A Technician reports he signed-off a cockpit Smoke Goggle Inspection but could not reinstall the goggles on a customer's B737-300 airplane because the cabin entry door had been masked-off for a fuselage paint stripping procedure. Aircraft departed without the smoke goggles.

Narrative

I was doing [contract maintenance work involving] a Maintenance Visit-3 (MV-3) inspection on a Boeing 737-300 aircraft [for a major Carrier]. The inspection called for a Smoke Goggle Inspection. We were in a rush to put [paint] stripper on the aircraft; so when I went to return the smoke goggles; the [cabin entry] door was already masked [taped-off]. I returned the goggles to the Parts Bin with a part's tag. I did not fill out the Non-Routine Card (NRC); which I should have. The aircraft departed without the smoke goggles. I had been on [duty] for ten days; working 10-hour shifts. I was off for a holiday and when I returned the next day; the Air Carrier had called concerning the goggles. I received a written warning from my Supervisor; and the goggles were returned (how I don't know). I am not use to doing NRC's because in Airframe/Powerplant (A/P) school and at this FBO we do not use them. I had received a short two hour class about paperwork; but did not remember to do one [initiate NRC write-up]. I was tired and in a rush to do my job. I have both paint preparation and A/P responsibilities which need to be fulfill. I do understand now to complete Non-Routine Cards (NRC) and when to do them.