well, it won't have to be completely air tight. get some rubber tubing from home depot or wherever and run it from the pipe so that you can hit it without making the helmet completely airtight. I think that will work best. Otherwise, every time you breathe out, it would come out the pipe and shoot your smokables everywhere. with my way, you can breathe out inside the helmet and your stuff stays put

This would be awesome to use with the bowl right on top in the silver thing.

The Kid
Kid Panda Reviewed by Kid Panda on . motorcycle gas mask ok, wwell, i got this motorcycle helmet that i want to make into a gas mask, and i know how im going to make it, im gonna drill a hole in the front, and put a tube with a bowl/pipe on the end, ut i gave one question, how do i make the bottom airtight Rating: 5