why would a pipe destroy 50% of the THC??

I think the only THC that u lose when u smoke in a bowl is the resin that the smoke make, but i wouldnt say it looses 50% of the thc man its way too much.
Musician Reviewed by Musician on . smoking from a pipe destroys 50% of the THC? i read here http://www.onlinepot.org/medical/vaporizer.htm that smoking weed from a pipe destroys half the THC. i dunno if its true, but they have instructions on how to make a vaporizor, which saves 45 percent of the THC. so if someone tries this out, tell me how well it worked. Rating: 5