ah, but how WELL do you know it.

i think knowing scales isnt the important thing- rather how you use them. just going up and down the scale might be fine for some crazy shred routine, but in everything else, it gets boring. fast. just knowing the pentatonic scale is fine, but knowing how to work with it and learning how it works is much more important.

just working on your scales, thats great. run them up and down as a warm up. but writing a solo should show feeling. it should have the same energy as the rest of the song. a solo is making a point that cant be done with words.

sometimes a good place to start is acutally looking at other solos. get a tab for a solo somewhere and look at how they made it. identify the scales, the runs, everything. seeing how others do it can help alot.