The piece of glass is about 1/8 thick and 1.5 inches deep so I don't need to cut much. I only need to trim off about 1/4 inch (which makes using a hand-held glass cutter even harder). I'm pretty sure the glass is tempered.
Would a dremel with a diamond-coated rotary disc do a good job of making a smooth cut? (for example http://insidetrackclub.harborfreight.com/5-piece-diamond-mini-cutting-discs-31501.html )
Since the discs are so thin, I would hope to be able to make a precise cut by following the line and sneaking up on it as needed..
Would this work? Any other suggestions? ` Note: I tried using an angle grinder (with a metal grinding blade) and also a belt sander - but both of those approaches ended up more melting the glass (it got "yellow" hot) which caused it to crumble and ooze.