Craig Broady of Formlabs stated:
“Resin photo initiators are sensitive to a range of wavelengths in the spectrum. Lasers that emit at 405nm, like the one in the Form 1+, are inexpensive due to widespread use in Bluray players and the like. Using a 390-395nm wavelength cure box (or any cure box in the UVA range –– 400 to 315nm) is good for post curing our resin. I often use this one:”
And here is a post by Formlabs that uses nail dryers:
Easy UV Cure Box for under $30
So either you know something Formlabs doesn’t know, or nail lamps work. 