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

[Texantothecore]

Good technical info for making charcoal at this site -

http://www.musketeer.ch/blackpowder/charcoal.html

The finished charcoal will weigh roughly 20% as much as the wood you started off with.

The key is to get the wood temperature up to 350 C (660 F) and hold it there long enough for the conversion to take place. How hot does it get inside an electric lead-melting pot?

Have you used a melting pot to do this? And thanks for the link it is very instructive. I wonder where Cottonwood will fit in as it is very light.

[ofitg]

A couple years back I was using a small LEE pot. I set a steel disc "lid" on top to hold the heat in. It took about 45 minutes from start to finish, yielded roughly 3/4 ounce of charcoal per run.

[cal50]

CAl50,

How much pressure are you running? I am trying to figure out what house jack to use as well as whether the frame should be sistered 2x10s or steel. The use of resin in the production of the pressure plungers at Gunthorp leads me to believe that the pressure may not be that much.

I most likely will be using a cup of BP at a time as that seems to be a rational approach.

Sorry for the late reply....that work thing.

My press is the Harbor freight 12 ton shop press and its useful for a LOT of projects and repairs:

http://www.harborfreight.com/12-ton-...ess-33497.html


I installed a liquid filled pressure Gage that has a max reading of 5000 PSI. With the hydraulic jack pumped up to 5000 PSI on the gage that imparts a ram pressure of 10370 force or a little over 5 tons force ( 1 5/8" diameter cylinder in the jack). I compressed my powder at this force in my 3" PVC press die and continue to add pressure until there is no more compression loss and let it hold there for 30 minutes. Basically I am adding a cup of powder in my die seperated by a metal disc, another cup of powder then another disc, etc until I have around 4" total height of "pucks" pressed in my die. After the hold time I release the pressure, remove the clamps from the die and separate the powder pucks and let dry.

[Texantothecore]

Wow! That is a really nice set up. Capable of running some real volume on the odd Saturday.

I have two Bible study friends who shot my rifle during a guys Bible Study weekend and they are really interested in .45-70 black powder now. I think both of them would love to build a set up like this in one of their garages for our use.

Where did you get the hydraulic gauge? I am having a problem finding one that is for a reasonable price.

Any tricks of the trade to using the press?

And thanks for the info on the 30 minute dwell time. That is very helpful.

I love this place....

[Texantothecore]

Some dollar issues:

For those of you following along, the Harbor Freight 12 ton press is $129.00. Cheap. The shipping is somewhat expensive because of the weight but I don't know if this will apply to presses bought in the local store or not.
The 3" pvc pipe will run you about $15.00 at Lowes and you will only use a 5" section.

Update: The 12 ton jack is $129.00 if purchased at the store. This is looking like a go.

[Texantothecore]

Interesting research on Cottonwood:

It appears that Cottonwood's density and weight per cubic foot is identical to willow and alder. Could be some great powder coming out of this shop.

[ofitg]

Cal50, assuming you use Schedule 80 PVC pipe, your pucks are 2.9" diameter? If I'm doing the math correctly, the puck would have a frontal area of 6.6 sq.in.

According to one of my books (Chemistry of Powder & Explosives. by Tenney Davis) the big manufacturers compress their BP with pressure in the neighborhood of 1200 PSI.

[Nobade]

Interesting research on Cottonwood:

It appears that Cottonwood's density and weight per cubic foot is identical to willow and alder. Could be some great powder coming out of this shop.

I have some cottonwood but haven't made charcoal out of it yet. But according to Fly over on the muzzleloading room, it makes a very fast powder that fouls terribly in guns. It works great in fireworks where you don't care about fouling, but isn't too great for rifles.

-Nobade

[cal50]

I had the gauge that came off of something else. Larger gauges did not have the fine line increments and the gauge I used was free. I did drill & tap a hole in my jack to attach it. Some hydraulic jacks have a service port which you should be able to plumb one in easy.

[cal50]

Cal50, assuming you use Schedule 80 PVC pipe, your pucks are 2.9" diameter? If I'm doing the math correctly, the puck would have a frontal area of 6.6 sq.in.

According to one of my books (Chemistry of Powder & Explosives. by Tenney Davis) the big manufacturers compress their BP with pressure in the neighborhood of 1200 PSI.

1.7g/cc is the target density of the powder you are pressing.
For my die and the column of powder I was pressing I am getting excellent density. Its been a LONG time ago but I actually did the math.

Here is a good read-

http://www.creagan.net/fireworks/blackpowder2.html

Info on presses and jacks with gages-

http://www.skylighter.com/fireworks/...cket-press.asp



Cut / paste
1) Basically you can make the pucks (cylindrical pressed "cakes" of powder) every size and thickness you want, but:
- making very small diameter pucks it will take time to convert a whole batch into pucks, given the fact that one pressing can take from 15min to half an hour, due to the necessary dwell time.
- Larger pucks require higher pressing loads to be adaquately compressed, due to the higher friction.
- Thick pucks will take longer to dry
- I press 12cm diameter pucks 1cm thick, weight is about 120 grams each. I would not exceed the 15mm thickness.

[Texantothecore]

1.7g/cc is the target density of the powder you are pressing.
For my die and the column of powder I was pressing I am getting excellent density. Its been a LONG time ago but I actually did the math.

Here is a good read-

http://www.creagan.net/fireworks/blackpowder2.html

Info on presses and jacks with gages-

http://www.skylighter.com/fireworks/...cket-press.asp



Cut / paste
1) Basically you can make the pucks (cylindrical pressed "cakes" of powder) every size and thickness you want, but:
- making very small diameter pucks it will take time to convert a whole batch into pucks, given the fact that one pressing can take from 15min to half an hour, due to the necessary dwell time.
- Larger pucks require higher pressing loads to be adaquately compressed, due to the higher friction.
- Thick pucks will take longer to dry
- I press 12cm diameter pucks 1cm thick, weight is about 120 grams each. I would not exceed the 15mm thickness.

Thanks Cal50 that is just the type of info that I am looking for.

New question: Assuming my goal is FFg, how much yield would I get from the shattering of a puck and sifting through a screen?

Would there by any value to pushing larger pieces through the screen and resizing them to FFg? Or would I just end up with more dust.

Would dextrin increase the immediate yield of FFg and cut down on the dust?

Thanks.

[Texantothecore]

Are the plates that you use between the charges of powder 1/2 inch?

That would give a 4 inch column.

How big is the base plate you use to support the powder die?

[ofitg]

1.7g/cc is the target density of the powder you are pressing.
For my die and the column of powder I was pressing I am getting excellent density. Its been a LONG time ago but I actually did the math.

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!!!!!

[Texantothecore]

I had the gauge that came off of something else. Larger gauges did not have the fine line increments and the gauge I used was free. I did drill & tap a hole in my jack to attach it. Some hydraulic jacks have a service port which you should be able to plumb one in easy.

I found a 0-10,000 pound liquid filled gauge at McMaster-Carr for $42.00 and it would seem to me a very good buy for the press.

Scratch that. Mcmaster-Carr has a liquid filled gauge, 0-15,000, for 25.00. It is for use with hydraulic oil. That is the one I was looking for.

[cal50]

Thanks Cal50 that is just the type of info that I am looking for.

New question: Assuming my goal is FFa, how much yield would I get from the shattering of a puck and sifting through a screen?

Would there by any value to pushing larger pieces through the screen and resizing them to FFa? Or would I just end up with more dust.

Would dextrin increase the immediate yield of FFa and cut down on the dust?

Thanks.

The corning process really produces all grain sizes and is hard to control for specific grain size. Some break the pressed powder with a wood bat or mallet then run through your screen or sieve. I used a roller set up like a flour or grain mill and adjusted the roller spacing to tweak grain size. If you have large grains like cannon or F you can re-run but you still get "corning dust" which is 5F and great flash pan dust.
Pressed powder needs no binder as Dextrin. It will only slow the burn rate and not help grain size IMHO.

[cal50]

Are the plates that you use between the charges of powder 1/2 inch?

That would give a 4 inch column.

How big is the base plate you use to support the powder die?

Mine are thin like the plastic separators used in a hamburger press. You can use tinfoil but I like thin plastic. The pressed powder pucks separate easily with some divider used. I put one in the press die before I add any powder, add a cup, add divider, add a cup of powder, repeat till I reach the top of the die.
Then I press the entire column.

[cal50]

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!!!!!

I know I am a little higher on compression PSI but I am close and a little more on the dense side (LOL!).

I did a comparison with Goex in the same granulation in a volumetric cylinder and weighed the same volume and I am damn close.
For performance testing I used a 3" PVC pipe section filled with dirt and two caps welded on. I fired it from a mortar straight up and recorded the flight time for a weighted dummy shell. My powder was noticeable faster / hotter and added a full 4.8 seconds to the total flight time from ignition to the shell impacting the ground.

[Texantothecore]

1.7g/cc is the target density of the powder you are pressing.
For my die and the column of powder I was pressing I am getting excellent density. Its been a LONG time ago but I actually did the math.

Here is a good read-

http://www.creagan.net/fireworks/blackpowder2.html

Info on presses and jacks with gages-

http://www.skylighter.com/fireworks/...cket-press.asp



Cut / paste
1) Basically you can make the pucks (cylindrical pressed "cakes" of powder) every size and thickness you want, but:
- making very small diameter pucks it will take time to convert a whole batch into pucks, given the fact that one pressing can take from 15min to half an hour, due to the necessary dwell time.
- Larger pucks require higher pressing loads to be adaquately compressed, due to the higher friction.
- Thick pucks will take longer to dry
- I press 12cm diameter pucks 1cm thick, weight is about 120 grams each. I would not exceed the 15mm thickness.

CAl50:

Just checking numbers here
You stated 12 centimeter pucks which would be 4.7 inches in diameter. Are you using a 5 inch PVC pressing die?

[LIMPINGJ]

Has anyone used Birtch to make powder with? Looking at the fireworks links it seem to be fast but how dirty compared to Willow is it? I have both woods on my place and was just wondering about how Birtch would work?

[cal50]

CAl50:

Just checking numbers here
You stated 12 centimeter pucks which would be 4.7 inches in diameter. Are you using a 5 inch PVC pressing die?

My press die is 3"PVC.