I'm waiting on a lens from China currently. Will be a while with the holiday and all. It will be nice to see the laser's true power once focused, but I do want to do some tests with a divergent beam, say 5cm^2 or so. I think to do a piece of toat you would need like a 60W or better laser, you're talking like 100 sqcm of coverage. You don't need a lot of intensity, just enough to cause higher temp gain than radiative, convective, and conductive losses to the environment at a decent rate. I know I can aim this 15W unfocused at a black anodized heatsink and after a few min I could fry and egg on the heatsink.
The hardest part is aiming a completely invisible beam, heh, not as easy as you would think. I would have had the candle lit in half the time if I could see or hold the 5lb candle still within a mm or so.