Here's a trial version of a smoke generator out stock plumbing parts. It ran for about 2 hrs. Problem was the wood chip kept bridging and had to tap on it about every 20 minutes. Materials: 2-2 x Clos nipple 1-2 x 6 nipple 1-2 x 1/2 tee 1-2 x 3/4 tee 1-2 cap Expanded metal mesh welded in bottom nipple' After messing with it for a while, figured out I didn't need the 2 x 1/2 tee at the bottom. Now I am going to make one with 3" pipe without fittings so it won't bridge and runs longer. I'll post some pics later. If anyone has pics and suggestions it would greatly be appreciated.