Leaving the stem in the bowl, they get coated with cake, smooth out and harden.![]()
I'd be worried that tamping directly on the "glue bottom" might cause everything in the chamber to land in your lap. Hold a shank-tray-less bowl up to a light... it's transluscently thin.
As designed, filling and tamping pressure is against the "tray", and wet, hardenable bits of ash & etc., gently fill the space below it. The bottom doesn't have to support much at all.
Take away the tray, and apply pressure & heat directly to the thin glue bottom? Might work, might not, but finding out could get messy and expensive (carpet, trousers, furniture fabric, etc.)





