253 replies to this topic

[BrightStar]

...help needed please

Once dampened and allowed to dry, can dextrin bound riced BP simply be re-wetted to regranulate it, or does the dextrin undergo a one-way change and 'set' the first time this is done?

I've made a poor batch of BP testing a new method (the granules are too fine) and am wondering if I can save it.

Edited by BrightStar, 05 October 2006 - 11:41 PM.

[karlfoxman]

Dextrin can be re-wetted, this is why its not so good in damp climates. So yes you can re-wet your bp. Just so you know SGRS is the binder that is more difficult to re-wet.

[paul]

I did a burntime test for my CIA blackpowder.

1.07sec for 52cm distance. I?ll repeat that test several times to find the average burntime.

http://www.zippyvide...20006/untitled/

EDIT: It was almost 60cm for the 1.07sec...

I did two further tests: Both bp trains were 50cm long. The one took 0.84sec the other one 0.76sec.
I compared these values to the one from Dan Williams. He uses pressed and corned black powder with charcoal from a willow type tree.

You can see that my bp is much slower the pressed and corned type. (My average value with a third value is 1.6sec/100cm)
So the CIA bp burns at about 63cm/sec! Dan williams best value is 185cm/sec and the lowest 153cm/sec.


These values are ok I guess, I always used to use it with every device I make.

Edited by paul, 12 October 2006 - 12:19 PM.

[Stew]

Hey i milled up a batch of BP and it has a very slow burn rate. I used the ratio 75:15:10 and when i put it in a line to test it the burn rate was about 1sec for 10 cm. Whats going on?!

[Ritual33]

Sources of your chems, mill time etc?

Drew

[Stew]

milled for 3 hours. kno3 from a garden shop but willow charcoal and sulphur from ebay (dodgy i know but seem fine!).

[Ritual33]

I'd say it was the kno3, where did you buy it?

Drew

[Stew]

oh sorry forgot bought that off ebay aswell..sell sum dodgy stuff on there. i have made smoke bom*s with it and seems to work fine? confusing.

[Ritual33]

Ahh, thought maybe you had brought some general fertilizer stuff. What are you using to weigh the chemicals?

Drew

[Stew]

small digital scales. accurate to 0.01grams so i don't think that's the problem.

[pyromaniac303]

oh sorry forgot bought that off ebay aswell..sell sum dodgy stuff on there. i have made smoke bom*s with it and seems to work fine? confusing.

Impurities only seem to show thereselves when you want something to burn rapidly, or with a colour. Slow burning things like smokes can still work well with fire retardants mixed with them, you just get a slight burn rate change. (from my experience anyway)

[Stew]

hmm so just impure chemicals then?

[Caramanos2000]

Would this even work? http://cgi.ebay.com/...mMakeTrack=true

[portfire]

I dont think it's any good for BP but it has it's uses

http://www.pyrosocie...ivated charcoal

[paul]

It has no use for real black powder