I just got a new LVLP sprayer (read NEWBIE) and plan on spraying some shop cabinets with WB poly (leaning toward one of the Target or General Finish products). I have spent several hours looking through posts on this forum and see that many people spray a thin coat of shellac (to seal the grain I think) before spraying the WB coats. Is a shellac sealer really necessary or will most of the WB polys also seal the grain? Second, if I use shellac, can I use either alcohol or WB shellac? Finally, can standard alcohol based shellac be sprayed without an explosion proof fan? Thanks for you help.