Batch 2018-batch-02

4 grains 80mm long for 54mm cases, with 0.5 inch cores

These grains were cast as a demo for college students on Monday.

The simulator says we need 200g of fuel per grain, so the batch size will be 800g (plus a bit for the pan made up by re-melting previous scraps):

• 65% KNO3, 520g
• 35% Sorbitol, 280g
• 1% red iron oxide, 8g, added after melt
• 12 drops Polystep-B1, added before pour using eye dropper

This formula is completely fluid with 225F indicated on the Presto Multicooker, but viscosity is noticeabley lower making for easier pouring at 250-275F.

Grain fill lines 73.6mm from the bottom of the casting tube.

These grains were cast on 2018-12-17.

Results

• Grain 1, 198.8g gross, 5.78g casting tube, 193.0g net propellant
• Grain 2, 194.1g gross, 5.82g casting tube, 188.3g net propellant
• Grain 3, 196.6g gross, 5.78g casting tube, 190.8g net propellant
• Grain 4, 201.1g gross, 5.80g casting tube, 195.3g net propellant