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Posted

I've honestly only used 75/15/10. I have heard that the PGI lift works fine though. It slightly edges out the standard as far as lifting capability. I don't know why it works better, probably more gas production.

 

With the stoiciometric I have no idea how you'd get that formula. There are over 30 products in BP combustion. I am sure you could balance that out, but it'd be a pain in the ass. Theres a break down of the combustion products in COPAE, and possibly in the PGI Shooter's Guide you get when you take the shooter's certification course. I vaguely remember seeing it there. Theres a little pyro chemsitry section in the back.

 

Just out of curiosity, what is the stoichiometric formula you have?

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Posted
I have 74.64/C 13.51/S 11.85 as taken from the "Do it Yourself Gunpowder Cookbook" by Don McLean as stoichiometric.

Here is a link to another stoichiometric equation... http://home.att.net/~numericana/answer/chemistry.htm

Tell me what you think...

When making large quantities its a lot easier to just use the 75/15/10 formula, as the stoichiometric formula would be very tedious to get the exact amount

Posted

Well I'm using this for BP making(only good if making ~100-200gr:

Standard 75:15:10, pour everything in water(water just enought to dissolve KNO3) boil up, after boiling up, WARNING DO IT OUTSIDE fill in ~20-30% more acetone then water/BP, quickly mix it, and filter all with jeans like material (towel will do to if it's dense), squeeze acetone out, dry it up and smash to peaces(better before it absolutely dries up).

Anyone else tried to make BP in this way?

In my experience it's good for lifting stuff :)

  • 2 weeks later...
Posted
I can post pictures when I get back if anoyone is interested. Somewhere, I also have videos of 3' trough burn tests.

Can't say as anyone appeared interested, but in the grand fashion of telling people more that they care about...here goes anyway:

 

I conducted burn trough tests similar to Dan Creagan's and LadyKate's site: Charcoal Tests

 

I tried to produce comparable results, so 200g of meal were ball milled in a hobby mill for ~8 hours to approximate Lady Kate/Dan Cregan's test set-up. All were bound with 1.5%CMC milled with the greenmix. A 36" aluminum angle was mounted between two 2x4 sections and a 30" (2.5') length marked off. 12g of BP was poured evenly down the trough, lit and filmed with my digital camera at 60 fps. I counted frames in the uncompressed DV file before converting to 640x480 30fps wmv files for uploading.

 

I filmed but haven't included other batches: Pine charcoal bound with dextrin, mixes of DBSP and BP, etc.

 

I filmed three batches all with charcoal made in a 1gal retort:

http://www.apcforum.net/files/IMG_0026nSmalln.JPG

http://www.apcforum.net/files/IMG_0030nSmalln.JPG

 

 

 

1) Poplar charcoal BP damp pressed to 1.7g/cc, then granulated to -16mesh.

2) BP made from newspaper charcoal (free!) dampened un-pressed and granulated. (this was filmed a few weeks ago)

3) Same BP damp but pressed to 1.7g/cc, then granulated as #1. (same meal batch as #2)

 

Results:

Pressed Poplar BP: .902 sec.

Poplar BP

 

Newspaper BP pulverone: .867 sec

Newspaper BP

 

Pressed NP BP: .617 sec.

Pressed NP BP

 

.617 sec beats a good number of their test candidates, including one test of Elephant 2Fg and isn't much slower than Goex 2Fa at .55 sec. And I'm recycling as well... :D

Interestingly enough, the loose Poplar meal burned faster than the newspaper meal, but when pressed didn't perform as well. I need to try an unpressed batch.

Posted

What this displays is the ability of the clay binder in the newspaper charcoal to decrease the density and therefore increase the burn speed. Remember, burn speed isn't the only thing you look for in a good powder, gas generation is also extremely important.

 

A golf ball test or similar with equal amounts of powder by weight will give you an accurate test. Have the local muffler shop weld you up a 12" length of steel muffler tubing, ~1.75" dia. with an automotive freeze plug welded in the end.

Posted
I like your retort design! Very simplistic and effective!
Posted
snip...gas generation is also extremely important. 

I haven't done back to back tests with a standard lift charge and shell weight, yet. I actually made up some cat-litter filled 2" cannisters, but with so much snow on the ground, I'm not motivated to slog through the drifts for a test shoot. The cellulose based BP I make lofts my shells with 10% their weight in lift grains; I shot a 213g 3" cannister shell with 20g BP and it went 250-300 ft. so (at least from anecdotal evidence) I think gas output is ok.

 

The common theory is that fillers (clay, surfacing agents, etc) in newspaper make it less desirable to some, but I find it has a good place in general use. Our local paper, I believe, buys paper form a producer that uses considerable post-consumer content, so I'm not sure how much "junk" is in the paper anyways. One benefit, though - paper is quite dense and a one gallon batch makes easily 3x more charcoal than cooking wood.

 

I know the pressure increase generated in the mortar / shell can have a lot to do with burning speed as well - several posts on rec.pyrotechnics deal with DPSP / BP combinations that supposedly are "spooky fast" for lift. I tried some in standard burning tests and only got 1.88" sec from 75/25 Bullseye grains rolled with BP - evidently pressure is needed to take advantage of the gas generation properties of the SP.

Posted
I like your retort design! Very simplistic and effective!

The vent is the only thing that allows me to cook resiny pine (for TT and Chrys stars) in my backyard...tried it *once* without it and thought my neighbors would lynch me.

Posted
I like your retort design! Very simplistic and effective!

The vent is the only thing that allows me to cook resiny pine (for TT and Chrys stars) in my backyard...tried it *once* without it and thought my neighbors would lynch me.

I had to laugh at your last post qwezxc12. I have also had some rude comments from my neighbors about the obnoxious smell from my charcoal retort. I like to make coal from the dry cones of the local conifer trees ie. Douglas fir and Ponderosa pines. It looks like you have solved the problem with your retort design by burning the vented gases. I have some empty paint cans so I will build one and try it out. Great idea! I'm going to do some balsa next.

Posted

I just got a paint can, but i probably wont need the copper retort tube. BTW, how is it attached to the paint can lid? I think i know how it is attached, but i don't know all the technical terms to describe it clearly.

 

Like you flared the end of the copper tubing and put it in a brass flared copper tubing to male brass nipple adapter thing, then the male nipple goes through the lid and you have a brass nut or something. And 2 washers?

 

Whats a flaring tool look like? *Googles it*

Posted
I just got a paint can, but i probably wont need the copper retort tube. BTW, how is it attached to the paint can lid? I think i know how it is attached, but i don't know all the technical terms to describe it clearly.

 

Like you flared the end of the copper tubing and put it in a brass flared copper tubing to male brass nipple adapter thing, then the male nipple goes through the lid and you have a brass nut or something. And 2 washers?

 

Whats a flaring tool look like? *Googles it*

No flaring tool required:

 

All I did was use a 1/4" copper drain tubing and a 1/4" compression fitting adapter; it's got a 1/4" tube compression fitting on one side and is male threaded (5/16" maybe?) on the other side. I drilled out fender washers on both sides to support it passing through the thin metal of the paint can lid, and use brass jam nuts (from the lamp repair section) to secure it.

 

http://www.apcforum.net/files/IMG_0003nSmalln.JPG

 

http://www.apcforum.net/files/IMG_0009nSmalln.JPG

  • 4 weeks later...
Posted
Can I launch 1" shells with powdered BP? I hate granulating. I was planning on using 2g for lift. Also, could I get away with making the Bp with KCLO4 to avoid milling and use it as lift? My sulfur and Charcoal are airfloat.
Posted

Compression fittings... hmm ill have to look into that!

 

Thanks!

Posted

Caramanos:

 

As Mumbles suggested go ahead and make a fine "pulverone". It will also teach you another basic you will use. Meal powder is OK for some applications, but I believe it best to use granulated BP, it is in most characteristics better.

 

As for the KCLO4 instead of KNO3, it is a stonger oxidizer and may make a faster green mix if you found the right ratios, but why not just wait the little bit longer and mill it. It is obvious you are just trying to shortcut things, and if you are serious about this hobby, that is a VERY bad habit to develop.

 

What kind of shell are you launching?

Posted
I am launching 1" round plastic shells. So far ive filled them with flying fish, magnesium turnings or Bp stars. I have yet to try some flash in there, because I dont feel confident enough to do so. But this is my main goal, to use about .5g of flash in each one with some flying fish.
Posted
That burn's well, go ahead and granulate it. Should make it more powerful.
Posted
You should add 6% water to your mill when you mill it. It will double the speed.
Posted

Thanks qwezxc12!

 

I went down to a local hardware store and this really cool old guy helped me find all the stuff. I picked up some vinyl tubing and tee joints for a condenser for general chemistry projects. Then we got the compression fitting and the lamp pipe nipple and nuts. Then...

"So... building a still?"

"... maybe..." :ph34r:

"Haha, well this should work just fine."

 

I can't stress just how cool of an old guy this was. Anways, i got it all set up on my paint bucket pretty much just like you have it. AND now i have another idea on how to build part of my EtOH still when i get around to it.

Posted
I have read the adding water thing. I havnt seen any conclusive results of this. its like personal preference or something.
Posted
I slowed it down, seems it took about .4 seconds for the pile to burn, is that good?
Posted
How long do i let it dry if I used starch spray?
Posted
WOOOOT. I tried it, flew about 100' and went off. had a charge of .5g German Dark flash and some Bp stars, OMG finally! Will Post videos soon. Oh, I used 3g lift.

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