Most two-part resins on the market are epoxy resins that don't require UV light or special environmental conditions to cure. Although they can cure faster at warmer temperatures, they don't need UV light to harden.
UV resin, also known as monocomponent resin, is the only type of resin that needs UV light to cure. However, it can be cured without a UV light source by leaving it at room temperature for 72 hours.
An oven or heat lamp can also be used to cure clear silicone rubber molds with this method. In the case of UV-sensitive resin that needs UV light to cure, direct exposure to sunlight is sufficient to harden the resin, although it may take longer than with a professional UV curing machine with high UV wavelengths. Epoxy resins are a popular choice for many projects due to their strength and durability. They are easy to use and don't require any special equipment or environmental conditions to cure. However, if you're using a UV-sensitive resin, you'll need a UV light source or other curing method in order to harden it.