28 replies to this topic

[TCblastmaster]

I have had some very good results with the CIA method but usually ball mill the C and S beforehand- otherwise you get solid lumps of sulphur in the finished product. However, using the CIA method and then ball milling the dried granules produces a much faster powder. Never compared it to the purely ball milled variety because one tends to stick with what has previously worked well.

In my experience the effectiveness of the CIA method depends on a number of things; ensuring that just enough water is present to keep all the KNO3 in solution prior to adding the alcohol - difficult when so much of the water evaporates during heating large batches safely and a large proportion may no longer be in solution (showing up as large crystals on drying and poor performance)and adding the correct amount of chilled alcohol to rapidly and completely precipitate the KNO3 -some of which could be lost when wringing out the ball of BP if too much water has been added or too little alcohol. Clearly the proportions of chemicals in the composition can change in many ways. Get it spot on and you'll have good lift powder with rather delicate grains (when grated through a screen). I have also found the lift made by this method to be very hygroscopic- what starts off as brilliant lift can be rendered useless by atmospheric moisture- purely anecdotal but I have experienced it, much to my embarrassment.

Ball milling is therefore essential, whatever method you use. Producing excellent BP is the Holy Grail of pyro and often a closely guarded secret.

TC

[CCH Concepts]

A bit like your spelling. I assume you meant launches and not lunches, hence the ham sandwich comment.

lol, im using the spell checker now, guess i missed that one sorry.

[CCH Concepts]

well the quality of my bp is coming along in leaps and bounds. hopefully i can keep this up and produce something close to what has been talked about. something i was interested in, was getting some sort of force gauge, that i could attached to a plug in a tube and make a rig for testing the force my BP is producing. i could then get quantitative results to test the quality.

with this i could calculated the estimated height for a given load and amount of BP. have any of you tried this.

i can see the obvious safety obstacles with this, not least making sure the gases have a safe route to take after pushing the plug/gauge. but is this something that has been done?

[digger]

well the quality of my bp is coming along in leaps and bounds. hopefully i can keep this up and produce something close to what has been talked about. something i was interested in, was getting some sort of force gauge, that i could attached to a plug in a tube and make a rig for testing the force my BP is producing. i could then get quantitative results to test the quality.

with this i could calculated the estimated height for a given load and amount of BP. have any of you tried this.

i can see the obvious safety obstacles with this, not least making sure the gases have a safe route to take after pushing the plug/gauge. but is this something that has been done?

There are far easier and safer ways of assessing deflagration speed. Think of a long v shaped channel maybe 5mm wide and 5mm deep and 1 meter long filled with your powder, simply fill the channel with your powder fuse it up and set the video running. You can then work out how long it takes for the powder to burn from one end of the channel to the other.

There is a great site out there somewhere detailing this method with results from all sorts of black powders from commercial to CIA and every charcoal type in between.

Read the following page thoroughly as there is a great deal of information here CLICK ME

Edited by digger, 08 September 2009 - 07:59 PM.

[CCH Concepts]

that was very interesting. has anyone tried the 68/22/10 mix. ive only tried 75/15/10. how have people found the difference?

[MDH]

Typically I would recommend these slower mixtures for rockets. While with fast powders such as willow or paulownia you will still accomplish great heights - and perhaps it's economic that you use more charcoal and sulfur - but 74/14/12 or 75/15/10 have been tested and shown to be optimal ratio sets for lifting off shells.

[seymour]

At a guess I would say that the 68/22/10 mix was specifically used as a propellant in guns, where the confinement of a metal tube and a well wadded projectile would allow it to burn fast, while the extra gasses produced by the fuel burning to carbon monoxide instead of dioxide would have, at least in the head of the manufacturer, have made it better.

Or if this is a formula from back in the days of importing nitrates or making them in rather unhygienic ways, it could just be to save nitrate.

[CCH Concepts]

one thing i have been looking at is a roman candels. good use for my BP without being to big or dangerous yet. what would you guys suggest as a delay charge.

from what i have read on wikipedia (book of lie i know lol) pressed meal powder or pot perchloate and anatomy trisulphide. would be pissbile with the chems i have. what do you guys use?

[Arthur Brown]

Candles are not easy to get right! Also there are three distinct methods of manufacture which you should research before you start. Candles by the old English method rely totally on having the right grades and speeds of BP available and very carefully weighed out. The old candles were entirely operated by BP, once started they fired at a rate according to the grade and grain size of the comp.

Edited by Arthur Brown, 10 September 2009 - 05:22 PM.

[CCH Concepts]

the method i used was to have some granulated bp followed a perforated end cap, followed by stars and BP pressed and this repeated several times.

but i don't get consistant results. any advice?

[Arthur Brown]

Months of clean handed research! Read every detail in lots of books and www articles.

[CCH Concepts]

i have googled but not found alto. any tips of refining my search. any names for methods etc?

[seymour]

This should get you off to a good start

http://blog.skylight...an-candles.html

Note that that is just one rather exotic method of manufacture, but you sahould get some good keywords for contuinued research

Edited by seymour, 12 September 2009 - 02:38 AM.

[CCH Concepts]

Funny enough i found that page last night. Im thinking of trying it next weekend. Or would you say there are easier methods?