Had a little fun with a 39j spinoff.
Replaced half the aluminum with 80-200 mesh Mg/Al, and replaced the +2.5 Mg/Al with 30-80 Aluminum. Funny, I know, but it's all I have to work with ATM. It was still pretty.
I used a little bit better confinement than usual but only reduced the booster by 20%. The result was that most of the stars got smashed. Just going to remember to either lower the booster more or use a little less confinement, or possibly just add another point or 2 of dextrin to the stars. It seems that 39j uses 1 less percent of dextrin than regular 39. Not sure if that's a misprint or not, but felt like I've seen it that way on more than one source. Anywho, here's a little video of it in action.
Will probably upload another vid of the same formula with just a bit less confinement to see if the stars live this time. Also I will get some "proper" coarse Mg/Al soon enough to do "actual" 39j with the 2% carbonate prime (these were unprimed.) Oh, and the charcoal used was Southern Yellow Pine. Made my kiln smell like Pine-Sol for a few days. Other Al used was Eckart 120.
Edited by PhoenixRising, 11 June 2016 - 08:35 PM.