I would get a different UV cure and verify the suggested wavelength. I use Alumilite's UV and a fingernail UV curing light and it cures in 3 to 5 minutes. I use to use Solerez and got the same results.
If you are having issues with hours, then the stuff you have is either separated (mix it), bad, or your lights suck.
I use Loon fly UV fly and knot cement with a small 9 LED hand held flashlight and it cures in seconds.
Something seems a little, OK A LOT, weird about your problem.