A device for curing an obscured photosetting compound in a subassembly part has a base for supporting the assembly and a plate mounted to the base. The plate has a lens that concentrates UV light into a narrow slit in the assembly to quickly cure the compound. In an alternate version, the plate has a parabolic opening with a mirrored surface for gathering the UV light. A third version of the invention uses a rotatable fixture to position the assembly beneath a UV laser light source to cure the compound.