# Batch 2019.06.21 #

A total of 12 3" KNSB grains for 54mm cases.  These were cast in two batches
that each consisted of a two 9" casting tubes, one each with 0.5 inch steel 
and 0.625 inch Delrin cores.  One batch was pure KNSB, the other was my usual
mixture with RIO and Polystep-B1 surfactant.  Simple pour, insert coring rod,
top off grain.  No vacuum processing or vibration.

The 54mm casting tube I'm using weighs 1.9g per inch.

The purpose of casting these grains is to do test stand burns of identical
motors in each of the two propellant variants, so I can tell how much the
RIO is affecting ignitability and burn rate.

These grains were cast on 2019-06-21.

## Results ##

Batch with RIO:

* Grain 1, " long, 0.5" core, g gross, g casting tube, g net
* Grain 2, " long, 0.5" core, g gross, g casting tube, g net
* Grain 3, " long, 0.5" core, g gross, g casting tube, g net

* Grain 4, " long, 0.625" core, g gross, g casting tube, g net
* Grain 5, " long, 0.625" core, g gross, g casting tube, g net
* Grain 6, " long, 0.625" core, g gross, g casting tube, g net

Batch without RIO:

* Grain 7, " long, 0.5" core, g gross, g casting tube, g net
* Grain 8, " long, 0.5" core, g gross, g casting tube, g net
* Grain 9, " long, 0.5" core, g gross, g casting tube, g net

* Grain 10, " long, 0.625" core, g gross, g casting tube, g net
* Grain 11, " long, 0.625" core, g gross, g casting tube, g net
* Grain 12, " long, 0.625" core, g gross, g casting tube, g net

The mass per unit length was within ?g/inch.