I have a DIY query regarding the bubbling/filtering of smoke though water. Take a look at the following image, just as a start guide: http://www.artisan-distiller.net/phpBB3/download/file.php?id=1676 If a set-up was made using steel (iron) pipes similar to what's shown, where the left-hand vertical pipe was sealed and filled with wood chips, but instead of using an external air-blowing source (shown as an aquarium air pump) - an external heat source was applied to the bottom of the vertical pipe on the left (e.g. burner, or hot coals)....would enough "smoke pressure" be built up so that the smoke would be forced to bubble it's way out through the water? If so, would the water have any effect at trapping some of the tar and creosote bubbling through it? But overall, the main issue is whether or not enough pressure would be built up by the external heat source, where they only way out for the smoke is through the water. I can guarantee that a high degree of heat and smoke would be built up within the left-hand pipe. The other query is the same filtering concept, but instead of water....having the secondary vertical pipe (on the right, with the opening at the bottom) filled with some sort of steel wool - either fine steel wool or coarse stainless steel wool. Would this have any filtering effect at all? My apologies if I was clumsy and confusing at explaining this. I don't know if anyone can help me here, but I'm hoping someone might be able to help. On a side note, some commercial cold smoking businesses do use this idea of filtering smoke through water. Thanks all.