If the flame from the arc is directed right at the filter I see no reason for it to crack the glass. Some serious flaming is needed to crack it. The only 1 time that ive heard of this happening is by a member in another thread. Im still not sure weather it was caused by the flame or faulty glass piece.

I will even go so far as to say (please dont go burning yourselves and always excercise caution)  that when I use my GVG and Arc im able to pull the diffuser off the pipe to clear the pipe of any vapor(hence i never grown them xtals in the GVG like ive seen posted) at the end of my hit with no discomfort whatsoever.

Chronic, what type of butane are you using? And are both the vector and arc filled up with the same butane? I ask because endless brought up a good question about butane, and im puzzled as to why you tasted gas. This has never happened to me, although ive never just used the GVG and arc with nothing in it.

endless, I use "Newport, extra purified butane lighter gas", would be nice if we could get MSDS for the butane and compare.