Airfloat Balsa BP
#1
Posted 26 November 2010 - 10:30 AM
Just before I disappeared off the face of the earth a few years ago (actually got a job in london and spent my life living in crappy B&B's during the week, and in Central London they are crappy), I saw a thread about who could make the best BP for use in propelling a tennis ball the furtherest using a cannon.
I found this fantastic and after reading about Balsa Charcoal being the best I decided to make my own. Well I think I did too well as the stuff is SOO light I really am having issues weighing it.
When I made the first batch there seemed a hugely disproportionate amount of charcoal to Saltpetre and Sulfer. Anyway I continued and when actually trying it I was extremely disappointing (I used the basic mix rather than granulating it, as I'm still learning, and haven't got that far yet), well it was very slow and it was quite obvious that a lot of the charcoal hadn't burnt as there was a huge amount of residue left on the floor, and if anything the residue seemed larger than the original mix .
I'm using jewellers scales that are acurate to 0.1g and retried the mixes, but the same happened.
It there something fundemental that I'm doing wrong? or is my charcoal just too fine (if that is possible) ?
I have just received some willow charcoal and it is so much denser than my homemade stuff so I will retry the basics again this weekend with that.
I still have a huge amount of balsa powder left, it's stored in a glass jar and after shaking it briefly, it really does act like a liquid, interesting in it's own right but frustrating at the same time.
Farnet
Take time for example, have too much of it and you will eventually die....
#2
Posted 26 November 2010 - 10:58 AM
I am pround of my charcoal, but not how it reacts as a component, I do think I should have wet the mix and used dextrin, but this was 3 years ago, either way, I shouldn't have been left with such a huge amount of residue... and that is what bothers me.
BTW whatever happened to that thread, as it was a really good piece, and most people were rising to the challenge, as well as creating rules and measurement, I did learn a lot from it.
Take time for example, have too much of it and you will eventually die....
#3
Posted 26 November 2010 - 11:33 AM
#4
Posted 26 November 2010 - 11:45 AM
Are you mixing the BP in a ball mill ?
No, and I'm coming to the conclusion that it is probably my mixing, as I don't think that KN03 had bound properly to the charcoal. even with best intentions doing it manually was painstaking and ineffective....
Ohh well, as I mentioned in another post this morning, I should have the makings of a ball mill at home waiting for me tonight :-)
Take time for example, have too much of it and you will eventually die....
#5
Posted 26 November 2010 - 09:43 PM
Keep mannequins and watermelons away from fireworks..they always get hurt..
#6
Posted 27 November 2010 - 12:52 AM
I make Pawlownia charcoal and thought the same thing, it is so light and fluffy.
You need to use a ball mill, the stuff will be so fast it will scare you!!
Someone else said " the bigger the kilo(charcoal), the faster the powder will be
#7
Posted 27 November 2010 - 02:25 AM
#8
Posted 27 November 2010 - 12:59 PM
Went down to the shed to start setting up for the weekend and found that the entire inside is saturated, with water dripping off the electrics.
One dehumidifyer later, heyho.
I'm really looking forward to retrying those tests now I have a firmer knowledge of what I am trying to achieve. so watch this space.
Take time for example, have too much of it and you will eventually die....
#9
Posted 27 November 2010 - 04:22 PM
#10
Posted 27 November 2010 - 06:15 PM
#11
Posted 27 November 2010 - 08:36 PM
it sounds like his workshop is damp prone.
Paul.
2KNO3(s) + 3C(s) + S(s) -----> N2(g) + 3CO2(g) + K2S(s)
#12
Posted 27 November 2010 - 10:52 PM
I do think I wasn't hitting the target due to inexperience and being over excited at making my very own charcoal....sad I know but true.
As for the shed, well I have 1x60 litre/day and 1x28 litre/day dehumidifyers going (its an 18ft by 9ft shed) and things are starting to dry out, so I will be on track for next weekend, hoping I get the orders from inoxia and ebay on time.
Take time for example, have too much of it and you will eventually die....
#13
Posted 27 November 2010 - 11:02 PM
#14
Posted 28 November 2010 - 11:52 AM
I crushed it in a pestel and mortar, and mashed it to an extreme fine powder, I must admit I starting to change colour myself by the end of it and I literally had to hose myself down before being allowed back into the house.
overcooking, or allowing oxygen into the container would have spontaniously ignited the charcoal and the edges would have turned a grey colour so I am very confident that that didn't happen as I allowed to oven to go cold before I opened the lid.
Take time for example, have too much of it and you will eventually die....
#15
Posted 29 November 2010 - 09:16 PM
You will see a massive change in BP quality when you start using a ball mill with decent media. It grinds all the chems properly & mixes them well.
I used to make good 1" ID rockets with the chems ground by hand. When I got a ball mill with lead media I had loads of CATOs. I had to adjust my ratios, nozzle size & even tube strengths to get them to work again.
My normal BP (using BBQ charcoal) that I now use for lift is way faster then my hand mixed BP used to be with commercial A/F charcoal.
It all take lots of practice, many failures & then when you get it right, you think its so easy !!!
Phil.
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