Create a Fiberglass Mold From an Existing Part
Fiberglass is used to make anything from small toys to large industrial tanks. Many fiberglass applications such as boats or car parts are constructed using molds. To make a mold, the part that is being replicated gets covered in a mold release wax, fiberglass and other material. When the fiberglass hardens it is removed from the part and prepared for use as a mold.
Instructions
1. Apply a mold release wax to the surface of the part you will be replicating, using a foam applicator pad. Let the wax dry and wipe any excess off using a clean rag. Apply another thick coat of release wax and again clean any excess. This is very important in order to stop the fiberglass from bonding to the part.
2. Put on rubber gloves and add the methyl ethyl ketone peroxide (catalyst) to a small bucket of gel coat following the recommendations on the containers. Mix the catalyst into the gel coat using a stir stick. Add the gel coat to the spray gun.
3. Put on a respirator and apply the first layer of gel coat to the part in a heavy mist, spraying as consistently as possible. Let the first coat harden and apply a second heavier coat to the part. Let the second coat harden and add a third and final heavy coat to the part. Let the gel coat completely harden.
4. Cover the entire part in a layer of fiberglass mat, tearing the mat to the size needed. Do not overlap the seams in the mat. Use the first layer of mat for a pattern and tear four total layers of mat.
5. Add the methyl ethyl ketone peroxide to a small bucket of resin and mix them using a stir stick. Wet out the surface of the part using a four inch felt roller. Apply the first complete layer of mat and saturate it with resin using the felt roller. Use a paint brush to wet out any corners or crevices. Remove any air bubbles from underneath the mat and completely flatten the mat to the part using an air roller. Repeat this process for the remaining layers of mat and let the fiberglass harden.
6. Remove the fiberglass from the part using a small metal scraper. Insert the corner of the scraper between the part and the layer of gel coat and slowly work the scraper around the edge of the entire mold until the fiberglass releases.
