Last Night i made a fountain with iron powder and aluminium powder.
I had 3 parts Bp to 1 part iron powder in the frist fountain and that went fine.
But then on the larger fountain i did pretty much the same 3 to 1 mix with aluminium powder. I layered the mixes up so that it went (from the bottom) Iron, aluminium, iron, aluminium. and then just befor the clay choke i had some plain BP.
It was certainly a good fountain with an amazing start! but afer it had cooled on close inspection it had LOADS of slag around the top of the choke?
I wasnt sure why this was because there wasn't any on the first fountain.
When pressing, I hope, your fountains. In between each layer or every so often press a small layer of BP in to help clear the choke up. It kind of blows any blockage out of the way. I cant remember where on here but I think Ive read it is a good solution to helping prevent catos if your fountain starts fine then boom.