Hey there, Promise Epoxy pals! 🌟 Ever opened your epoxy hardener and thought, "Huh, why's this looking like a sunset in a bottle?" You're not alone! Let's dive into this colorful conundrum. 🎨
First off, it's all about oxidation - think of it as your hardeners way of taking a deep breath of air. Once it's manufactured, this oxidation journey begins. 🌬️ It's like an apple turning brown; totally natural but not always what you want.
"But wait!" you might say, "I've not even opened this bottle!" Well, here's the thing - even if it's sealed, those HDPE plastic bottles are like yoga pants - they breathe a bit. So, a tad bit of oxygen gets in and starts the yellow party.
Now, if you've played peekaboo with your hardener and opened the bottle, it's more exposed to our good old friend, oxygen. Hence, it goes yellow faster, especially if you’re dealing with a big bottle.
But here's the kicker - a little yellow doesn't mean it's game over. When mixed with resin, it's like a magic trick - abracadabra, and the yellowing is hardly noticeable! 🪄 However, if it's looking more orange than yellow, like a pumpkin in October, it's time to do a little test batch to make sure your project doesn’t end up looking like a Halloween decoration (unless that's your vibe, of course). 🎃
Pro Tips & Technical Info:
Got a hardener that's gone full-on yellow? Pair it with dark pigments, tints, or dyes. It’s like a new life for your old friend. And for those crystal-clear projects, maybe grab some fresh epoxy resin.Many customers will use yellowed epoxy hardener in their work with dark pigments, tints or dyes; and acquire new epoxy resin for their crystal-clear epoxy resin projects!
If the epoxy hardener is dark yellow or orange in color, the product may have passed its expiration date, stored in extreme temperatures or exposed to UV rays. The epoxy resin should still cure properly, but a test batch is recommended to ensure that the finished, cured results are not discolored to dissatisfaction.
So there you have it, folks! Yellow hardener isn’t the end of the world. It’s just your epoxy showing its true colors. Keep crafting and keep creating wonders!
Curing is a chemical process employed in polymer chemistry and process engineering that produces the toughening or hardening of a polymer material by cross-linking of polymer chains.
https://en.wikipedia.org › wiki › Curing_(chemistry)
or "hardener" can change in color over time due to several factors, including the shelf life, chemical reactions, exposure to light, temperature, and moisture, and the presence of impurities. These different factors can cause the epoxy hardener to become yellow, orange, and even brown over time.
Oxidation turns the epoxy hardener yellowish over time. This starts to happen when the container of the hardener is opened for the first time and air is allowed to enter. The degree of discoloration depends on the amount of exposure. This also means that hardeners placed in larger bottles may be more affected.
This product is not intended for permanent outdoor use or direct UV exposure. It does contain UV inhibitors to help resist yellowing, but all epoxy products will eventually begin to yellow. This includes base resin, current agent, as well as the finished products.
The hardener oxidizes from oxygen which can discolor it slowly while stored over time. Sometimes the user believes it is not good (hence throwing away). Reality is the material may still be good, but just does not look the same. As always, please test a small amount prior to any large installations.
In most cases, the yellow hue of the hardener is not going to be noticeable unless applied over light colors or poured in thick layers. Once the epoxy resin and hardener are mixed together the mixture will appear more clear, and then when applied as a coating it typically is completely clear.
Epoxy shelf life can last many years when resin and hardener are properly stored at room temperature and in closed containers to prevent contamination. Those who have used polyester resins know that its shelf life is only about six months before it turns to a useless jelly-like substance.
Yellowing of the hardener part B in epoxy resin can doesn't affect the properties of the hardener. In general, yellowing of the hardener part B can indicate that the hardener has been degraded by exposure to UV light, high temperatures, or certain chemicals.
Some resins may take only a few days of direct UV exposure to start turning a clear resin to an oxidized yellow while others may take months to notice. It is an effect that oxidizes and degrades more and more over time.
That's why RESIN HAS A SHORT SHELF LIFE. But just because your resin hardener has yellowed, doesn't mean you have to discard it. In most cases, it will still cure properly... it just won't be as clear as fresh resin.
If you add too much hardener to an epoxy resin system, it will decelerate the curing process, leading to an improperly hardened and non-functioning product. This makes it crucial to have the right ratio of resin to hardener if you want to create an epoxy system that truly works.
Wait a while longer, resin will cure if the hardener is less than needed, it will just take more time. Not all Epoxies are equal amount, some of them take two parts resin to one part hardener, and they all have different curing times.
Resin (Part A) can actually be cleaned up with white vinegar, as can some hardeners (Part B). But solvents such as lacquer thinner, denatured alcohol, and acetone will be the best choice for cleaning up any mixed uncured epoxy. Once the epoxy is mostly cured, paint stripper or heat will be required to remove it.
Resin yellowing is mainly due to the change in molecular structure caused by hydrothermal or UV radiation, leading to the change in color and mechanical properties [28].
ArtResin epoxy resin is properly stabilized against the degradative effects of oxidization and UV light to prevent and significantly delay yellowing, aka ambering, aka browning.
In addition to hydrolysis, exposure to high temperatures can cause the epoxy coating to yellow through a process known as thermal degradation. High temperatures can cause the epoxy molecules to break down and release volatile organic compounds (VOCs), which can react with oxygen in the air and cause yellowing.
Products called “nail hardeners” contain formalin, dimethyl urea or glyoxal: these three chemicals often have a nail hardening effect, but they also prevent the nail from being as flexible as it normally is, potentially creating a brittle and slightly yellowed nail.
Use a fine-grit sandpaper or a floor sander to gently sand the yellowed areas of the epoxy floor. The goal is to remove the discolored top layer and expose the fresh, unaffected epoxy beneath. Be careful not to apply excessive pressure or sand too deeply to avoid damaging the floor.
Introduction: My name is Gregorio Kreiger, I am a tender, brainy, enthusiastic, combative, agreeable, gentle, gentle person who loves writing and wants to share my knowledge and understanding with you.
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