I'm thinking of a thin coat of anything liquid (eg, resin from trunk of trees mixed with sugar and water). Answers ahould be aside from smoking the bowl half stacked and full stacked alternately, coating the pipe bowl with 50/50 sugar and water concentration, or using briar (I've got no issues concerning the type of wood, I use mahogany and tamarind wood for my bowl. scientific answers please... I'm a woodcarving artist in a bad shape when it comes to the utilization of my masterpiece.Help! lol! ; )