dankshizzle
Well-Known Member
actually they do. if you read about the vin pin it says it will put little fracture spots where the air is trapped inside. thats why they usually use it on marbles, not bongs. the glass would be thinner in the spots the bubbles are and inconsistent in thickness. which is fine for marbles. but the wall of a tube would sketchy. and you have to implode the air into the marble. would be hard to do to tubing. especially consistently in a pattern.