129 replies to this topic

[adamw]

If I recall correctly what I read, cocoa powder was once banned because it was so sensitive. Take that as a caution.

[BigG]

Cocoa powder does not refer to the actual material ?Cocoa Powder?, but to Black powder that uses Rye-Straw charcoal.

The reason for the name comes from the colour of the final mix and also to the crystalline shape of the finished material ? both resemble cocoa powder.

References are available from Davis, and from Lancaster, 3rd edition, pages 101-103.

[cat]

If I?m not mistaken, cocoa powder tends to be sensitive not because of the materials but the process of cooking the charcoal? My understanding was that pyrophoric oils retained by partially cooking rye straw where found to be the culprit?

Googled a few links, here is one by donald j haarmann:
http://groups-beta.g...08e73cf99d9cb4e

[broadsword]

Jus a quick question:
I made some black match 2day out of some 24hr milled BP. Will this fuse be any good or not? Because my thought is that its going to burn far to quickly. And for some reason it hasent coated the sting quite as librally as usual

[al93535]

I have a question for you guys. When making colored flames I have used sucrose/sugar to test for the color. I see that red gum, and other fuels are used in star compositions. My questions is, can't you just use sugar as fuel in stars? I know it is slightly hydroscopic, so if they were dried well, then stored the shell in a dessicant filled box wouldn't they be just fine to use? Or is there something else I am missing here? Thanks,

[Sprengman]

broadsword i dont know how fast quick is in your eyes. It will burn faster than Visco and slower than quickmatch.


al93535, no.

Sugar is a very bad fuel in coloured flame compositions. Its necessary to get the flame as hot as possible to obtain good colours, excepting blue flames. Sugar burns with a low temperature so the colour wouldnt be good. Only blue burning mixtures have to burn at low temperatures.

The best fuel for all other flames is a metalic one.

[al93535]

So Sprengman, Wouldn't it then be ideal to use it for blue stars? And an aluminum powder with sugar in green and red?

[Jerronimo]

Thats not true sprengman,

Sugar works fine in red star compositions.
Try this one if you have the chems:

SrCO3--------30
Sugar---------20
KClO3--------50

You could try to replace the sugar with (malto)dextrin

This should give a decent red

[al93535]

Yup I have already done that, I used 70% kclo4 and 30% sugar, the added 8% stco3 and it made a wonderful bright red. But I want to know if its okay to use it in stars? And with blues. Has anyone done that?

[adamw]

Well if it will form into stars then yes it can be used. They should take fire quite easily too. 'Sugar' of a sort is used especially for blues in some compositions. Lactose ('Milk Sugar') is used for this.

[al93535]

Thank you so much Adam. Lactose huh? Is it hydroscopic like sucrose, less or more?

[broadsword]

this may seem an odd question but here goes:
In many compositions it has different mesh types of charcoal, if you say have a comp that says you need 150mesh and 30mesh you dont add it to the meal powder when it is in the ball mill do you, because surely that would break it up into fine mesh?

[Pretty green flames]

i think the best option here would be to screen the charcoal in.

[BigG]

this may seem an odd question but here goes:
In many compositions it has different mesh types of charcoal, if you say have a comp that says you need 150mesh and 30mesh you dont add it to the meal powder when it is in the ball mill do you, because surely that would break it up into fine mesh?

Correct.

As this is a beginners thread ? I should point out that that published formulas are good starting points ? but as in many cases the exact method of mixing is not mentioned, results will vary. I suggest manipulating those starting points to fit best your methods.

For example: Lancaster gives the formula:

KNO3 (150 mesh): 72
S: 8
Charcoal Mesh 40/100: 16
Charcoal Mesh 28: 4

Many members might be wondering how the suppose the mix this! Well, Lancaster just screens it together a good 6 to 7 times ? producing a slow burning but well balanced orange fountain for a bigger diameter fountains. Putting the whole components into a ball mill will break down the Charcoal to a much finer partials, giving a fast fountain which lacks good sparks and is generally not interesting.

Mind you, Lancaster probably has an excellent quality finely powdered KNO3 and S to start with! Periled KNO3 will need to milled on it?s own for this formula to work ? otherwise, your final product might burn very poorly!

Also ? after mixing ? you might find the formula still too slow ? again, to do with the quality of the starting ingredients. Maybe a better option will be to substitute some of the C mesh 40/100 with airfloat ? ball mill it together with the KNO3 and S, and then mix in the rest of the charcoal?

[broadsword]

Last Night i made a fountain with iron powder and aluminium powder.
I had 3 parts Bp to 1 part iron powder in the frist fountain and that went fine.
But then on the larger fountain i did pretty much the same 3 to 1 mix with aluminium powder. I layered the mixes up so that it went (from the bottom) Iron, aluminium, iron, aluminium. and then just befor the clay choke i had some plain BP.

It was certainly a good fountain with an amazing start! but afer it had cooled on close inspection it had LOADS of slag around the top of the choke?

I wasnt sure why this was because there wasn't any on the first fountain.
Any thoughts?