Corning BP with limited supplies

[BasedAndRocketpilled]

I have been in this hobby for around a year now and have made quite a few successful rockets, including one with a horsetail heading. I am interested in moving on to arial shells, and was wondering if anybody had any tips for corning BP with minimal equipment/financial commitment, as I am operating under a *tight financial margin* at the moment due to the pandemic. I have previously used pulverone type powder, which was fine for rockets as it was compacted into casings regardless. Is hand ramming mill dust sufficient to make pucks for corning or is an arbor press an absolute requirement?

[Carbon796]

You don't need pucked and corned powder for aerial shells. Screen granulated BP works fine. I wouldn't waste the time/effort to hand ram pucks.

 

Granulated BP, is a component milled product. While polverone is a scratch mixed granulated product.

 

Commercial and/or pucked products will give a greater density fill than granulated. But "really" isn't necessary.

[Richtee]

You don't need pucked and corned powder for aerial shells. Screen granulated BP works fine. I wouldn't waste the time/effort to hand ram pucks.

 

 

I’d beg to differ. Especially in smaller diameters. But yes, it WILL work. I was using about 8-10 grams corned to launch 3” shells, and it would take up to 25 of the unpressed granulated to approach the performance. And it’s “dirtier” fouling the mortar pretty quickly. Minor issues. Like said you don’t “need” it. But... I’m picky.

[ChrisPer]

I have been in this hobby for around a year now and have made quite a few successful rockets, including one with a horsetail heading. I am interested in moving on to arial shells, and was wondering if anybody had any tips for corning BP with minimal equipment/financial commitment, as I am operating under a *tight financial margin* at the moment due to the pandemic. I have previously used pulverone type powder, which was fine for rockets as it was compacted into casings regardless. Is hand ramming mill dust sufficient to make pucks for corning or is an arbor press an absolute requirement?

Hand ramming will not give the 2500-3500 psi and wait time that seem to be keys to successful corning. A bit of thought and ingenuity though, and a smaller x-sectional area and you might do it anyway.

I am a beginner but I got a press like Skylighter's home-built one going for initially well under $100. $20 for a bottle jack from the classifieds (you could just scrounge one), two hardware shop threaded rods cut in half to make four (hard to scrounge but could substitute scrounged steel and welding) , and slabs of top and bottom steel scrounged off a verge rubbish collection. A friend had a drill bit big enough for the rods.

Then I made white pipe 50mm cylinder (free if you scrounge but I paid maybe $5) and used it to mold resin ($30 not cheap) and sand (2 cups free from building site) pistons.

If you look for a friend with a well equipped workshop, they may have a shop press you can use anyway for free, if you bring your own puck die. I found that friend with the drill bit had two, after the fact.

[Arthur]

Granulated powder is inferior, but it can be used with some care and usually increased quantities.

 

Having the time but not the cash is a frequent life experience, make a small press using a half ton arbour press and make a 0.25 inch tool with a drill into a scrap piece of steel and use a fat wire nail as the moving piece.

[justvisiting]

ChrisPer seems to be quite talented at budget pyro

 

Arthur, it seems like you are suggesting making black powder pellets one at a time, is that right?

 

Just an FYI, when I attempted to make good 1" diameter pucks with my 1 ton arbor press, I was only able to get a density of 1.5. The baby pucks didn't break up the way I wanted, like denser pucks would. It takes 3000-3500psi to make 1.7g/cc. pucks. It seems that a 1 ton arbor press could be used to make pucks up to 7/8" diameter, but it would be quite laborious.

 

A lot of folks use a slow flash booster shaken onto the granulated BP they use to burst small shells.

 

One benefit of pucked, corned powder is that it doesn't hit as hard as granulated powder when used for lift, so it's easier on the shells.

[BasedAndRocketpilled]

Thanks to all for the helpful responses. I do not have access to any kind of machine shop and Im far too inexperienced to create anything resembling flash (only metal I have is MgAl for parlon stars anyway) so it looks like Ill be sticking with granulated powder as lift. Hope to be posting some successful shells soon!

[Richtee]

 

 

One benefit of pucked, corned powder is that it doesn't hit as hard as granulated powder when used for lift, so it's easier on the shells.

Yeah, an issue I have with Benz. Anything hot in the shell and I have to “cushion” the payload. Lost a few tubes to that.

 

Fuck it. I ordered another cheap ball mill. I need my BP back. Praise the Lord!

[ChrisPer]

Thanks to all for the helpful responses. I do not have access to any kind of machine shop and Im far too inexperienced to create anything resembling flash (only metal I have is MgAl for parlon stars anyway) so it looks like Ill be sticking with granulated powder as lift. Hope to be posting some successful shells soon!

Sorry to hear that you feel so restricted. To me I have access to a garage not a machine shop! My friend has a bit more gear, true.

We have a movement here called Men's Sheds. They are local organisations of retired men and a few women, get hold of an empty shed or factory unit, and hang out there while doing stuff. As people retire they often move into smaller places, and pool equipment into their Mens Shed.

[SeaMonkey]

In the earlier days of Black Powder Manufacture the process of pressing was done at a relatively

low pressure of 400 to 500 pounds per square inch.

 

The pressing of the slightly moistened powder was done in stages of Press with Pressure for several

minutes, Release for a minute or two, then press again and repeat.

 

The Pressing Operation by this method of Press, Release, Press Again, was carried out for a minumum

of 45 Minutes for each batch. At the low pressures then available this process was found to be

necessary to attain the greatest possible density of finished powder.

 

If one does not have the equipment to press with the very high modern pressures, just take it slowly

for a longer period of time in order to achieve near the same result.

 

Hand Ramming can be done but, again, slowly over a longer period of time for maximum density.

Edited March 27, 2021 by SeaMonkey

[Arthur]

Yes! In these days of covid we each usually have time but no money, so simple cheap methods are IMO more accessible than time saving but expensive methods.

 

I know people with their own long travel 30 ton electro-hydraulic press, they can make lots of stars or lots of corned powder per minute, without the expensive press slow small scale work can still happen.

 

The gunpowder mill near me -long a museum- used to press incorporated powder on large square sheets of brass/bronze in huge stacks of alternating bronze sheet and powder several feet high the product being a slab of hard pressed material about 15" square and half a inch thick. These slabs were then pushed between rollers and the grains graded by mesh size. Reject powder was simply returned to the incorporating mill. -Reject was anything that they didn't have a need for at the time! The Hydraulics used water as fluid and took their power from a local stream.

[ChrisPer]

Those stacks of branze sheet and powder cake allow the press cycle to make many pucks.

 

THats what I do, but being in a white plastic pipe die I burst a screw adjustable hose clamp that was reinforcing it, so I cut back to three 5mm pucks in a pressing. Instead of sheet copper I use a thick plastic bag cut into disks.

[MadMat]

It is a lot easier to think of pressing your pucks to a density of 1.7 g/cc, than to think of the pressing force as most jacks/presses don't have a pressure guage. when I press my pucks I put a measured amount of milldust into my die and press until it hits the target thickness. You just need to know a little basic geometry about area and volume to do the calculations. Then a little experimenting with which premeasured amount works best and you have everything dialed in. As far as a press, I have posted before; I got two pieces of 8" channel iron from the local scrap yard. I suppose you could just as easily use 6". Then a trip to the hardware store for two 3/4" threaded rods and nuts. I cut the two threaded rods into four, drilled four holes at the corners of the channel iron and assembled. After adding a blast shield and a small bottle jack, it was done. It served me well for a number of years.

Edited March 27, 2021 by MadMat

[Arthur]

An adequate quantity of a reliable quality of BP in some appropriate grain grades is a primary requirement. IMO making good BP is a primary need for making good fireworks.

 

If you can't press a 3" diameter puck then press a half inch puck and lots of them. If you will not make good powder then you have to buy it and pounds of cannon/2FA /4FA etc may or may not be easily available or cheap. Powder 120 mesh and finer is great hot powder for rockets, and a lot less dusty than powder strait out of the mill.

[Mumbles]

It can probably be done with ramming, but in my experience having a press to make BP pucks is advantageous. You can ram comets, there's no real reason you can't ram pucks, but I don't think you'll achieve the same density. Comets are taller (generally) and will have a bit more to them to help keep them together in their somewhat fragile wet state. The real reason I believe pressing is better for something like pucks is really two fold. First, you can achieve a higher density. Off hand, I believe I got a density of about 1.4 g/cm3 by ramming. Secondly, and probably related, is that BP tends to relax or settle a bit. When pressing you can bump up the pressure, let it dwell, and keep pumping the pressure back up until it stabilizes. I believe this is part of what is behind being able to achieve higher densities.

 

You can actually get to densities higher than 1.7 as well. I've gotten them up to close to 2.0 if not a touch higher. I did some very unscientific tests many years ago, and of the various grades I tested, 1.7 performed the best. There was a subsequent decrease at higher densities. It's something I'd like to repeat some time now that I have a little better idea of what I'm doing and know more about it.

[Arthur]

Does anyone want to progress the idea of using a single automotive brake pedal/servo with a single caliper and piston as a means of making a reasonable pressure for some kinds of press tools to make powder and other components. get any vacuum for the servo from a repurposed fridge compressor.

 

I have a puck tool that someone made locally and marked for grams and a press to here mark so that by watching you can get a consistent puck density. I too have heard that 1.7 is an optimum density.

 

I've considered changing a flat puck mould for a dished puck mould thinking that a dished puck may corn more easily -any thoughts. Clearly corning is what gives size/grade of powder grains and having ways to tend towards each mesh cut would be superb.

[ChrisPer]

My inner Heath Robinson thinks that hydraulic brakes idea would be pretty cool. There are a few problems though. I can imagine it working like a champ, but then I ask questions like 'what is the effort to frame up a lever that presses the master cylinder at the right leverage? What is the ratio of piston area in master cylinder and slave cylinder? How do we build the puck die? How far can the slave cylinder press travel?

 

I think the Skylighter style press with hydraulic bottle jack would end up a LOT simpler to build, and more versatile.

 

But fridge compressor as a vacuum pump is a great thought! I am thinking could use an old compressor receiver tank, cut open with flanges welded on to make it into a vacuum chamber. Vacuum drying chamber? FREEZE DRYING? I tried this for saving wet books some years ago, using strong plastic bags with a fridge compressor to evacuate them and let the water vapour out of the books.

Edited March 30, 2021 by ChrisPer

[ChrisPer]

As for the domed puck die, yes, good idea. I too really want to improve the lump/fines ratio breaking up the pucks. Maybe a chevron or waffle shaped pressing die could work, or a press-based breaking die?

 

Skylighter talked about pre-breaking the moist pucks before dehydrating them. I am wondering if un-dried they might slice in a kitchen slicing banjo (Mandoline) or similar, and retain the full density.

 

I had one puck only 2-3 mm thick when I did my batch the other day. Still to break them and try my new ceramic coffee mill.

 

My first (useless) batch of powder reached 80% of the bulk density of Goex. I realised that I had narrower grain size ranges than commercial, and less uniform sizes would reduce the pore space; so would tumbling to polish the grains, by rounding the angular corners.

Edited March 30, 2021 by ChrisPer

[Richtee]

After all the silly posts and other stuff... I really enjoy seeing black powder back in the limelight.

 

I made some charcoal the other day. I’ll be back. It IS after all time honored and respectable.

[MadMat]

 

But fridge compressor as a vacuum pump is a great thought! I am thinking could use an old compressor receiver tank, cut open with flanges welded on to make it into a vacuum chamber. Vacuum drying chamber? FREEZE DRYING? I tried this for saving wet books some years ago, using strong plastic bags with a fridge compressor to evacuate them and let the water vapour out of the books.

I posted this very thought a couple years back! I have an old fridge compressor that I use for a vacuum pump for electronic and laser experiments. I also tried it out for drying stars. It worked, but not as well as I had hoped. You run into problems with a temperature drop when the water begins to evaporate.

Edited March 30, 2021 by MadMat

[ChrisPer]

I posted this very thought a couple years back! I have an old fridge compressor that I use for a vacuum pump for electronic and laser experiments. I also tried it out for drying stars. It worked, but not as well as I had hoped. You run into problems with a temperature drop when the water begins to evaporate.

Veeery eeeenteresting. I am intrigued by that temperature drop. That would explain why the commercial labs we use for rock samples all use drying cabinets rather than a vacuum to speed things up.

[justvisiting]

http://pyrobin.com/files/2%20inch%20black%20powder%20puck%20die%20set.JPG

 

I finally just posted the link, out of sheer frustration. I don't have any more time to figure out how to get pictures into posts. It seems like the function (or me) is broken. Lost everything I typed, now I have work to do. I'd love it if somebody smarter could make the picture happen for me.

Edited March 30, 2021 by Mumbles

[SharkWhisperer]

Right click on image on Pyrobin webpage, select "Copy Image"; rejoin thread; start new post or reply/edit, and simply right click and "paste" just like it was text you were copying/pasting. Or you can provide the link, which you did and works.

 

With odd file types, you might have to convert them to another format, but this jpeg file copied directly...

http://pyrobin.com/files/2%20inch%20black%20powder%20puck%20die%20set.JPG

 

I finally just posted the link, out of sheer frustration. I don't have any more time to figure out how to get pictures into posts. It seems like the function (or me) is broken. Lost everything I typed, now I have work to do. I'd love it if somebody smarter could make the picture happen for me.

http://pyrobin.com/files/2%20inch%20black%20powder%20puck%20die%20set.JPG

Edited March 30, 2021 by SharkWhisperer

[justvisiting]

http://pyrobin.com/files/thumbs/2%20inch%20black%20powder%20puck%20die%20set.JPG

Edited March 30, 2021 by justvisiting

[SharkWhisperer]

http://pyrobin.com/files/thumbs/2%20inch%20black%20powder%20puck%20die%20set.JPG

Good job! Almost. But you only saved the "thumbnail" image that can't be enlarged for a clear view of detail. The pic I pasted above is rather large, but shows what I think you intended it to in terms of detail.

 

No worries--image files can be tricky and annoying little bastards if you don't work with them regularly. But, between the two pix, I think you've gotten your point across

 

Take care, SW