Home-made Vaporizer/ Vaporizing Stems?

[callmitony]

Swim recently constructed a rather crude vaporizer using a "temporarly borrowed" glass testube with plug and straw. A candle was used underneath the testube rack and everything seemed to be going fine until the marijuana reserves hit an unexpected low.
A slightly less the sober SWIM decided that this was a good time to try vaporizing all of the stems he had been saving over the past week or so.
From there on the story gets a little hazy. But enough beating around the bush...
Does vaporizing cannabis stems produce THC vapor? worth saving stems for?
yea or nay !?!?!?!