64 replies to this topic

[portfire]

Beat me to this one D, but yeah, basically what digger said....One thing though, why did you expect adding more SrCO3 would improve the colour?

[CCH Concepts]

i will try again then. i omitted the dextrin and used red gum with alcohol. will doing it this way make the star harder then?

i also read about wetting a star with acetone and this melts the parlon so it doubles up as a binder, has anyone tried this.

[CCH Concepts]

Beat me to this one D, but yeah, basically what digger said....One thing though, why did you expect adding more SrCO3 would improve the colour?

i didnt, but was i was going to be omitting the parlon i wanted to keep the ratio's as close as i could. but thinking now i guess this would have no effect as the parlon just intensifies the colour rather than taking part in the oxidiser/fuel reaction.

[Mumbles]

Using red gum as the binder will result in softer stars than if using dextrin. Omitting the chlorine donors will also probably not do much for the color. When your parlon arrives, you might be surprised at the difference it makes.

[CCH Concepts]

yer im really looking forward to trying the parlon.

I’m thinking one reason my BP might be poor is due to bad quality pot nitrate. I’m curious what the reason people not use pot perchlorate. I’m curious because I’m confident with the quality of my pot percholate and it would be a good test.

Edited by CCH Concepts, 28 August 2009 - 10:27 PM.

[pyromaniac303]

I’m thinking one reason my BP might be poor is due to bad quality pot nitrate. I’m curious what the reason people not use pot perchlorate. I’m curious because I’m confident with the quality of my pot percholate and it would be a good test.

It is inadvisable to try and make BP for lift using potassium perchlorate as it is greatly sensitised by sulfur, almost as much as potassium chlorate although perchlorate-sulfur mixtures are used occasionally. Such mixtures must be mixed in specific ways to avoid fuel and oxidiser contact until it can no longer be avoided - see here for a commonly used perchlorate burst comp. Also perchlorate mixtures have a greater coefficient of pressure, meaning that the power of the explosive increases dramatically with the amount of confinement. To use a perchlorate mixture as a bursting charge is fine (as in KP, benzolift etc.), as you want the pressure to reach breaking point inside the shell, but to use it as lift may result in a destroyed mortar.

A small pile of KP burst charge may burn slower than average BP on the ground, but once subject to confinement will make more of a shattering brisant explosion which is quite useless and dangerous when used as lift. Lift should develop its power over time to 'heave' the shell out of the mortar rather than trying to shoot it out in a millisecond.

Most problems with BP are with the charcoal. What type of charcoal are you using? You mentioned airfloat before but not what type of wood it was.

Edited by pyromaniac303, 28 August 2009 - 11:52 PM.

[seymour]

i didnt, but was i was going to be omitting the parlon i wanted to keep the ratio's as close as i could. but thinking now i guess this would have no effect as the parlon just intensifies the colour rather than taking part in the oxidiser/fuel reaction.

If I understand you correctly, you are saying that Parlon does not take part in the fuel/oxidiser reaction? I understand how you could believe this, as Parlon is commonly referred to as just a chlorine donor, but it is a fuel too. The molecular formula for the substance (if my memory is correct) is (C4H6Cl2)n, with n meaning that the group of elements in the brackets is repeated over and over again to form each long molecule of the polymer. Anyway, for each molecule of Chlorine, there is also two molecules of carbon, and three molecules of hydrogen, giving the parlon a significant fuel value, even though it does not burn at a high enough temperature to be a fuel on its own (not even for blue stars).

Additionally, Strontium carbonate decomposes endothermically, so it cools the flame. Therefore adding another 15% will have an impact, though as your tests have shown, it still does work.

i also read about wetting a star with acetone and this melts the parlon so it doubles up as a binder, has anyone tried this.

I have done this fairly regularly, and it can work very well, and especially in stars with a high parlon content, such as Emerald Green, the stars formed are very hard. While red gum is weaker as a binder, adding it will make it much nicer to handle, as it lessens to some degree, the stringy, sticky nature that parlon compositions display. However with compositions with quite low parlon contents, (which I would be wary off from the start, as high chlorine usually means good colour), I can not guarantee that they would be hard enough for my liking.

[CCH Concepts]

It is inadvisable to try and make BP for lift using potassium perchlorate as it is greatly sensitised by sulfur, almost as much as potassium chlorate although perchlorate-sulfur mixtures are used occasionally. Such mixtures must be mixed in specific ways to avoid fuel and oxidiser contact until it can no longer be avoided - see here for a commonly used perchlorate burst comp. Also perchlorate mixtures have a greater coefficient of pressure, meaning that the power of the explosive increases dramatically with the amount of confinement. To use a perchlorate mixture as a bursting charge is fine (as in KP, benzolift etc.), as you want the pressure to reach breaking point inside the shell, but to use it as lift may result in a destroyed mortar.

A small pile of KP burst charge may burn slower than average BP on the ground, but once subject to confinement will make more of a shattering brisant explosion which is quite useless and dangerous when used as lift. Lift should develop its power over time to 'heave' the shell out of the mortar rather than trying to shoot it out in a millisecond.

Most problems with BP are with the charcoal. What type of charcoal are you using? You mentioned airfloat before but not what type of wood it was.

I'm not sure what it was, i brought it off of a ebay seller. it was posted as pyro carbon, airfloat. but i didn't really know what i was looking for back then so i don't remember what type of wood it was.

[pyromaniac303]

I'm not sure what it was, i brought it off of a ebay seller. it was posted as pyro carbon, airfloat. but i didn't really know what i was looking for back then so i don't remember what type of wood it was.

OK, due to it being described as carbon the chances are that it was activated airfloat charcoal, which is absolutely useless for lift, though great in BP based metal fire dust stars, fountains, drivers for wheels etc. You really need to either charcoal some of your own wood, or buy some willow, alder, grapevine etc charcoal. Even pine will give you a useful increase in speed. I'd say theres a very good chance this will solve your problems.

I buy my charcoal from Phil (Willow Charcoal) at a reasonable price, as charcoaling is a messy process and the fumes given off are a great way to find out if your neighbour has any washing out or windows open! If you have quite a bit of space available though there are hundreds of posts on the forum about making charcoal.

[digger]

OK, due to it being described as carbon the chances are that it was activated airfloat charcoal, which is absolutely useless for lift, though great in BP based metal fire dust stars, fountains, drivers for wheels etc. You really need to either charcoal some of your own wood, or buy some willow, alder, grapevine etc charcoal. Even pine will give you a useful increase in speed. I'd say theres a very good chance this will solve your problems.

What basis do you have for this comment? Have you tried it?

I would say that powdered BBQ charcoal is the worst charcoal for lift from my experience.

Here is a video of meal powder made from activated charcoal Activated Charcoal BP. I think you will agree that it is perfectly acceptable for lift powder. It may not be quite as fast as willow based powder, but there is not a great deal in it.

I would personally say that most problems with BP are due to poor mill efficiencies.

P.S. Activated "Carbon" may be poor for BP especially if it has come from an oil based process rather than the hardwood route. This however this is very different stuff to activated charcoal.

Edited by digger, 30 August 2009 - 09:13 AM.

[Mortartube]

How fine is your Pot Nitrate when you start? I know you say you are milling it, but put it through a coffee grinder first (you need 2, one for oxides, one for fuels etc), the sieve it. It should be as fine as talcum powder. This greatly reduces milling time. If you don't have a sieve, you can cut out the bottom of an ice cream carton and use a piece of fine mesh womens tights. (do not use for anything other than pot nitrate). You can make another sieve for charcoal, but DO NOT put metal powders through it, owing to potential for static. And do it outside away from other chems.

You can make your own charcoal quite easily. I made some willow charcoal last year and the increase in speed was astounding. I made mine in a biscuit tin with two small holes in the lid and cooked it over a camping stove, although over a garden bonfire wold be better. When the smoke stops, take it from the fire/stove. Put a coin over each hole and cover it with dirt or sand. Leave it to cool then grind in the coffee mill and sieve to get airfloat.Sort out any uncooked bits for re cooking later. The cooked stuff should snap easily and be black to the centre, brown is not fully cooked.

You should see a marked difference in speed after milling.

One last note, to easily clean out your coffee grinder, add a small amount of cat litter to the mill and blitz to powder, then discard. Repeat as often as necessary until it's clean.

Edited by Mortartube, 30 August 2009 - 09:46 AM.

[CCH Concepts]

due to mess and time i think ill go for buying some. pyromaniac303 you mentioned phil? i would be interested in buying some charcoal from a tested source. have you got some contact details?

[cooperman435]

I persoanlly don see the point in milling anything prior to ball milling. Your mill should pulverise everything its self (its a mill).

I can use lumps of charcoal, caked peices of dried Nitrate, hard lumps of dextrin and sulphur chips and when the mill has run for 15 min its all fine powder already.

CCH if you follow the link in pyromaniac303's post you can buy stuff straight from the website.

[CCH Concepts]

i just ordered some igniter's from you, but when i tried the charcoal it wouldn't let me add it to my cart. the quantity was blank and not populating a price.