Originally Posted by Stratosphere

The FAR's are pretty generic in that statement too this is what it says
§ 65.77 Experience requirements.

Each applicant for a mechanic certificate or rating must present either an appropriate graduation certificate or certificate of completion from a certificated aviation maintenance technician school or documentary evidence, satisfactory to the Administrator, of—
(a) At least 18 months of practical experience with the procedures, practices, materials, tools, machine tools, and equipment generally used in constructing, maintaining, or altering airframes, or powerplants appropriate to the rating sought; or
(b) At least 30 months of practical experience concurrently performing the duties appropriate to both the airframe and powerplant ratings.
[Doc. No. 1179, 27 FR, 7973, Aug. 10, 1962, as amended by Amdt. 65-14, 35 FR, 5533, Apr. 3, 1970]

The rule of thumb I used to hear was 1900 hrs when it came to part 147 classroom hrs. But using experience to get your sign off I am going to say that 1 hr a month for 30 months isn't going to cut it..(I know that was just an example.) Again I guess it depends on which FSDO you go to with your experience documents whether they will except it or not.