First time BP problem
#1
Posted 15 July 2010 - 02:54 PM
After years of wanting to get into pyro I've finally pulled my finger out and ordered the various bits I need to have a go at making my own BP as a first step.
I ordered all my chems from hobbychemicals.co.uk
For the first go I thought I'd make a very small amount, keeping it simple I measured out 7.5Gm of Potassium Nitrate, 1.5Gm Airfloat Willow Charcoal and 1Gm Sulphur. The chemicals are already very fine and not wanting to invest in a mill just yet I thought I'd give them a quick grind in a wooden pestle and mortar.
In hot anticipation I marched outside with my concoction formed a small little pile (not contained) and lit at arms length.
Then nothing.
Kept the flame close for a long time and had several reattempts still nothing.
Even if it were poorly mixed or not 100% accurate I was expecting a little whoosh or at least for it to combust!!
Very disappointed I was really hoping to get off to a better start.
What on earth am I doing wrong please?
Thanks muchly
#2
Posted 15 July 2010 - 03:02 PM
thegreenman
#3
Posted 15 July 2010 - 03:06 PM
#4
Posted 15 July 2010 - 03:44 PM
Jay
#5
Posted 15 July 2010 - 04:49 PM
#6
Posted 15 July 2010 - 06:40 PM
Would anyone care to test a small amount if I were to post some?
Or perhaps I should just order a fresh batch from Gardens direct and see if it makes a difference?
Thanks
#7
Posted 15 July 2010 - 07:36 PM
I tend to get my KNO3 of inoxia in coarse and that is fine.
Hope that helps,
#8
Posted 15 July 2010 - 07:54 PM
It does sound like your oxidiser is a bit suspect although green BP is not necessarily the easiest to light - so don't expect miracles. It does matter what sulphur and especially what charcoal you use
If you are in any doubt about the usefulness of a ball here is a little compilation I made a couple of weeks ago comparing milling times. I started with KNO3 that resembled table salt, sulphur and willow charcoal (all from forum members). I think the results speak for themselves. In the last sequence my hand is shaking because a 'test' just before had taken the hairs off my forearm. Another critical piece of advice - play safe
#9
Posted 15 July 2010 - 08:10 PM
i will then give you my verdict on the stuff you have, if you want to do this PM me i will send you the required details as i obviously aint posting my info on a live forum haha
#10
Posted 15 July 2010 - 11:18 PM
it should glow red with a slow slightly fizzing progress. good luck. by the way well milled/ ground B.P looks very like fresh cement. very fine absolutely flat and almost the same colour.
#11
Posted 24 July 2010 - 12:38 PM
This time I spent about 20 mins with the pestle and mortar! I was surprised to find my right arm hurting when usually it's very good at such prolonged action!!!
Was a little slow to light but then went up no problem! Feel really pleased!
Interestingly, I left the small piles of BP on the patio from my failed first batch. They have been out in the elements since my first post about 10 days ago. Given that they point blank refused to light I was amazed that a pile went up very spectacularly from the heat of my new batch next to it!
Probably more flames and heat from the old pile than my new freshly mixed batch! Was very surprised but also pleased. It left behind some red blobs which resembled melted plastic - any ideas?
I then lit one further pile of 'old stuff' that had been sat out in the rain and sun for 10 days or more and it went up even more spectacularly!
Feel very pleased and looking forward to taking my new hobby further.
Def going to invest in a ball mill!
Thanks!
#12
Posted 24 July 2010 - 01:18 PM
You may find compacted comps easier to ignite also, try rolling a 5 mm or so paper tube, about 20-50 mm long from a few turns of paper, then press or funnel and wire load comp into it until you have a filled it solidly. Stand it upright, say with a little blutack or by pressing it into a sand bucket, then cautiously light the powder surface at the tube end. By timing burns of identically loaded tubes you can make meaningful comparisons of your composition burn rates as your techniques improve. Burning piles is instructive to a point, but frequently misleading once sufficiently good incorporation is achieved (goes "poof", but you can no longer judge which poof is better).
Being able to make black match makes this a relatively safe and easy test, you can stand back and observe, video/time with stopwatch, etc. You should try to make good quality delay elements like black match or Chinese fuse ASAP, they do not require spectacular quality BP but milling will help. Of course if you can get commercial fuse, use that.
BTW: leaving piles of failed test comps around is a bad habit, at the very least wash them away with some water.
- johndee likes this
http://www.vk2zay.net/
#13
Posted 13 August 2010 - 08:20 PM
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