Hazards associated with mold releases are
corrosiveness and flammability. Though some mold releases are neither,
product safety must be adhered to per the product’s SDS. If mold
cleaner/release cleaner is flammable, proper storage at room temperature
in a well-ventilated area, along with keeping it away from any ignition
sources, is a must. It is best practice to keep flammable mold releases
in their own designated cabinet area, away from other flammable liquids
or ignition sources. Always refer to the product’s SDS for all
safety-related issues ensuring all proper care is taken. Chemically
protective gloves are best when applying any release agent.