Polyester Resin - Does it expire?

Joseph Humpston

Hello Guys! Hey, I've got a question about Polyester resin! How long is it's shelf life? I'm asking because earlier today, I mixed up some polyester resin for a suit of pepakura armor that I'm working on, and the resin is still a honey-like consistency! And I added the hardener as instructed!

Chris Ellerby

Resins can go bad over time as they are exposed to air, moisture, or extreme temperatures.  It's hard to say how long they can last, as that depends on environmental factors like humidity, temperature, etc.   If the resin ever freezes it will not set properly.

Polyester resin is known for having a fairly long shelf life. I can last years if unopened and stored properly.   Once the container is opened air (containing moisture) fills the empty space in the container, which can eventually lead to the resin going bad.  Some folks use gases like nitrogen to displace any air before sealing the container back up after use.

If you thoroughly mixed the proper quantities and they never cure it's possible the resin has gone bad, or is somehow contaminated.

I'd try mixing up a smaller batch of the same resin and see if it cures, just to rule out contamination.

/Chris

Joseph Humpston

Actually, it eventually did cure! It must have been that the ambient temperature was below the recommended, retarding the curing process. It did kind of have a dark-brown color to it though!

Chris Ellerby

Glad it cured for you!  Most resins cure slower at lower temperatures, and faster at higher temperatures.

/Chris

Joseph Humpston

Perhaps if I did this in the summertime, and started right after breakfast, I'd have an armor piece ready for it's next coat by lunch time!

Suat None

if produce company used our POSLEX when they manufacturer than shelf life going to long term without any bad semptom.. for more info pls visit http://izelkimya.com.tr/Urunler/273/doymamis-polyester-recineler/en