18 replies to this topic

[whoof]

Malcom Smith , might be a good place to ask if anyone has contact, hes done a an awful lot of experiments.

Burning straw gives something similar , i wonder if its seeds or husks that do it.
Straw alone gives a lot of smoke though.

Grass seed maybe.

Edited by whoof, 26 March 2014 - 06:09 PM.

[sfxdan3]

Thanks for all your ideas and comments.

I've tried suggesting leylandii as the resins would like up really well. Unfortunately I've been overuled and we sticking with charcoal powder. It works ok, but only produces small embers and doesn't travel that far. They've also changed what they want. One person wants some floaty floaty bits and another person wants some embers that look like rocket burners.

Gonks - the space heater idea is good, I've fabricating a mock up version of it which works really well. The problem were having is balancing the burners with the correct flow of air. As you need to keep the chamber hot so it helps ignite the powder and then use the air to punch it out.

So at this point, as we kind of have the embers sorted were playing with different things to make some floaty burning embers. So the fun continues trying cotton wall, straw, saw dust anything we can think of coated in any flammable substance we can find

Thanks again

[sfxdan3]

We got it looking really good yesterday just using charcoal dust made from BBQ charcoal. We made a venturie system using a road compressor running at 120psi which was generating 80mph of suction through the venturie. We had a bit of fine tuning moving the air supply up and down the chamber to opternise the air flow without cooling the burnings down. And with the help of a scoop on the front we managed to get the embers to fly about 20-30 feet.

Now we need to try different ideas for floaty bits. I out forward the idea of impregnating different materials with nitrates. So just waiting for the ok on that test. We found burning a roll of paper in a metal bin gives a really good ash effect and if you agitate it a bit with an airline and have some other material (charcoal, dust, wood clippings) in the bottom you can get some floaty bits. But still look like floaty burning bits of ash and not floaty embers. We've got some rolls of paper soaked in diesel and smoke fluid trying to see why that gives us tomorrow.

One last question. Would there be much difference with using postassium nitrate aposed to sodium nitrate for this gag?

Thanks for all the ideas and help

[megabusa]

Sodium nitrate will give a much more orange effect than potassium nitrate.

 

However, it is very hygroscopic, so you have to keep it dry & sealed from moisture until ready to use. It is surprising how in a seemingly dry environment, sodium nitrate will turn damp.

 

I used to use it in my 3lb rocket motors instead of potassium nitrate because it lit up the sky with a huge orange tail !