DIY bp gurus: will I need to corn my black powder? for use in cartrides?

[Texantothecore]

My press die is 3"PVC.

Thanks. I just wanted to reconcile the numbers.

I am also looking at the twenty ton press which is another 70 bucks and it may be that I could go with a larger diameter puck. Or not.

[Texantothecore]

Cal50, applying 10370 pounds of force to 6.6 sq.in. of powder (inside a 3" PVC die) works out to 1570 psi.... it is clear that your system is capable of duplicating factory results.

Very sophisticated and well thought-out. Thanks for sharing!!!!!

Ofitg,

Can you do the math for a 6 ton press? Would it be adequate for generating say 1570 PSI?

Scratch that 6 ton press. It appears that it has only has two inches of travel and I would think that you would have to go through several pressings, inserting spacers after each compression. Let's keep it simple.

Thanks,
TTTC

[Texantothecore]

CAl50,
The first plate that you use to press down on the powder....is that just 1/4" steel plate? The one that is immediately below the ram?

Thanks

[cal50]

CAl50,
The first plate that you use to press down on the powder....is that just 1/4" steel plate? The one that is immediately below the ram?

Thanks

My block between the hydraulic press & the powder is just a round block of Delrin material. A bar end actually. You can use about anything that can survive the press pressure. I try to stick with alloy or plastic (non sparking) but for the press I doubt it makes any difference.

[Texantothecore]

Thanks for the info on the delrin round. That is really helpful.

There have been some real surprises in our discussion and that has been another.

[Texantothecore]

My block between the hydraulic press & the powder is just a round block of Delrin material. A bar end actually. You can use about anything that can survive the press pressure. I try to stick with alloy or plastic (non sparking) but for the press I doubt it makes any difference.

I will probably go with a 1/4" steel plate that will hold 36,000 PSI and I think it will work well. We in the South don't have much of a problem with static charges: I haven't seen one since I moved here 15 years ago. When I was young I lived in Wisconsin and the static charges with which I used to torture my sisters in the winter were like bolts of lightning.

[Texantothecore]

Sources for some of the stuff Cal50 is talking about:

Mcmaster-Carr

1. 0-10,000 PSI pressure gauge, liquid filled, pipe connection Brass NPT Male, 2 1/2 inch dial,numeric increments every 2,000 psi, +-1% accuracy in the gauge's midrange.

part number: 4053K15 $25.14 (bottom connection, others are available)

Mcmaster-Carr stresses that pressure gauges should be purchased which have a range that is 2x the range you will be working at as the cheaper gauges are accurate in the mid range, not so much in the low and high ends of the range. A more expensive gauge will be accurate througout the range but we aren't looking for that type of accuracy or price.

2. Delrin short rods, three inches in diameter, 1/2" thick(long), for the surface directly underneath the ram.

Part number: 8582K11 $5.47

Look at the listing of short rods in 3" diameter. They can be purchased to 6 inches long at a very reasonable price and can be sawn to size with a hacksaw. Might be some useful stuff in those rods.

After further reflection I am going to go with a Delrin short rod that is 1" long by 3" in diameter as I feel that it will be much stiffer and will transfer the pressure much more effectively.

Part Numer 8582K21. $9.56

[Texantothecore]

Cal50,

You stated earler that you released the clamps on the powder die and I was wondering how you clamp the die. Is this step critical?

[cal50]

Cal50,

You stated earler that you released the clamps on the powder die and I was wondering how you clamp the die. Is this step critical?

Not at all and I will dig it out and take some pics.
My 3"PVC is slotted completely down the side on my table saw. Hose clamps are placed around the outside and the clamp screws staggered for complete coverage /support for the pressed powder column.
It's only needed to tighten the clamps to support the area you are applying pressure to.

Once you are done pressing you loosen the clamps and slide your press cake out of the die. Some corn it now, others let it dry then corn it.
It might not appear flammable in this moist & pressed state but I assure you that it is.

[Texantothecore]

Not at all and I will dig it out and take some pics.
My 3"PVC is slotted completely down the side on my table saw. Hose clamps are placed around the outside and the clamp screws staggered for complete coverage /support for the pressed powder column.
It's only needed to tighten the clamps to support the area you are applying pressure to.

Once you are done pressing you loosen the clamps and slide your press cake out of the die. Some corn it now, others let it dry then corn it.
It might not appear flammable in this moist & pressed state but I assure you that it is.

I had never thought of corning it with 6% moisture in it but it seems to me that it might cut down on micro dust in the air which is the real safety issue with Black Powder. Many of you are not old enough to remember but when I was a kid charcoal factories blew up from the microdust in the air and even more common were explosions at wood working operations, grain mills, etc. OSHA came in and required some rather sophisticated dust recovery systems and those problems have disappeared.

I am suprised at your slit powder die and would never have guessed that particular technique would be used but it makes a lot of sense as removing the stacked pucks with a relaxed die would be substantially easier and less damaging to the pucks.

Pictures would really help us visualize your set up and its sophistication. Thanks.

[Texantothecore]

Cal50,

Can you describe the roller set up you have and how it works? I am curious about the distance between rollers and how it relates to grain size and it seems to me to be the best way to turn the puck into useful powder. Once you find out the initial settings it should stay about the same although I can see where it might change with large changes in ambient temperature.

Thanks

[Texantothecore]

Cal50, applying 10370 pounds of force to 6.6 sq.in. of powder (inside a 3" PVC die) works out to 1570 psi.... it is clear that your system is capable of duplicating factory results.

Very sophisticated and well thought-out. Thanks for sharing!!!!!

Ofitg,

Can you provide the formulae that you used for your calculations? I am particulary interested in the formulae that allow me to calculate the pressure in the cylinder of the press ad convert it to presure at the ram head as I intend to drill and tap the cylinder to install the pressure gauge so that I can repeat the pressure. I have tried to backwards engineer your calcs but I am missing something.

Update:

I found the calculation to use and was able to duplicate yours and Cal50's results perfectly. thanks for your help to both of you.

[cal50]

Some pics of my press die. This is a larger diameter one than the 3" I referenced earlier. I did some experimenting a while back and this is the one I have used the most and currently. Its PVC plastic pipe with a table saw cut down the side its entire length. I slip on standard hose clamps and tighten them down before use. I have a turned solid aluminum slug for my press block. Also pictured are aluminum spacers I cut from flat aluminum to place between my pressed powder pucks.

Basically I tighten the clamps and set my press die on a sold piece of aluminum for the base. I add moist powder into the die , spread it around to level it out , drop a aluminum spacer on top , add more powder , level it a bit, drop a spacer , repeat, repeat.

Once to the to of the clamp area I put it under the hydraulic press and crank up the pressure. I place a rag or paper towels around the bottom because the water you added will be seeping out the bottom and the rag catches it. I check every few minutes and add pressure until it holds constant on my gage then let it sit for around 20~30 minutes.
Once its "time" I release the press pressure , use my power screwdriver and release the hose clamp pressure and slide the aluminum press block and the pressed powder from the die. I separate the powder "pucks" and then weigh them on a scale and with a marker write the weight on the powder puck. I can monitor the drying process and can tell when its dry when the weight stabilizes. I have and old cooler filled with silica gel and I can put them inside to completely dry them if needed. My relative humidity in Ohio is around 40% in the basement so totally dry is lighter than weighing it in 40% relative humidity.

Once dry you can corn it by your favorite method.


Stagger the hose clamps to support the powder around the press area-



Aluminum spacers for in between powder in the die~



Aluminum press slug~



Press Die~

[cal50]

Powder / ball mill~

You want or need a decent ball mill to make good BP. I purchased a tumbler drum from an online shop and made my drive for it. I had several DC servo motors and speed controls so I made a frame with belt and drive wheels from a dead belt sander. I can adjust the speed and have it set around 50~60 RPM. Inside I have about 1/4 the volume with brass and bronze lapping balls and pieces. This is the part that does the powder milling and grinding. I do my milling in 3 steps. 1st load the KNO3 or potassium nitrate goes in and runs for 2 hours. I stop it and add the sulfur and run it for 2 hours. Last stop I add the charcoal that has already been milled and let it run for an hour.

[Nobade]

That's a good tip, I hadn't thought about a DC drive. Makes it easier than changing gearing. Keep an eye open for old treadmills that people are giving away or selling at yard sales. They have variable speed DC drives in them. They also work for refitting small lathes.

-Nobade

[Texantothecore]

Some pics of my press die. This is a larger diameter one than the 3" I referenced earlier. I did some experimenting a while back and this is the one I have used the most and currently. Its PVC plastic pipe with a table saw cut down the side its entire length. I slip on standard hose clamps and tighten them down before use. I have a turned solid aluminum slug for my press block. Also pictured are aluminum spacers I cut from flat aluminum to place between my pressed powder pucks.

Basically I tighten the clamps and set my press die on a sold piece of aluminum for the base. I add moist powder into the die , spread it around to level it out , drop a aluminum spacer on top , add more powder , level it a bit, drop a spacer , repeat, repeat.

Once to the to of the clamp area I put it under the hydraulic press and crank up the pressure. I place a rag or paper towels around the bottom because the water you added will be seeping out the bottom and the rag catches it. I check every few minutes and add pressure until it holds constant on my gage then let it sit for around 20~30 minutes.
Once its "time" I release the press pressure , use my power screwdriver and release the hose clamp pressure and slide the aluminum press block and the pressed powder from the die. I separate the powder "pucks" and then weigh them on a scale and with a marker write the weight on the powder puck. I can monitor the drying process and can tell when its dry when the weight stabilizes. I have and old cooler filled with silica gel and I can put them inside to completely dry them if needed. My relative humidity in Ohio is around 40% in the basement so totally dry is lighter than weighing it in 40% relative humidity.

Once dry you can corn it by your favorite method.


Stagger the hose clamps to support the powder around the press area-



Aluminum spacers for in between powder in the die~



Aluminum press slug~



Press Die~

Cal50,

Is that a 6" diameter die? It seems huge.

Thanks

[Texantothecore]

Cheap screening for corning:

Mcmaster-Carr (www.mcmaster.com)

Lightweight-Particle-Filtering Stainless Steel Wire Cloth, Size 12x12 inches in the most commonly used mesh sizes:

mesh size P/N
10 × 10 9238T52 $8.62
12 × 12 9238T24 $5.77
14 × 14 9238T53 $7.38
16 × 16 9238T25 $5.77
20 × 20 9238T29 $6.30
24 × 24 9238T42 $6.67
30 × 30 9238T44 $5.77
50 × 50 9238T45 $4.93

Mcmaster has no minimum order.

I have read a great deal about corning and the number of different size ranges quoted is amazing. I will say that Swiss grain size is smaller than Goex and that may explain the speed of the Swiss powder.

[Texantothecore]

That's a good tip, I hadn't thought about a DC drive. Makes it easier than changing gearing. Keep an eye open for old treadmills that people are giving away or selling at yard sales. They have variable speed DC drives in them. They also work for refitting small lathes.

-Nobade

Nobade,

Thanks for the tip. I am going to keep my eye out for one.

[Texantothecore]

Cal50
The wideangle lens fooled me. The pictures are great! What a set up.

Do you have a picture or 2 of your roller set up for crushing the pucks. And can you explain just how is it used in practice?

Thanks TTTC

[cal50]

Cal50
The wideangle lens fooled me. The pictures are great! What a set up.

Do you have a picture or 2 of your roller set up for crushing the pucks. And can you explain just how is it used in practice?

Thanks TTTC

No pics handy as the corning machine is at my friends house. He was using it last ( he makes good powder also).
The roller corning set up works well if your pressed pucks / powder discs are similar in size ( thickness) to run thru the rollers. This is where we experimented with pressed powder thickness of smaller diameter / fatter Vs larger diameter puck and thinner pressed powder. The thinner pressed powder was definitely faster and easier to corn over a thicker piece running it thru rollers.

Our corning mill looks similar to what is pictured below but with a hopper and crank attached-

http://www.homebrew-supplies.ca/viar...18&item_id=369

We made the rollers from knurled aluminum and are adjustable for width / thickness.