My homemade black powder

[Vettepilot]

Two more interesting info sources:

https://pyrosource.fandom.com/wiki/C...tability_Table

https://www.amateurpyro.com/forums/t...lity-charcoal/

Vettepilot

[longrange2]

How would the cotton bush go for making charcoal? Vic Aust.

[ofitg]

I'll have to cruise back through my research material, (and hope it wasn't on the computer that crashed, though I am fairly good about backing things up.)

As I recall, cooking at too high a temp cooked off too much of the volatiles, and made a weaker powder. Don't quote me on that though... I'll try to find where I read it.

Vettepilot

According to Ulrich Bretscher's website (now archived), charcoal should not be heated above 450 degrees Celsius -

https://web.archive.org/web/20170428.../charcoal.html

[Vettepilot]

As my fuzzy old brain fogs through this again, yeah, I seem to recall deciding 600 to 700 farenheit would be good numbers to use. I built up a large dutch oven with screw in vents and a barbeque thermometer to cook charcoal on my turkey fryer, but haven't gotten around to using it yet. Been way too busy the last year or two, and only just now getting back to my pet projects.

Vettepilot

[Eddie2002]

I think a regular wood coal fire which is what I use runs around 600 to 700 degrees Fahrenheit according to a quick search. Open flames are hotter with bright yellow coals running around 800 degrees Fahrenheit. I usually just start a fire in the burn barrel and drop my cookie tin retort down onto the coals when it's burned down. If the wood is still green the container gets put in the fire sooner or I add a piece of fire wood for a little more heat. I pull the cooker out about an 1/2 hour after the cooking off smoke stops flaming. Not very scientific but for the amount of BP I make it has worked well so far. I also shake the container to move the contents around during the cooking. Need a new cooker, the good old trusty cookie tin is developing pin holes and is getting ready to burn through.

[Vettepilot]

If I remember right from my studies a couple years ago, "undercooked" charcoal makes what they called "Brown Powder" that was experimented with right around the time smokeless came out. It was supposedly stronger than black powder. I don't know what the negatives to it's use might have been, though I would suspect it would be dirtier. (More tars.)

Vettepilot

[Nobade]

Since I don't seem to be able to figure out how to search just in this thread, I'll ask...Has anyone done a study to determine an optimal milling time for your powder? I realize there are a huge number of variables involved, but basically I'm wondering if you see a continued improvement in performance up to a point then no or very little change afterward? I just ran a batch for 21 hours and pressed it into pucks this morning so sometime after Christmas I'll grind up some and see how it does. I did take a bit of the meal out after two hours, make screened powder out of it, and lit it off after drying in the sun. It wasn't very impressive. Hopefully the real stuff works better.

[Eddie2002]

Nobade, I've been wondering about milling time also. I'm only making screened powder, not pressed pucks but would think that extended milling would affect the final product in both cases. With my screened I have to mill for about eight hours to achieve decent results with a small noticeable improvement when extended to twelve hours.
One thing I have noticed is that if I mill the powder for eight hours, screen it and dry it then remill it for another four hours there is a real noticeable increase in the powder, it's better than just milling for a straight twelve hours. I wonder if the potassium nitrate gets combined better with the charcoal particles because the green powder has been wetted for the first screening which allows the potassium nitrate to be adsorbed by the charcoal instead of being on it's surface. The second milling and screening evens out the mix even more for a more consistent burn.
Like you said there are a lot of variables involved and sometimes I feel like I'm trying to reinvent the wheel. LOL

[Vettepilot]

The most consistent thing I've read/encountered speaks to milling for 8 to 12 hours being the trick for best performance. However, I've also read that there is nothing to be gained by milling more than four hours.

Once again; too many variables. Did you start with ALL THREE ingredients milled/ground to airfloat first? How efficient is your milling?? What ratio of media to product? What media? What tumbler fill?
What size media? Trippers in the tumbler or not? What tumbler speed? Etc., etc., etc...

Vettepilot

[Nobade]

Exactly. There are so many variables it would take forever to isolate them all. In this case I just started it at 0900 on Saturday and turned it off at 0600 on Sunday since I woke up then. Should work, we'll see in a few weeks.

[Nobade]

Nobade, this may give you some info, if you're interested. They did some mill time tests, which seem to be pretty informative.
http://www.wichitabuggywhip.com/fire...oal_tests.html

Thanks, I had read that years ago and it was good to refresh my memory. Kind of what you would expect.

[Vettepilot]

Yes, me too. We're lucky to have lots of testing and info available via the pyro guys. Besides all the great info in this forum, there wouldn't be much BP info without them.

Vettepilot

[Vettepilot]

Well, I FINALLY got around to casting up my media for use in a large ball mill I am making. It was one of those things you keep putting off thinking it's going to be a major PITA. But once I got all set up and going, it wasn't really bad at all. I made a custom holder out of thick aluminum for the 1/2" x 1/2" pieces of copper tubing, that also acted as a heat sink to cool the bottoms of the media and prevent leakage.

It's impossible to pour all of them perfectly, with no overflow, splash, dribble, etc. (Ask me how I know...) So I'm going to put on some very good breathing protection, and dress these guys up on my belt sander. You could also just run them in your tumbler without meal, to clean them up/knock off any lead flash.

For those calculating, I used most of 2- 10' lengths of 1/2" copper pipe to make mine. I cranked down hard on my tubing cutter in order to curl the ends in to keep the lead in place.

I used about 23 lbs. of my precious wheel weight lead to make these. I hated to use my WW lead, but figured using a harder lead would help prevent the sharp edges of the tubing from gouging out lead while milling. Anyway, this made enough media to nearly half fill a milling jar that is 6" diameter by 9" long.

Hope this info helps someone. Past posts indicate this is excellent milling media, and I really believe it will be!!

[LAGS]

The nice thing is , Your lead is not gone.
You still have it if you ever need any more lead and aren't doing much tumbling.
I have been thinking about casting up some tumbler stuff out of Zinc Wheelweights since I don't use the Zinc for much else except casting drilling fixtures and soft vise jaws.

[Vettepilot]

Yeah, I had that thought once.... seemed like a hell of a good one too!

So I took all my out-sorted wheel weights, threw them in a cast iron pot, and set them to heating on my turkey fryer. I was working around the yard, doing other chores, and from time to time I would check on them. All the while thinking "MAN, ya gotta get that zinc really hot to melt!!" But I could see some melted zinc in the bottom, so I figured it was working, more or less.

It's really embarrassing, but I must have gone through 2 gallons of propane before I realized my mistake.... most of those "out-sorted" wheel weights turned out to be STEEL!!

I never once thought to check that! Joke's on me! That was early last summer, and I still laugh every time I think about it!!

Vettepilot

[Vettepilot]

One last note on my milling media. The bottoms filled right out to the edge of the copper tubing. But surface tension of the lead made the tops come out more rounded and not filled out all the way to the very edge of the tubing. Late in the game, I realized that if you just quickly but briefly touch your ladle to the surface of the lead you just poured, it breaks the surface tension and allows complete fill out.

Not that it really matters....

Vettepilot

[Vettepilot]

Yep! Or I will have. Shop drawings and calculations are done, and all the parts are rounded up. Now to just finish up some other niggling little projects/"must get done" things, and then get 'er built!

Vettepilot

[dondiego]

I don't believe that black powder will detonate from a gun shot. You would need a tracer!

[Vettepilot]

I don't either; not even with a tracer.

I've heard that black powder can be impact sensitive, but never seen it demonstrated. Why don't you try it and video it for us?

Vettepilot

[LynC2]

A few years ago I tried setting off BP and smokeless on the anvil of my Wilton vise by hitting them with a hammer. The BP did not go off but the smokeless did with a light blow. However shooting a container of BP may well ignite from the heat generated by the projectile passing through it.