Corning BP

[warthog]

This isn't a how to question, that I completely understand. What bothers me is the amount of extra work it seems to bring into things. The making of the BP pucks is where this makes me wonder. If I make 100 lb. or more batches of BP, then sit down and make all of this into pucks, at what appears to be a 1 at a time rate, I would be there all summer. Once the pucks are pressed though it moves right along, especially if the screening process is mechanized. I understand some, likely not all though, of the advantages that corning brings but the time input seems to outweigh these to me.

 

How about it then, anyone out there running a hammer mill and corning their BP? Could you tell me how you manage to make this work for you? Especially help me with the puck making, do you use something like a star plate maybe? Even then it would be slow though you could speed it up some with a pneumatic press rather than the hydraulic one most folks run.

 

Thanks for any input.

[marks265]

I used to corn bp but man what a waste of time. You may have read that this process is done for harder grains and meant partially for things like shipping and handling use and abuse. But if ya really want to give it a go then here's what I have done in the past.

 

I made a Sponenburg mill jar such as the ones in my blog. Then I drilled it full of holes and added billiard balls to the jar. I only drilled the holes in the pipe part, not through the fittings at each end. IIRC I also remember cutting the end pcs back for more exposure. I spun the jar on a ball mill frame with nothing under the rods except a catch container for the powder. I pressed my pucks less than 1/2" thick, broke them up and added them to the jar. As soon as I got done pressing the pucks, I corned them. You could tune the jar by drilling larger holes and lining with stainless screen. IIRC I made 3/16" holes and lined the jar with 10 mesh.

 

Have fun

Mark

[warthog]

Thanks but I am not wanting to do it. I more want to know how folks get over what you found, the manpower issues of making the pucks.

 

I am quite happy with my granulated BP for all my applications.

This is more wanting to know if there is a way to actually make corning work for an amateur.

[pyrogeorge]

I made some pressed pucks but the result was disappointing.I don't know why but it was slow burning and i had two failed shells.

I use only the 20# screen for granulating the BP.Much faster method and fast burning granules.

[Mumbles]

In some very unscientific tests I did a number of years ago I found that corned powder actually lifted an object higher. I'd like to retry it some day with better variable control. It was interesting to say the least however.

 

Given that this is a hobby of love, there is no reason that an amateur could not corn their own powder. The only additional cost is time spent if there is some reason you think it may be worth it. Time is generally not a factor for me. I some times think I am in the minority however valuing quality over quantity though. I've seen more than my fair share of crap thrown together.

 

Plenty of people go through the trouble of corning and grading their own powder, however I am not one of them. It does have a few advantages such as consistent bulk density for loading repetitive units via volume. It also is denser so may allow to squeeze a little extra break or lift into a given area. There is also something to be said for the pride of it. If they take the time to corn and grade their powder, just think of the care they put into the rest of the items. You don't see too many people who do that who make 40 crappy 3" dump break shells in a sitting. In my case, it's just not worth it. Any influence it may have in shells I tend to build is not very noticeable in my experience, so I stick with granulating. I also happen to get more of the size I use for lifting and breaking shells, and less fines by granulating. If you build a corning machine, corning BP may actually be less work in the long run than granulating.

[Algenco]

coat rice hulls, simple, quick, and with hot powder it works just as well as corning or ricing

 

I can do 25lb in 20 minutes and not break a sweat

[dan999ification]

i only ever corned my bp before i got a mill going in small 3-4g pucks using activated charcoal for artists=poor bp, standard granulated powder was just not lifting well enough, corning saw the same powder throw 3" shells [my first cans] as high as my now milled and granulated powder using the same percent by weight and better charcoal, again no scientific proof

i have found that it can improve the quality/power but if the bp is at the point of no returns you wont notice it too much, more for ease of handling,roman candles,firearms.

apart from the pride thing i have found no need to corn bp since milling it.

 

dan.

[warthog]

I would gladly corn my BP. I just can't get my mind around making pucks of all of it first before breaking it up.

 

I suppose one day, when I am more settled down and not so new to all of this I will give it a try at least.

 

 

I guess what I most wondered is answered, you make th pucks, one at a time. I thought that perhaps there was a way around that so that you could make them many at a time. That or some other way to speed up that particular part of the process since it seems the most labor intense.

[319]

I would gladly corn my BP. I just can't get my mind around making pucks of all of it first before breaking it up.

 

I suppose one day, when I am more settled down and not so new to all of this I will give it a try at least.

 

 

I guess what I most wondered is answered, you make th pucks, one at a time. I thought that perhaps there was a way around that so that you could make them many at a time. That or some other way to speed up that particular part of the process since it seems the most labor intense.

 

I make many 1/8"x4" pucks at a time by stacking Al discs between the powder before I press it.

 

 

Sam

[warthog]

I make many 1/8"x4" pucks at a time by stacking Al discs between the powder before I press it.

 

 

Sam

 

THAT was what I was looking for Sam! Thanks

[FREAKYDUTCHMEN]

I make many 1/8"x4" pucks at a time by stacking Al discs between the powder before I press it.

 

 

Sam

 

You can also use greyboard for this, cut some and you can use the same carton disks for a couple of times. I press between every increment of about 10 to 15mm. When the column is about 12cm high I press all the pucks right trough the cilinder.

 

It's not extra work, but knowing how the job should be done in the right way.

Edited March 14, 2012 by FREAKYDUTCHMEN

[Givat]

I made some kilos of corned BP a year ago, thought it will be better as lift and break.

I was really disappointed to find out that my granulated BP (2% dextrine) works better.

 

If you want you can PM, I think I can send you some pictures of the corning machine I made using my naskar roller as a base.

[Seymour]

I make many 1/8"x4" pucks at a time by stacking Al discs between the powder before I press it.

 

Plastic of the sort that ice cream comes in is also quite suitable for puck separation disks. You can often read the text from the product that's imprinted on the surface of the puck... small novelty.

[dagabu]

You can also use greyboard for this, cut some and you can use the same carton disks for a couple of times. I press between every increment of about 10 to 15mm. When the column is about 12cm high I press all the pucks right trough the cilinder.

 

It's not extra work, but knowing how the job should be done in the right way.

 

Yup, chipboard (same as your greyboard) disks allow the extra water to migrate out of the powder as well and since I cut my own disks, I already have them ready to go.

 

I do like the idea of the ice cream pails though. "Sorry dear, I have to buy more ice cream for pyro!"

 

-dag

[Potassiumchlorate]

My corned BP is pretty powerful, but maybe it should be even more so as granulated. I noticed that Triple Seven is granulated, though it's not really comparable, since that's a perchlorate powder for firearms.

[VintageRacer]

G,

 

I've made a few pucks just to get an idea, but did no real testing other than just burn it. I used a piece of aluminum thick wall pipe that was maybe 2.5" ID and maybe 6" long (I'm not there and don't merember) for my form or sleeve. For the separation/pressing disks, I used some 1/2" pieces of acrylic that I machined to the diameter I wanted, slip-fit or floating fit etc. I weigh my increment and add it to the tube then press them using just the ram on the 10-ton press. Very little moisture is needed.

 

Many ways to break the pucks after they are dry, and have that "ching" to them.... but why wait till they are dry? You can easily break them up right after pressing and you are not changing anything chemically in the pieces.

 

I'm pretty content with just "ricing" most of my fuel but I'll make pucks again one day. As with most everything else pyro, what goes around usually comes back in terms of interest.

 

 

DanB

[warthog]

I imagine one day I am sure to give this a go, it is just how I roll.

If I am able to finally move to FL so I can be with my family more (they a live there, I alone live elsewhere), I will do fireworking year round so will need to scale things up a bit I imagine.

 

Right now though, I am quite content ricing my BP through a #4 mesh screen and granulating it. I screen out the really fine stuff and if there is enough, I re-rice, if not I put it with the stuff I am going to put on my rice hulls. I rarely make batches of BP larger than 10 pounds, this when I am going to make hulls. Of course the stuff for hulls remains ungranulated, I usually have about 2 pounds of granulated BP for lift at a time. As I have said a number of times though, I keep things small here, just because I like it that way. Less book keeping.

Edited March 15, 2012 by warthog

[MrB]

I might be daft, but, why separate pucks that are pressed on top of each other with discs? If your able to put enough pressure on a stack of pucks, just dry-press em to a single solid chunk. Is there a reason not to? I've been shying away from the amount of labor so i have no experience with pressing, and crushing pucks, but as far as i can figure, stacking 200g of BP with 3 discs making it 4 pucks, and pressing, or just pressing one larger puck, either incremental, or in one go, it should be the same force required. I could see friction issues with the "one go" approach tho.

B!

[Potassiumchlorate]

Well, it's actually hard work to crush pucks manually. I'd actually rather go the other way and make them half the thickness I used to, "pre-crush" them a bit when they're still moist and then dry the pieces. Edited January 6, 2013 by Potassiumchlorate

[marks265]

MrB

 

The corning process is greatly optimized when the discs of compacted powder have a smaller mass than a larger mass. If you have one large cylinder of compacted material a lot more work is required to reduce it. Where as if you have much small cylinders the corning process goes much faster. Would you want to reduce one large boulder or a bunch of much smaller stones? Also the efficiency of the batch to produce the desired grain size will be increased because of the smaller amount of work in the corning process. Trying to reduce the "large boulder" will create more smaller particles than wanted per batch.

 

Mark

[MrB]

So it's just about the ease of the first crush after compressing the puck. Ok, then i'm with ya all. Curiosity, a funny thing. Thanks.

B!

[marks265]

So it's just about the ease of the first crush after compressing the puck.

 

Sounds like you missed the biggest point. It will be the difference of making 40 percent dust vs 20 percent dust for example. When you corn you want to maximize your process to get the most of the target grain size. I haven't corned any powder in years so I just through some numbers out there for an example to make my point.

 

Mark

[MrB]

The corning process is greatly optimized when the discs of compacted powder have a smaller mass than a larger mass. If you have one large cylinder of compacted material a lot more work is required to reduce it. Where as if you have much small cylinders the corning process goes much faster.

Ok, so this must have come in after i opened my response, so i didn't see this. So here goes. In my mind, if you got a 4 inch cylinder that your trying to compress in one go, or if you got 4 1 inch cylinders stacked on top of one and other, it just doesn't do any difference. Your still trying to compress the same overall cylinder with the same pressure going in to it. If it's a matter of going incremental, then it really doesn't matter, the stacked cylinders do soak up a little of the pressure, so in theory the last puck is slightly softer then the first one, but i'd say it's negligible.

 

Sounds like you missed the biggest point. It will be the difference of making 40 percent dust vs 20 percent dust for example. When you corn you want to maximize your process to get the most of the target grain size. I haven't corned any powder in years so I just through some numbers out there for an example to make my point.

Don't worry about the numbers, they are never reproducible for anyone else anyway. ;- ) As i said, i've never really tried, but the shattered rocket engines i've feed back in to a mil has had the same thing going for them all, very little powder came from the crack it self. Pressed that hard my experience is that BP simply shatters rather then crumble, meaning you'd just have to break it once or twice to get to pretty much the same starting-point as 4 separate pucks. On the other hand, as i said, no first hand experience, so if you say there is a substantial difference in the end result, i'm going to take your word for it.

B!

[Mumbles]

Thinner pucks break up easier. This is the real reason. There is no performance issues or anything. The first few impacts to coarsely break up the pucks can be less forceful. This does tend to decrease the amount of fine material you get, and goes a little easier on the arm. They dry faster too.

[mickyp]

I might be daft, but, why separate pucks that are pressed on top of each other with discs? If your able to put enough pressure on a stack of pucks, just dry-press em to a single solid chunk. Is there a reason not to? I've been shying away from the amount of labor so i have no experience with pressing, and crushing pucks, but as far as i can figure, stacking 200g of BP with 3 discs making it 4 pucks, and pressing, or just pressing one larger puck, either incremental, or in one go, it should be the same force required. I could see friction issues with the "one go" approach tho.

B!

Not done but just a thought if you have card spacers its a good place for some of the moisture to be squeezed into.

 

Does anyone in the uk know a source for dies for a press for making pucks??