These are 60min Great Planes Epoxy. The yellow component has turned somewhat thick and white-ish. -Is it normal? I just mixed some to see if it cures right.

All adhesives can go bad over time once exposed to oxygen for the first time and is why they come in sealed containters. Once you've broken the seal you're on your own.

Plugin,

No your epoxy is not bad, but it needs some help!

What has happened is the molecules of the "A" side or the resin have lined up for some reason. This happens more often in colder climates or storage areas. To fix the problem put that side in the microwave for about 15 seconds, this will excite the molecules and clear up the problem. After you have "Nuked" material shake it up to speed the clearing of the resin. Usually one shot will do it.

Be careful not to over heat as it will melt the container.

Wait until the A side cools to room temperature before using or potlife will be greatly reduced giving you a much faster cure if used warm.

Wow I just put it in the microwave and I'm waiting for it to cool down but it did clear up a lot! Thanks Steve.

This can also be done by submersing the bottle into boiling water for a moment.

Microwave? I know how the Microwave works but that's crazy. Hey Plugin, ccan you tell us the result buddy? I'm very curious. [8D]

I went to use some 30 minute epoxy once but it was taking forever to flow down the bottle. I microwaved both bottles for about 10 seconds and that helped the flow. I used the epoxy to mount my FourStar 40 landing gear.
Although this is not a scientific test and I have not tried pulling on the gear, it's been about a year I have had many landings (some a lot rougher than others) and gear are fine.

Learn something new every day....

Wow, and I've been throwing mine away.

Thanks for the tip!

Yeah. Who would have thought about that? Microwaves are bad for the food and so for human, but good for our epoxies

Not to get into a debate that is off topic, but microwaves are perfectly safe for food. They are only unsafe to humans if you are directly exposed to them, as they work by energizing water molecules.

Be careful when heating in the microwave, though, as it will get very hot very fast, and I have seen those bottles start to get soft. One would assume that with enough time, the bottle would actually melt.

This is why submerging in boiling water is my method of choice! It is much more controlled.

Osirisf16, it's an excellent result. The epoxy is now clear like the day it was bought. It's amazing how well this works. I gave it 20 seconds in the microwave, it came out very diluted and when it cooled down it was like new.

Yes the bottle will melt, plus the epoxy is going to outgas in the microwave, lots of esters in epoxy that are not good for you.
I don't even use boiling water, what ever temp it comes out of the tap will get the job done just fine.

Yes, there are going to be epoxy fumes which one doesn't want to directly inhale whether its warmed in water or in a microwave or just using the product.

A short 15 second warming is hardly going to out gas much, over doing it can cause problems. Any type of warming method like warm to hot water as suggested will do the trick. Setting the material on dashboard of a car in the sun will have the same result. The idea is to scramble the epoxy molecules by increasing the Brownian motion with heat. To much heat could certainly collapse the plastic container so caution is advised, as I gave warning.