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
  • Brushes/rollers/spreaders
  • 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.

-Apply immediately

-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 or an art than a science***

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