Not much! I cover the inside of the neck with the templac on three pieces of brass. I can usually dial the timer right with three. Steal a couple old bread baking pans from your wife to catch the brass.
Add: I went to the internet and bought 2 torch heads with 3 or 4 foot hoses that attach to the small tanks. The small tanks are pretty cheap these days and I can anneal thousands of brass before they need to be replaced. I thought they would be safer to use and keep in my shop than the big tank. Possible leaks and all.
The machines are great. It goes quickly. I think you’ll like it!
Could you post... a link to the hose you use?
I made a little kicker out of a piece of aluminum flashing to push the brass into the baking tin.
That little kicker is a swell idea - thanks.