Please don't let your brother in law cut the keggle with a TORCH we weld stainless steel all the time and a torch will distort the stainless and make the keg worthless. A torch will render to much heat in a concentrated spot and distort the sorrounding area. The correct way is to use a plasma...
It seems that every time I use this yeast and make a starter of about 500 to 800ml per 5 gallons, I have to use a 6.5gallon carboy with a blow off tube or I have a closet full of brown slime. This yeast has a violent fermentation of about 72 hours. There is no doubt that fermentation is taking...
I really don't measure efficiancy with my propane, It's brewing I don't really care!!!! The pot that your that you speak of, is a wind guard to keep the wind from effecting the quality of the flame.