Tried to search but couldn't find much, sorry if its already been posted.. I'm relatively new to all this, I currently own one bong but a while back I tried out a vaporizer and fell in love. I'm looking at the volcano vape, there's a used one for sale on craigslist but I'd like to know what to look out for, such as common things that can go wrong? its a classic volcano, used for one year, owner claims its in good condition and I haven't seen it yet.. any advice is appreciated!