Improve granulated r-candy mix with sulfur or perlite.

[MinamotoKobayashi]

Hello.

Since I have reached the maximum performance available for a granulated r-candy mix pressed at 5660 psi, I wish to try to improve it to lift heavy weights like 7" shells.

My best goal was a 6" shell for a total of 1,8 KG lifted like a plume, but I doubt that the same rocket can lift also a 7" shell.

I heard around the net that the r-candy compound can be improved adding sulfur or perlite.

Any user has experience about this mix? Which could be a correct percentage of sulfur or perlite to add to the r-candy mix?

Actually my granulated mix is so made:

 

65% sucrose;

35% KNO3 (without ACA);

+1 gram RIO;

+2 grams 400-1000 titanium sponge.

Edited October 14, 2018 by MinamotoKobayashi

[OldMarine]

NeighborJ has been experimenting with perlite in whistle fuels with good results. You may want to pick his brain some.

[dagabu]

Perlite is a fully oxidized non-flammable mineral. I have no idea how you would use it in R-Candy?

What does it do?

 

NeighborJ has been experimenting with perlite in whistle fuels with good results. You may want to pick his brain some.

[MinamotoKobayashi]

Yes I know about NeighborJ experiments with perlite.

Perlite contains micro-cavities that allow flames to propagate quickly inside the mix, but I do not know if it works with r-candy ..

[NeighborJ]

I can't say with 100% certainty that perlite will do what you want but i can say that it has drastically increased every rocket comp I've tried it in. Sugar fuel is not among the fuel I've tried, start with 10% perlite 8 mesh and see what happens. Add it after the fuel has been granulated and tumble the mix a bit before you measure out the increments to ensure it is evenly distributed.

 

I've been informed that there are variations of perlite and some types can be used in powdered form but i haven't had access to any form other than the stuff used in hydroponics.

[MinamotoKobayashi]

8 mesh grains are big grains! I think it will be difficult to mix well them with my 20 mesh granulated r-candy mix.

Also, 8 mesh is about 1/3 of the diameter of my nozzleless holes.

If two 8 mesh grains decided to exit at the same time, I predict a big CATO ...

[NeighborJ]

It is not structurally strong, it is easily crushed between your fingers. It will also get compressed into pockets of powder as the grain is pressed. It simply will not remain that large to cause a clog.

[MinamotoKobayashi]

I understand, but I fear that these pockets can cause pressure variations and spikes ...

[NeighborJ]

The idea is to cause numerous pressure spikes, so many in fact that it simulates a faster, even burn. You will need to use larger nozzles or just go nozzleless.

[dagabu]

Interesting stuff!

 

 

The idea is to cause numerous pressure spikes, so many in fact that it simulates a faster, even burn. You will need to use larger nozzles or just go nozzleless.

[GrassyKnollShooter]

KNO3 63%, SUGAR 27%, then sulphur 10%