Hey there, thanks for the kind words on the video.
You will need a UV light source around 405nm wavelength to cure any uncured resin on the print, this will make the surface hard and dry allowing for priming and painting, otherwise the print will remain sticky.
You can use the ‘SUN’ a free source of UV light, or a cheap nail curing station will also work.
Here is a video showing you how to build a curebox for >$30. https://youtu.be/mahcMOpeZkM
The stronger the light source the less time you will need to cure the printed part.
If you have other questions just ask