Thought for pressing powder

[John McCorkle]

So question gents.

I'm hoping to start my hand at making bp...have been following the MASSIVE thread going for a while - all the while trying to catch up on older posts but it's thousands of posts long by now....it'll take me a while

I shoot mostly rifle but hope to get into pistol at some point. This means pressing powder.

I currently don't have a shop press....and if I got one it would be only for this use. Still may be worth it in the end but.....it got me thinking about alternative ways to apply the right amount of pressure to powder in a press die to get compression.

Is is possible to have a die made that would have a smaller diameter but longer length to use the compound force of a heavy bench vice instead? You'd end up with much smaller pucks and it would be very much more time consuming....but...doable? Is th juice worth the squeeze or should I just buy a press and find a place for it?



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[country gent]

Dont know if it would work or not but look at sinclairs benchrest reloading presses. they are a lever design and would be hard to make one up from metal or wood.

A wood working vise that mounts under the bench would have larger jaw area to work with, And some have quick acting screws making them easier to adjust.

Used arbor presses can be found fairly reasonable from 1 ton to oh my good.

A simple screw press could be made from pipe and threaded rod.

[Eddie2002]

Just crunching numbers shows that a 1/2 inch diameter hole is .19 square inches of area so a one ton press will give close to what's recommended for proper compression. The surface area is about one fifth of a square inch so one ton of pressure would give a full five tons of pressure. It would be pretty easy to set up as long as you have a block of aluminum to drill a 1/2 inch hole through, a 1/2 inch bolt or piece of round stock would work well for a ram and to close off the other end just tap it and screw a bolt in. I would think the "puck" would turn out looking like a short 1/2 inch in diameter pencil or a battery depending on how long the puck maker is. Think I have some 1 inch OD aluminum tubing with 1/4 inch wall out in the shop which should have a 1/2 ID. I'll give it a try and block off one end with a 1/2 inch plug and use some 1/2 inch rod as a plunger. Pretty sure I have a vice big enough to do the job also. Give me a day or so to sort it out.
Great idea by the way.

[John McCorkle]

Just crunching numbers shows that a 1/2 inch diameter hole is .19 square inches of area so a one ton press will give close to what's recommended for proper compression. The surface area is about one fifth of a square inch so one ton of pressure would give a full five tons of pressure. It would be pretty easy to set up as long as you have a block of aluminum to drill a 1/2 inch hole through, a 1/2 inch bolt or piece of round stock would work well for a ram and to close off the other end just tap it and screw a bolt in. I would think the "puck" would turn out looking like a short 1/2 inch in diameter pencil or a battery depending on how long the puck maker is. Think I have some 1 inch OD aluminum tubing with 1/4 inch wall out in the shop which should have a 1/2 ID. I'll give it a try and block off one end with a 1/2 inch plug and use some 1/2 inch rod as a plunger. Pretty sure I have a vice big enough to do the job also. Give me a day or so to sort it out.
Great idea by the way.

Thanks and thank you for the ref math on this....only other question I have is repeatability on pressure for consistency from batch to batch....or puck to puck

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[ofitg]

Just crunching numbers shows that a 1/2 inch diameter hole is .19 square inches of area so a one ton press will give close to what's recommended for proper compression. The surface area is about one fifth of a square inch so one ton of pressure would give a full five tons of pressure.

According to Tenney Davis's book, Chemistry of Powder and Explosives, commercial manufacturers compress BP by applying 1200 PSI of pressure.

A 5-ton press (exerting 10,000 lbs. of force) should accommodate a disc-shaped puck up to 3.25 inches in diameter (8.3 square inches of surface area)...... 10,000 lbs / 8.3 sq.in. = 1205 lbs/sq.in.

A 1-ton press should accommodate a disc-shaped puck up to 1.45 inches in diameter.

[Eddie2002]

Well I gave it a try using some fines from a batch of screened. The cylinder and ram are 10 inches long and the end plug is a cut down 1/2 inch bolt with just a short section of it's shoulder acting as the plug which I held on with some tape while filling the cylinder. The fines were compressed from 10 inches down to 5 inches and left to sit under pressure for about a 1/2 hour in a old Emmert woodworking vice I'm lucky to have. Removing the powder plug needed to be done using the vice and ram to push out the compressed powder. The last inch or so wasn't compressed very well so I'm guessing I should of cranked the vice down a few more turns or flipped the cylinder around and rammed it from the other end. The closer to the ram the harder the powder plug appeared to be and it was apparent that the compression wasn't complete from end to end.
The picture shows what I was using for this first run. One of the problems is that the BP plug seems to grab onto the inside of the cylinder once pressed and needs a good push from the ram to dislodge it then it breaks into short pieces as it gets pushed out of the end of the 1/2 inch cylinder. For a small amount I think this would work, ended up compressing about one cubic inch.
I was in the middle of a welding job so didn't want to take it any further today. LOL

[indian joe]

Well I gave it a try using some fines from a batch of screened. The cylinder and ram are 10 inches long and the end plug is a cut down 1/2 inch bolt with just a short section of it's shoulder acting as the plug which I held on with some tape while filling the cylinder. The fines were compressed from 10 inches down to 5 inches and left to sit under pressure for about a 1/2 hour in a old Emmert woodworking vice I'm lucky to have. Removing the powder plug needed to be done using the vice and ram to push out the compressed powder. The last inch or so wasn't compressed very well so I'm guessing I should of cranked the vice down a few more turns or flipped the cylinder around and rammed it from the other end. The closer to the ram the harder the powder plug appeared to be and it was apparent that the compression wasn't complete from end to end.
The picture shows what I was using for this first run. One of the problems is that the BP plug seems to grab onto the inside of the cylinder once pressed and needs a good push from the ram to dislodge it then it breaks into short pieces as it gets pushed out of the end of the 1/2 inch cylinder. For a small amount I think this would work, ended up compressing about one cubic inch.
I was in the middle of a welding job so didn't want to take it any further today. LOL

Un even ness down the length of the tube would be the problem with pressing long cylinders - it happens enough to be a worry in compressed loads in brass cartridges. there would be a diameter point at which this ceased to be a problem ......................

[John McCorkle]

Un even ness down the length of the tube would be the problem with pressing long cylinders - it happens enough to be a worry in compressed loads in brass cartridges. there would be a diameter point at which this ceased to be a problem ......................

I am guessing this is an effect of friction between the grains and into the sidewall of the pipe?

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[indian joe]

I am guessing this is an effect of friction between the grains and into the sidewall of the pipe?

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could be sidewall friction ? I load 45/70 and 45/75 and the difference top to bottom is more in the bottleneck case but quite noticeable in both

[GregLaROCHE]

I think even new hydraulic presses are pretty reasonable today. I’m considering getting one just to have around for the odd job now and then.

[Eddie2002]

I'm pretty sure it was side wall friction since the closer to the ram the denser the powder was. The farther down the cylinder the less compression occurred. I could of kept cranking on the vice but had other jobs going and had to stop. Not bad for a first try though.
I just checked the dried out compressed chunks of powder and about an inch or two of it was dense enough so it couldn't be broken up by hand. With a little tweaking I think this would work but the big flat puck makers are way more efficient for quantity.
Well it didn't cost anything to make the ram press and I learned something so it wasn't a waste of time.