Mixing And Casting Rocket Propellant - Simplex Ep 2

Thanks to Charlie Garcia for teaching and helping me build this motor: @AstroCharlie

Some places to look if you want to learn more about solid rocket motors:
Charlie also has a great series of videos about solids on his channel: @AstroCharlie

0:00 - Intro
0:46 - APCP Components
6:19 - Bespoke Post Ad
7:33 - Safety
10:35 - Mixing Preparation
12:14 - Mix Paddle Issues
12:50 - Mixing the Liquids
13:33 - Vacuuming the Liquids
14:09 - Adding the Solids
14:39 - Adding the Curative
15:07 - Vacuuming the Propellant
15:29 - Pourable vs Packable
16:55 - Prepping Liner for Casting
18:01 - Casting Hardware
18:37 - Prepping Hardware for Casting
19:04 - Packing Propellant
19:29 - Removing Casting Hardware
20:47 - Voids in the Finocyl
22:15 - Other Resources
22:55 - Outro

For more info:

[Mozartenhimer]

This is insanely interesting content. No intention of making a solid rocket, but still here to watch

[AstroCharlie]

Every time I see that void filled finocyl my eye lets out a single tear...
Next mix we're gonna nail the density!

[DontForgetYourDreams]

The safety precautions you stress so much are absolutely valid!
When I was 20 (13 years ago), I also made solid rocket propellant (Amonium perchlorate) with my friend who is chemistry PHD today. I mixed the aluminium powder with the amonium perchlorate powder when they were still dry powder. Dust must have settled in the air and a spark must have been generated somewhere. There was a huge explosion and my right hand was completely destroyed, my left hand only partly. My eardrums were ruptured and I had chips of the ceramic mortar we used in my eyes. As it came close to a fragmentation grenade the chips also went into my chest and almost killed me because they came close to my lungs besides the extreme blood loss I had.
10 surgeries and 4 months inpatient later I was in my rehabilitation phase and I am just so grateful to this day that I survived, that I can hear and see and that I can still enjoy this amazing life. Btw today I am an aerospace engineer :)

[pepperparkerwrites]

As a baker who has scraped down many a mixing bowl… consider getting a bowl scraper to clean the sides! It’s much easier to use and much more through than an actual spatula. 15:00

[wesselscreations]

Do you measure the containers after pouring to get the exact amount you actually used in the mix?

[SpacePotatoFilms]

I'm a Space Potato from the future here to let you know that while Elon may be the one that got us to Mars it was Joey B that got us to Pluto

[wgoulding]

Hello! I'm a professional, I work at one of the handful of companies in the US that make solid rocket motors for NASA, the DoD, and the DoE. Watching this was extremely difficult. Yes, everything worked out, but there was so many opportunities for things to go very badly. I didn't see proper PPE (flame retardant lab coats, face shields), I didn't see de-ionizers, I didn't see personal grounding devices, and I didn't see the casting tooling and motor be grounded when it was pulled. The separation of the tooling from the propellant grain can create large static electricity charge build-ups. Also, sawing a propellant grain of that size, yikes. I'm not in the safety department, I do design, so there's probably more than that.

[wesselscreations]

If making again in the future, maybe having a massage gun or something similar nearby, for if it becomes a packable motor. Could vibrate the casing like when casting concrete, to help liquification and reduce bubbles around the more complex geometry.

[wombatillo]

These kinds of thin nitrile gloves aren't really chemical protection gloves. In a professional environment you'd be needing to use much thicker gloves with longer sleeves. (and nitrile assuming nitrile is the optimal material for protection for these chemicals) edit: American Chemistry Council suggests light polyethylene inner glove and light nitrile outer glove for light-duty use and thicker pe/eval inner glove and nitrile outer glove for heavy-duty use. I doubt manually slathering isocyanates in a rocket motor is considered light duty use. A single 3 mils layer of nitrile rubber worn for +60 minutes in possible contact with the chemical is probably suspect.

[fullflowaerospace]

cherry limade sounds so good, i mean, its literally just cherry, lime, and lemonade mixed together. its also really hot.

[TheExplosiveGuy]

I've been building my own APCP motors for a while now, this was great to watch. It's kind of funny watching you go through all the same hurdles that I went through, like the intended pourable fuel that turned into a packable fuel, the PITA vacuum process of trying to keep the fuel off the vacuum lid, the voids in the finocyl and the liner OD not matching the case ID, it's all part of the learning process lol. If your fuel is only packable, i found that its necessary to vacuum fill the case, where you make a vacuum chamber that the case fits into, and at the top you have a funnel and ball valve which you pour your fuel into, then once the chamber has been evacuated you open the ball valve to allow the fuel to start pouring in. Once it is fully filled, any voids in the fuel will collapse after releasing the vacuum, and you take it one step further by inducing vibration into the tube as it fills to allow better settling.

[phoenix]

When I was an intern for ISRO (Indian Space Research Organization) they used TDI (Toluene Di-Isocyanate) as the curing agent and was treated the most carefully out of all the chemicals. It reacts violently with moisture to solidify so if you inhale it it solidifies in your lung and windpipe. (So yeah pretty bad) Tho it can be neutralized using ammonia so everyone had a bottle of ammonia and water mixture (they called it Anti-TDI) and another intern there dropped the bottle and the whole room smelled rancid for a week, and the cleaning staff was not pleased.

[stevato]

joe please let me taste your propellant please joe it looks so yummy I want to eat it the propellant I want

[tannky]

Don't mix next to a scented candle, ok got it ill mix only next to unscented candles xD JK awesome video, so well put together and loved how you explained all the safety procedures to drive home the point about how dangerous this can be and make sure if anyone tries this they are as safe as they can be!

[sonicsupersam]

2/10. You didn’t write a whole essay on your life before starting the recipe.

[justspace]

It’s super weird to see something you’ve been doing for 4 years explained so eloquently. Awesome video Joe! Can’t wait for you to discover more about the mixing process!

[voxelmaniam]

Well done. I'm really enjoying this series. Personal note: In the mid 90's I worked for a company that produced software for visualizing 3D volumetric data. We received an inquiry from NASA asking if we would be willing to do an analysis of a phantom (non reactive) rocket motor CT scan that was part of a study they were performing. The goal of the study was to identify effective non-destructive testing techniques for man rated solid fuel rocket motors. The data set was from a test article that had experienced a malfunction in the thermal controls while the propellent analog was curing. This resulted in massive stresses building up in the fuel that literally tore it apart. They wanted measurements of the tear surface area and volume of the open space. This was a really neat project and got me a trip to Huntsville AL to demonstrate how we did the analysis.

[BreakingTaps]

Instructions unclear, my cookies exploded in the oven. 😅

I know cutting it in half probably wasn't anything to worry about regarding sparks/accidental ignition, but sure felt like it would have been scary regardless! Even though I'll probably never make my own rocket propellant, was a really interesting video! Can't wait to see the next one

[bbrockert]

One more nuance to the propellant making legality: in the US, transporting a live motor on the road and transporting a motor across state lines can expose you to new and exciting regulation like the DOT and rules around interstate commerce. If possible, making the rocket at your launch site can dramatically simplify the legal framework.

[wouldntyaliktono]

When I was a senior in high school my chemistry teacher decided to sponsor our student rocketry club. He was one of these old-timers who wasn't fazed by much, and just wanted us to have fun learning. And he let us do all sorts of cool stuff with static thrust tests and airframe designs, and casting our own Sugar/KNO3 motors. But the whole club had shut down when we blew our test stand (a tree stump) in half because of voids in the propellant grain.