I have been working a lot with resin lately and it is one of the most versatile crafting mediums I have ever worked with. Resin is very durable and waterproof but does that mean that resin can also be used outdoors?
Resin can be used outdoors because of its high durability and water resistance but special resin with a high UV resistance has to be used to keep it from yellowing when exposed to the sun. The resin will yellow eventually no matter how high the UV resistance is but that can take many years.
There are a lot of different types of epoxy resin and all of them can be used outside as they are all waterproof and don´t get brittle easily when exposed to the elements.
But resin will turn yellow when it is exposed to the sun so you have to make sure that you are using a resin with a high UV resistance for outdoor use.
Even resin with high UV resistance will yellow eventually but that can take multiple years of direct sun exposure.
How to Keep Epoxy Resin From Yellowing in the Sun
Sun is really the greatest danger to resin. UV rays will break down the resin which will first lead to yellowing and eventually even makes the resin brittle.
But there are a few things you can do to ensure the longevity of the epoxy resin.
Use UV Resistant Resin
The easiest way is to use UV-resistant resin.
This type of resin has additives mixed into it that will give the resin a higher resistance to UV rays. But even that won´t protect the resin forever.
Eventually, after many years, the resin will still start to yellow and then become brittle.
You can also mix additives directly into regular resin that will make it more UV-resistant.
I generally don´t recommend this approach because you have to mix them very well into the resin to ensure the additive is equally present throughout the resin.
Also, some resins don´t like being mixed with too many additives and may not cure properly anymore.
I personally prefer using UV-resistant resin from the start as it is simply easier and more convenient to use.
You can either paint the resin with UV protective paint to keep it from yellowing.
The paint can be stripped or directly replied to the resin after a few years to ensure constant protection against UV rays.
This is probably the best way to protect the resin from UV light permanently.
Only Use Resin in Places Where it is not Exposed Directly to the Sun
You can also use resin in areas where it is not exposed directly to the sun.
This way the resin will last a lot longer as it is only hit by UV rays indirectly. And you don´t have to worry about it turning yellow or becoming brittle for a very long time!