okay so i've been wanting to make a homemade for awhile (just for fun) but i've had the hardest time finding a bowl...i would have used my old trombone mouthpiece. but. its in storage across town. so since i couldn't find anything i began tearing the house apart for a bowl. i found one of the cable connectors (female) that had the wirepulled out of it. it is the best homemade bowl i've found. its small. so the pipe i made is pretty much a one hitter. but i do have my bowl problem solved when i decide to make a bong. *note* dont tell me i should just use glass pieces...i have my one hitter and a couple pipes. only reason i dont have a bong is because i am stealth toking at my parents. the bottle pipe was just for fun The pipe: the smoking device itself is actually a mountain dew bottle, with a hole cut in it, a pen tube, and the female cable connector with some foil down to keep it clean. not bad for maybe 20 mins of work (10 of that finding a bowl) the "slide" is where the pen tube attaches. its smooth and air tight. so just like the tube out and enjoy. hits like a champ. the reason i said it was a one hitter is because the cable connector is just a small bowl. its good for a constant green hit and then cashed.
I really would reccommend not using a pen as a downstem if it's plastic. If it's passing through it right after you ignite it chances are it's going to give off fumes.
I think I know what you mean. You can get very similar peices at home depot or lowes. The big ones have huge holes at the bottom but u can use a screen out of ear phones and it works perfect. Or the smaller ones have little holes. Personally I just use sockets for bowls everytime and just make a filter out of something. Ive made a design to use my glass pipe as a bowl in a homemade but havent gotten around to making it as it requires some supplies and im broke.