How to Model With Fiberglass

Always wear protective gear when handling fiberglass mat and resin.

Different construction materials each have their own strengths and weaknesses. Fiberglass is a durable, lightweight material that combines the flexibility of liquid plastic with the strength and rigidity of glass fibers. While strong enough to construct boats and automobile parts, fiberglass is inexpensive and delicate enough to reinforce small craft projects and create free-standing models. It is not expensive or time-consuming to make fiberglass models; the basic kit has only three components: liquid resin, a liquid resin hardener and fiberglass matting.

Things You'll Need

• Safety goggles
• Rubber gloves
• Breathing mask
• Fiberglass
• Scissors
• Clay
• Knife
• Carving tools
• Mold release
• Liquid resin
• Liquid resin hardener
• 3 disposable cups
• Stirrer
• Brush
• Sandpaper
• Soap
• Water
• Bucket
• Gelcoat
• Paint

Instructions

1. Put on safety goggles, rubber gloves and a breathing mask.

2. Cut or tear the fiberglass mat into 4-by-4-inch squares. Cut several 2-by-2-inch squares for covering detailed areas.

3. Make a detailed model of the finished product out of clay using a craft knife and other carving tools. Wrap the model in plastic and air-dry it until the clay is leather-hard but not bone dry. Clay is leather-hard when it can be handled easily without marring the surface of the clay or upsetting the structure.

4. Spray the clay model with mold release.

5. Mix the liquid resin and hardener in the proportions prescribed by the manufacturer. Use disposable plastic cups to measure out the liquids. Combine the liquids in a third plastic cup and stir with a wooden craft stick.

6. Brush the resin mixture onto the surface of the model to moisten it.

7. Dip a square of fiberglass mat into the liquid so that it is submerged and soaked. Press it against the mold and use the tip of the brush to smooth the mat in place. Apply more liquid resin to the brush to saturate the mat so that it can be pushed into the crevices.

8. Repeat Step 7 to coat the entire piece with fiberglass squares.

9. Dry the model overnight. Modify the drying time according to the time table provided by the resin manufacturer.

10. Repeat Steps 5 through 10 to apply additional layers of fiberglass matting.

11. Remove the clay from the interior of the fiberglass model. Sand the fiberglass to achieve a smooth finish; pay close attention to stray fibers near the edge of the model. Rinse the piece in soapy water.

12. Paint the surface as desired. Brush on one to two coats of gelcoat to add a high-gloss finish and seal the piece.

References

• "The Fiberglass Repair and Construction Handbook"; Jack Wiley; 1988
• "Go to Google Books Home Advanced Book Search The Fiberglass Boat Repair Manual"; Allan H. Vaitses; 1988