West System Epoxy - Tech question

[abl1111]

I have stored some West System Epoxy for several years. Works great still.

The smaller container, the catalyst is RED in color. I don't remember if this is the color it was when new...

Is this the way it is new, or did it change color over time ?

[aldo]

It does change color over time and it is okay to use. Doesn't change it's strength.

[Blue_Heron]

I've used old epoxy after the catalyst turned red. It worked fine. Seemed a little easier to sand so it may not be as hard as when fresh. Personally wouldn't use it for a critical structural use, but wouldn't hesitate to use it for nonstructural parts or patches.
Dave

[aldo]

From the West System user manual " Hardeners may darken with age, but the physical properties are not affected by color..."

[abl1111]

Thank you, gentlemen !