I have a bottle of Threadmaster Lite purchased last year. It has not been opened nor has it been exposed to freezing temps. It has turned to a light amber color. Question, will this efffect its function or color of the cured finish?

No it does not, all hardeners will change color over time to an amber color. Your finish is FINE.

DR

Mark,
Although the hardner will work fine - I personally don't like to use hardner if it has changed color.

If it was my bottle, I would pitch it and get a new one.

That is one of the reasons that I think it makes sense to not go over board on buying supplies that do show age effects due to storage.

When I used to work in another industry and used two part epoxy paints, I had the same issue. i.e. the hardner changing color and affecting the paint finish.
There was never an issue with the pigment, only the hardner. As a result, I made sure that I have enough hardner on hand, but just enough.

I expect that you can use the product and be just fine, but its each persons preference.

My feeling is that if a product has one characteristic when new for the first year or so of its life and then changes - why would you want to use that product if it has changed?

Take care
Roger

The product hasn't changed and there is nothing wrong with hardener that has ambered - it is going to amber in the bottle and it is going to amber on the rod. Either way, it's going to turn slightly darker. This is true even if it's clear when you mix and apply it to the rod.

The hardeners in most epoxies are going to turn slightly amber within just a matter of a few weeks so if you plan to keep perfectly clear hardener on hand all the time, well... you're going to be buying new epoxy kits every other month. And remember, it will still turn amber after it's mixed and on the rod.

It is also true that the UV inhibitors in Threadmaster actually contribute slightly to an off color in the hardener - a very slight discoloration there is normal due to the coloration of these additives.

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Thanks to all for the comments!

Tom,
Wouldn't it make more sense to get a finish which wouldn't change color as a function of age?
Roger

Yes, but no such finish epoxy exists. The epoxies we use in rod building contain amine hardeners which all discolor due to age and heat. There are many other things that can cause of colors and terrible yellowing or even browning of the epoxy, but even in the most perfect state, the nature of these beasts results in some ambering of the hardener (or finish) over time.

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Tom,
Thanks for the update.
Roger

If you know of something that does, in fact, stay perfectly clear. please advise. There would be plenty of guys that would like to know about it.

PermaGloss stays perfectly clear, but it doesn't provide the same look as epoxy.

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I've got some Amtak finish that I have had for over a year, now, and both bottles are water clear. The Amtak product seems to be slower at changing color than any epoxy hardener that I have seen. Amtak finishes are not inexpensive, but I am very pleased with the ease of use and the finished look of the application.