Sciencemadness Discussion Board

Propellants for SRBs

cryomancer - 30-3-2016 at 11:49

Recently there have been a few posts on solid fuel for rocketry and after reading the posts they reminded me of my attraction to ammeter rockets.

So I was wondering of anyone had any ideas for solid propellants and the chemistry describing them.

Everyone knows about the KNO3 and sugar mixture but im looking for something else that might give more power or a greater Specific Impulse. It does not matter if they require some obscure chemicals I just would like to know what is out there.

a nitrogen rich explosive - 30-3-2016 at 14:34

Lithium perchlorate and sugar works well. EXTREME DANGER - LiClO4 is highly corrosive and extremely toxic by inhalation or ingestion. However, it does have a 61% OB, making it a powerful propellant

cryomancer - 30-3-2016 at 16:41

When you mean the OB you're saying the oxygen balance and the closer to 100% that is the better the compound is at burning efficiently. Am I correct in saying that

On another note went to Lowes and picked up a lb of Spectracide Tree Stump Remover and looked at the MSDS and it said 100% and so I finally have KNO3 and I swear I was way too happy after I walked out

[Edited on 31-3-2016 by cryomancer]

hyfalcon - 30-3-2016 at 17:32

BP is still the best propellant for beginners. Potassium nitrate and sugar are okay, but the motors don't store well. They must be made and used, anything anymore exotic is NOT for beginners. Your more exotic mixtures usually must be pressed, not rammed like in black powder rockets. Don't care for the idea of whacking on whistle mix, could make for a Darwin kind of day.

[Edited on 31-3-2016 by hyfalcon]

cryomancer - 30-3-2016 at 17:58

What im tiring to do with this topic is just to get any recipe of solid fuel for beginners or for licensed professional. This is purely just share what you know

Your post is not off topic i just wanted to make sure that we dont go for just beginners only

[Edited on 31-3-2016 by cryomancer]

Chemist_Cup_Noodles - 26-4-2016 at 09:21

So if you are going for a little farther than plain beginner mixtures, you could go for some chlorate or perchlorate mixtures. Some good examples are actually still close to the classic KNO3 and sugar mixes, but should have a much better energy density and specific impulse. I've been hunting down another similar thread I saw where this guy experimented heavily with these mixtures but can't find it.

If you want something very different, consider a mixture similar to the "zincoshine" used by Homer Hickam Jr of NASA and Bocket Boys fame. But instead of zinc powder aluminum powder should yield good, possibly better, results.

Also, try experimenting with different compounds to increase burn rate. I've found that sodium metabisulfite does really quite well in this manner. Sometimes when I try to light a slightly wet mass of it, it produces gas so rapidly that it blows out my torch. Iron oxide is a very popular additive as well.

In relation to the perchlorates, if you want to go big consider making ammonium perchlorate hybrid fuel grains. For this you need AP, Al powder, Fe2O3 and an epoxy binder. I've been planning on giving this a shot for a while now but my biggest hold up has been making a GSLD anode for a perchlorate cell. Now that I have a good means for nitric acid, I can get to work on this, and then use it in a cell finally.

ecos - 27-4-2016 at 12:43

Quote: Originally posted by Chemist_Cup_Noodles  
So if you are going for a little farther than plain beginner mixtures, you could go for some chlorate or perchlorate mixtures. Some good examples are actually still close to the classic KNO3 and sugar mixes, but should have a much better energy density and specific impulse. I've been hunting down another similar thread I saw where this guy experimented heavily with these mixtures but can't find it.

If you want something very different, consider a mixture similar to the "zincoshine" used by Homer Hickam Jr of NASA and Bocket Boys fame. But instead of zinc powder aluminum powder should yield good, possibly better, results.

Also, try experimenting with different compounds to increase burn rate. I've found that sodium metabisulfite does really quite well in this manner. Sometimes when I try to light a slightly wet mass of it, it produces gas so rapidly that it blows out my torch. Iron oxide is a very popular additive as well.

In relation to the perchlorates, if you want to go big consider making ammonium perchlorate hybrid fuel grains. For this you need AP, Al powder, Fe2O3 and an epoxy binder. I've been planning on giving this a shot for a while now but my biggest hold up has been making a GSLD anode for a perchlorate cell. Now that I have a good means for nitric acid, I can get to work on this, and then use it in a cell finally.


you can buy PbO2 anode from here : www.ebay.de/itm/161891096215
it costs much but it will stay for long.

Herr Haber - 7-5-2016 at 06:08

Sugar... I'm gonna cry!
Try sorbitol and never go back to sugar even though it's more expensive.

With the low melting point of sorbitol you'll avoid the many problems encountered with sugar.
Sorbitol + KNO3 viscosity allows for almost perfect casting. No air bubbles and no schrinkage compared to regular sugar. I could continue my rant but I think I've written about it in other threads. Or talked about it IRL to so many people that I cant make the difference anymore :)

[Edited on 7-5-2016 by Herr Haber]

XeonTheMGPony - 7-5-2016 at 09:10

Look at the work don by one gent on you tube using Erythritol, KNO3 engine very nice and powerfull.

https://www.youtube.com/watch?v=Vj7ce1SFbow
https://www.youtube.com/watch?v=GgBwVxxqmKE < W/O annoying music

All so personally I used a top down ignition scheme with me engines with the bore dusted in ff grade BP, for fast full chamber ignition, not sure how that would work with his mix.


[Edited on 7-5-2016 by XeonTheMGPony]

[Edited on 7-5-2016 by XeonTheMGPony]