Why does my UV resin not cure completely? Why is it still sticky?
There can be many reasons why your UV resin is not curing. In this article, I explain the most common mistakes.
Not long enough under the UV light
The curing duration given for UV resin applies to clear resin. If you use pigment you have to leave your piece longer under the UV light.
A UV flashlight has much less watt than a UV nail lamp (typically 36 watts). If you use a UV flashlight and do not have a UV nail lamp, you can put your piece in the sun to cure. Also, check the batteries of the UV flashlight. If the batteries are too weak, the lamp will not generate enough UV light.
UV LED nail lamp
There are also UV LED nail lamps on the market. Some of them are unsuitable, even if they have more watt. If you want to be on the safe side, get yourself a halogen UV nail lamp.
silicone mold not suitable
You need a clear silicone mold for UV resin, otherwise, the UV light will not cure the resin completely.
Too much pigment
The ratio of UV resin to pigment is not correct. Pure pigment, even UV resin pigment, does not cure under UV light. You have to mix it with enough UV resin.
White and black pigment, mixed colors, as well as some powder pigments, give an opaque, non-transparent color. UV resin cures only where the UV light can reach. If you use opaque colors, you have to work in thin layers and cure both front and back. You should also apply a final coat of clear resin.
Unhardened UV resin has a minimum shelf life of one year. Although it can certainly be used longer, it eventually ceases to harden properly. It is then noticeably more viscous.