I watched this video and was amazed at how large the exhaust vent was. I am wondering if he really needs a lid for that furnace having a vent that large, so what do you guys think?
He pulls a pretty small crucible out of the furnace, but maybe he has a large one that has close clearance with the lid. Even so seems like it might make the area above the crucible a cold spot. Other than that, too big! Best, K
Mine is 4 inch diameter and I often find myself partially covering it to keep the heat in. I’m kind of surprised he gets the brass up to temperature that way. 5 minute shakeout, petrobond, brass…. The smoke show was predictable. I’m amazed there was no fire. I doubt many will be back for the second heat. Pete
Probably shook it out early for the audience. Mine is about 3 1/2" and gets covered with ingots for pre-heating.
My vent is 3" I think if I was redoing it I might go with 3 and a half since flames tend to come out the side of the lid when on full tilt. Makes me think too much pressure builds up inside due to smaller vent hole. But its pretty close to right size.
