Don't Blush

From my readings and experience, there is not much to worry about. I had some go red a couple years ago, never noticed any performance problems from it.

Darkening of the epoxy harder in time is quite normal.
You only have to be warned if it kristalises white; the Cycloalifatic Amine can react with moisture in the tin. See for instance the spoiled rests around the cap.

The epoxy itself doesn't deteriate so quickly. If you have solid sediment, you can simply warm it up to maximum 60 celcius and it's the old one again.

thanks guys!

agreed - if it's just red, it's fine. However, if it is both red and has a strong acidic odor, it's trash - it will cure albeit very very slowly and cures milky. I doubt the resulting strength is very good. The acidic odor is really pungent - you won't have any doubt if it's hit that stage if you are paying any attention at all.

Thanks Jake - i never heard that before.

so... if it eats your face off, it's probably gone bad?

I hadn't either but I experienced and tested with it first hand. I had bought a lot of epoxy for a large project a long time ago and this was some of those left overs. I've used this stuff for a long time with the amber colored with no problem. I noticed this time though, that it had a really sharp odor so, before using it, I mixed some up in a cup and let it cure. It was the fast setting 205 hardener that smelled so bad and I used it with some relatively new 105 resin. After properly dispensing and mixing, it took a little over two days (way too long) to cure to a hard finish in the mixing cup and it cured to a very unusual tan/milky color. I had newer stuff on hand and needless to say I didn't use the old stuff.

This is mentioned in the official west data for the combination 105 and 205:

Store at room temperature. Keep containers closed to prevent contamination. With proper storage, resin and hardeners should remain usable for many years. After a long storage, verify the metering ac cu racy of the pumps. Mix a small test batch to assure proper curing.
Over time, 105 Resin will thicken slightly and will therefore require extra care when mixing. Repeated freeze/thaw cycles during storage may cause crystallization of 105 Resin. Warm resin to 125°F and stir to dissolve crystals. Hardener may darken with age, but physical properties are not affected by color. Be aware of a possible color shift if very old and new hardener are used on the same project.

I was talking more about the pungent odor phase after the amber color. Amber color is no problem but if it smells acidic/rancid, don't use it.

I do believe you, Jake.

I was just ironic to the West manufacturer who is apparently a bit too optimistic about the storage time after opening.

To be sure just a final question: did you store the hardener in a special maybe disqualified way?

Jakes case may have been fairly unusual. The red stuff I used was at least 10 years old, stored in a non climate controlled building.

Not really. It stays in a moderately climate controlled room. I have no idea how old it was though.

This advice has also served me well when I was single...

The 205 is an agressive harderner especially for cold conditions and humid environments. So curing time is very short.
Normally you smell a strong pregnant ammonia odor when you put your nose above it. That's the amine.

Smelling acid however points at a partly reaction of the harderner in the tin. You confirmed that by noticing that the hardener/epoxy mixture didn't cure well anymore .
A possible cause for this pre-reaction in the tin is contamination with another chemical substance.

I'm also not sure what happens if there was leaked somehow a tiny bit of epoxy resin in the harderner tin.
Or maybe you wipped off the spout with a contaminated cloth.

Karl, as a male animal you ought to know how to use your nose and have an instinct for danger!

There was no cross-contamination. I use the pumps and usually buy a new set with a new batch of epoxy.

Jake, I think we will never know the cause of your contaminated harderner.

Next to a possible pre-contamination in the house of the manufacturer, there rests only phantasies about covert actions by terrorists,
by anti-catamaran people, or angry wife, angry children, angry forum members, intergallactical lifeforms, etc.

Anyway you were saved for real damage, because you used your nose wisely on time (unlike Karl).

My father used to be the chief chemist of a big paint manufactury.
So as a child I was used to go with him sometimes and play in the laboratories with all the glass instruments.
When I got older though my interest shifted more to the sometimes beautifull female laboratory workers.

Eventually I was banished by my father from his laboratories. But he learned me one thing: use your nose!

He had this particlar small movement with his fingers like waving the air towards him, in order to carefully smell the odor of chemical fluids.
With this little gesture he could also protect his nose hanging above agressive and harmfull acid's etc.

It was a pity that he used this gesture also out of habit in the evening above his dinner, which made my mother each time furious.
And made us kids secretly laughing ofcourse.

So, keep smelling when your are working with epoxy's.

just as a follow up...

I used my 2 year old west system epoxy to fill a small separation in the bottom of my port bow.
I dremeled a small slit, put in some hardened glass cloth, syringed in some west system (105/206) w403 and milfiber for body/strength , rough sanded and then put some gelcoat w/wax over it overnight. sanded and now i have a nice smooth clean spot on my boat.

no problems