where can i get solid oxidizer?

[Dang911]

are you making candy rocket engines, or smoke bombs, not that there us much difference. YES the double boiler is an essential way to making a good consistent engine. Almost equaly as important is the premix. No exaggeration, you really have to mix it for 5 min by hand. Then you can put all the DRY chemicals in the double boiler and begin to heat it till the sugar starts to melt into a gue.