In order to produce a molding or laminate, a polyester resin must be "Cured". This is the name given to the over-all process of gelation and hardening. This is achieved either by the using a Catalyst and heating or at normal room temperature by using a Catalyst and Promoter.

Catalyst

Catalyst is a material added to resin to make it cure rapidly by oxidation with a accelerator as in polyester resin. This causes the heat which, in turn cures the resin.

Promoter

A Promoter is a material that enhances the action of a catalyst without actually having any catalytic value itself. Most rein manufacturers supply resin either with or without a promoter mixed in ("promoted or unpromoted"). All the promoted forms have a reasonably long shelf life.

"To lengthen the "Pot Life" of catalyzed polyester resin, fiberglass workers recommend the following practices:"

1. Mix only small quantities of resin and catalyst at a time.

2. Avoid high ambient (surrounding air) temperatures

3. Keep containers cool, such as by placing them in ice water.

WARNING

Polyester cure is an exothermic reaction; that is, the reaction releases heat which raises the temperature of materials in and around the reaction. The more rapid the reaction, the higher the temperature. That is why , for example, overcatalyzed resins, even in small quantities, can catch fire or explode, causing severe damage to life, limb, and surrounding property.

Suggested Safety Precautions

1. Allow ample ventilation.

2. Keep away from open flames and sparks.

3. If promoter is required, add carefully controlled amounts to the resin first, and then add catalyst.

4. Never mix just promoter and catalyst together. A violent explosion will result.