Batch 2018-batch-02

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

These grains were cast by college students after I did a demo batch.

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, 193.4g gross, 5.78g casting tube, 187.6g net propellant
• Grain 2, 192.5g gross, 5.87g casting tube, 186.6g net propellant
• Grain 3, 190.8g gross, 5.83g casting tube, 185.0g net propellant
• Grain 4, 195.1g gross, 5.79g casting tube, 189.3g net propellant