Polyester Laminating Resin Guide
Polyester laminating resin, also known as fiberglass resin, is the most commonly used resin in the industry. It is used in a wide variety of projects including boats, car bodies, kayaks, surfboards, patio decks and aircraft. It is affordable and easy to use. It has a quick cure and adds dimensional stability. Polyester resin requires MEKP hardener. Needed Supplies (this will vary depending on your project):
- MEKP (methyl ethyl ketone peroxide) is required
- Safety clothing- gloves, mask, eye protection
- Mixing cups
- Stir sticks or drill head
- Cleaning supplies- rags, acetone etc.
-Work in a well-ventilated area. Polyester resin gives off strong fumes
-Wear proper safety clothing including gloves and a face mask
-Make sure the resin, room and the surface you are working on are heated up to room temperature. The ideal temperature to work in is between 70-75 degrees.
-Use mixing cups to measure the resin
-MEKP can be used between 1% and 2% by weight but we recommend 1.25% to 1.75% depending on how long of a pot life and working time is desired. The more MEKP that is used, the shorter the pot life/ working time will be. The less MEKP that is used, the more pot life/ working time there will be.
-Mix thoroughly for at least one minute.
-Depending on your project, you can use brushes, rollers, spreaders or squeegees to apply the resin.
-Work in smaller batches
-Gel time will vary from around 10-20 minutes depending on how much MEKP hardener was added and the room temperature
-Polyester resin has a shelf life of around 6 months. Store in a cool dry space.
-Polyester resin without wax cures with a surface tack which helps multiple layers to adhere to each other. It also does not require sanding between layers. A finish resin contains wax that creates a hard tack free finish. If you do not want to purchase a finish resin you can add surface seal to the laminating resin for the final layer of your project.
-Polyester resin can be used on wood, metal and fiberglass. Do not use polyester resin on styrofoam as it will melt it.
-Do not add too much MEKP. If too much hardener is added, the finished product can be prone to fractures or resin will become rubbery in the mixing cup.
-If you do not add enough MEKP, your laminate may never cure.
***Always try out a small test batch first. Working with resin is more of an art than a science***