Compressing Black Powder

[eastwoodshooter]

Hello, I am having problems getting the weight right on my homemade black powder.
I made one batch using 5% dextrin as a binder and just compressing it by hand and then passing it through a screen while the powder was still wet and then allowing it to dry. The wight of this powder for 1/4 tsp was 17 grains.
I recently started trying to compress my powder to get a density closer to professional powder. I use a 20 ton press and a homemade powder die. I have pressed a puck putting as much pressure as I could on the press and then letting the puck dry for 24hours before granulating it. Once the puck is dry I use a mortar and pestle to break the puck into a 3fffg. I then weighed a 1/4 tsp of the compressed powder and am only getting 15 grains!! The compressed grains feel harder than the screened ones but it weighs less. So my question is, am I doing something wrong? Could the dextrin be messing up the weight? I weighed 1/4 tsp of professional powder and it weighed about 23 grains, Screened weighed 17 grains and Corned weighed 15 grains. The puck is rock hard before I try to granulate it so I'm having a hard time understanding why the weight isn't increasing.

[Tatume]

Welcome to the forum. Sorry I don't have much information for you, but you are trying to perfect a process that has taken other people lots of effort and ultimately made fortunes for them. Don't be too distressed that you don't get it right on the first or second attempt.

Good luck, and be safe.

[dondiego]

How accurate is your teaspoon measuring device? Do you heap it? Repeatability would be critical. Weigh ten teaspoon batches of the same powder to get an average weight. Just some thoughts.

[eastwoodshooter]

I am just using a regular kitchen teaspoon and getting it as leveled off as possible. I did a few more tests and found that the outside shell of the puck is harder and has a higher weight then the center. Do you suppose this is due to not being quite dry in the center? Or possibly that my pucks are to thick? Right now my pucks are 1" thick. Would reducing that help? I also was wondering if it could be possible that it doesn't have enough moisture? When I press the puck currently it does press some moisture out.

[indian joe]

I am just using a regular kitchen teaspoon and getting it as leveled off as possible. I did a few more tests and found that the outside shell of the puck is harder and has a higher weight then the center. Do you suppose this is due to not being quite dry in the center? Or possibly that my pucks are to thick? Right now my pucks are 1" thick. Would reducing that help? I also was wondering if it could be possible that it doesn't have enough moisture? When I press the puck currently it does press some moisture out.

A one inch thick puck is gonna take a loooooooong time to dry properly - days moreso than hours.
If it bleeds moisture its plenty wet plus some.
Also your measuring is higly suspect - use a boolit shell - tap it ten or twenty times and top it up OR drop tube it

[Tatume]

Tapping is not conducive to good precision. The accepted practice is to dip and strike level.

[indian joe]

Tapping is not conducive to good precision. The accepted practice is to dip and strike level.

No........................................

Dip and strike level is not conducive to good precision . The accepted practice is to tap the measure ten times, top it up again then level it off

See I can do that too!!! Accepted at your place is different than accepted at my place !! Dip measure works fine with commercial powder - good bulk density, graphited so it runs nice, maybe tumbled as well -- but we talkin here about the homebrew stuff - any kind of longish measure you will get times when it bridges some in the measure and will get you in a ton of trouble with consistency unless you take extra trouble to make sure its settled in the measure properly - tapping the outside of the measure as you fill it is one good way to do that - same applies to pouring it into your front end loader - if you dont whack that caplock on the side a few times to settle the powder (or some other thing that has the same effect) you will have misfires/fail to ignite incidents at the most embarrassing moments. How do I know this stuff? been shootin my own made powder the last three years with some good competition wins under my belt doin it - it behaves different than bought stuff (thankfully)

[Tatume]

Sorry. I should have been more specific. You are right, black powder shooters do tap measures, so it is an accepted practice among shooters. I was thinking in terms of laboratory procedure, since the OP is attempting to determine density.

[indian joe]

Sorry. I should have been more specific. You are right, black powder shooters do tap measures, so it is an accepted practice among shooters. I was thinking in terms of laboratory procedure, since the OP is attempting to determine density.

You are right also, provided that the fill and strike measure is dimensioned so that the powder cant bridge at all - thats a different shape than a cartridge case or most blackpowder measures tho! .......I think its highly likely that his powder has a moisture issue that is more important than measuring density - BUT - I give him three cheers for having a go - he will get this sorted - (hint- much sooner if he pays close attention to what Fly writes) - and when he does he will have achieved something rather special.

[OverMax]

Dextrain? Why add if your intentions are to press pucks. Its not required. If screening meal powder to F size over a catch tray. A light dampening spray of 2% dextrin water blend is all that I found_needed.
Pucking Equipment: Ceramic burr only coffee grinder (amazon) and kitchen stainless screen strainers (Walmart) will eliminate allot of work when grading to size. When I did at one time puck. The usual drying time was at least a week. Pucks I dried were no more than 1/4" thick as the burr grinder does have limits in accepted chunks & pieces.
In regards to 15 grs vs 17 grs in volume difference? I haven't a clue.

[carbine]

what about the Making Black powder sticky at the top of this page. They couldn't help?

[Harter66]

I wonder where Fly is ?

I will also say that your puck is too thick , however you also need to consider dia if you're pressing a 1×1" puck you're probably ok , now something the size of a hockey puck not so much .

My reading has suggested that the dextrose isn't necessary for pressed and corned powder . Also that it is at it's density peak with a loading of 12-1500 psi on a 1.5×.375 ish puck .

The screen trays mentioned by Overmax are the ticket . Amazon maybe they had a 3 screen nesting set something like a 60,80,100 mesh . Basically you get everything too big in the 60 , FFg in the 80 , FFFg in the 100 . You regrind the 60 tray bottle the 80&100 trays and press the stuff that passed through the 100 mesh .

I'll second the ceramic coffee grinder also .
I bought mine on a this is so stupid cheap sale I bought 3 for like $27 shipped so I got one for the kitchen and 2 for the shop .

I suspect that your density is being caused by the size of the puck .
The guys I learned from do a 1200 psi press and a 15 minute hold .
A couple do such scientific means as placeing the press under the right front spring pad of the old Jeep and lifting the tire 1" with a 2000# bottle jack , go pour a cup of coffee come back R&R the press tool reloaded , lift , drink half a cup , repeat , 4th cycle take the cup back inside . A couple of others just wing it with a $25,000 machinist press digitally calibrated to +- 1% for 1310 psi set and a 10 minute 43 second hold .

Facts above but slightly tongue in cheek .

Several have after 20+ batches with lab grade kno³ and sulpher perfected their charcoal , press technique and with some 50-60 batches since are making powder as good or better than Goex one guy is very close to duplicating Swiss .
It ain't me . If I get my screened within 100 fps in 36&44 pistols with 70% as much by volume 777 and I'm just happier than a pig in .........a wallow .
If I get the corned beat down to 110% volume of Goex and 115% of 777 I'll be pickled tink . If I get my FFFg to match FFg Goex or beat it every batch I'll be bragging it harder that my grandsons first grandslam .

[eastwoodshooter]

Dextrain? Why add if your intentions are to press pucks. Its not required. If screening meal powder to F size over a catch tray. A light dampening spray of 2% dextrin water blend is all that I found_needed.
Pucking Equipment: Ceramic burr only coffee grinder (amazon) and kitchen stainless screen strainers (Walmart) will eliminate allot of work when grading to size. When I did at one time puck. The usual drying time was at least a week. Pucks I dried were no more than 1/4" thick as the burr grinder does have limits in accepted chunks & pieces.
In regards to 15 grs vs 17 grs in volume difference? I haven't a clue.

I have the dextrin in there because for my first batch I was just going to screen it but then decided to try corning it. So I have 10lbs made up with the dextrin in it.

[eastwoodshooter]

Could any of you give me what Weight/Volume you guys are getting so I can kinda compare mine to it? I am comparing mine to some of my grandpa's 40 year old FFFg Goex powder. I tried tapping my 1/4 teaspoon to make sure that it was all settled and as accurate as possible and am getting 23.4 Grains for the Goex and 18.9 Grains or 1.225 grams for my corned powder. I made my pucks smaller this time by putting plastic slip sheets between the powder before compressing it and then let it dry in the sun for a day and a half. Would the plastic slip sheets possibly cause an issue?

[mold maker]

Not familiar with the term slip sheets, but I also reduce the thickness of the pucks by placing cut milk jug plastic between layers of BP in the puck die. I haven't found any deteramental effects.
The thin pucks dry quicker, more consistently, and shatter with less effort.

[eastwoodshooter]

Not familiar with the term slip sheets, but I also reduce the thickness of the pucks by placing cut milk jug plastic between layers of BP in the puck die. I haven't found any deteramental effects.
The thin pucks dry quicker, more consistently, and shatter with less effort.

Yeah the "slip sheets" is a term I picked up from working at a factory where we use thin layers of plastic to separate layers of boxes on a pallet. But it's the same idea as you are using with the cut milk jug plastic. What are you using to break your pucks down to the right grain??

[indian joe]

I have the dextrin in there because for my first batch I was just going to screen it but then decided to try corning it. So I have 10lbs made up with the dextrin in it.

same here ! did we really need to make ten pound of meal ? .....it was kinda fun though .

[indian joe]

Could any of you give me what Weight/Volume you guys are getting so I can kinda compare mine to it? I am comparing mine to some of my grandpa's 40 year old FFFg Goex powder. I tried tapping my 1/4 teaspoon to make sure that it was all settled and as accurate as possible and am getting 23.4 Grains for the Goex and 18.9 Grains or 1.225 grams for my corned powder. I made my pucks smaller this time by putting plastic slip sheets between the powder before compressing it and then let it dry in the sun for a day and a half. Would the plastic slip sheets possibly cause an issue?

I put em up in the other place
5FA GOEX (same vintage as yr Grandpa's ) 138 grains -I think FF in this measure would be a few grains less? - that 5FA packs in heavy becuse of the variation in grain size
My Puck powder ..FF grading 115 grains
My Screened powder .. FF grading 108 grains

Your numbers x 6 - we are close to the same thing. !!! When you figure it out tell me, it looks like we both makin the same mistake here ---- I am very happy with my results when I pull the trigger - its the cleanest burning blackpowder I ever shot - and its working at the target end.
23.4 x 6 = 140.4 Goex FFFg
18.9 x 6 = 113.4 Corned

[eastwoodshooter]

Thanks for the numbers. Yeah if I ever get it figured out i'll let you know. I have read many posts on this site with people claiming to get the same or better density than GOEX so I know it has to be possible. I'm waiting to get my die I ordered from fly, then i'll try making my pucks thinner and keeping them in the press longer and see if that makes a difference. I'm also trying to think of a better way to granulate it so I don't break it down to worthless dust as much. It's just hard for me to get how compressing something with 20 tons of pressure is currently only increasing my density by 10% more than what I can press by hand!!

[indian joe]

Thanks for the numbers. Yeah if I ever get it figured out i'll let you know. I have read many posts on this site with people claiming to get the same or better density than GOEX so I know it has to be possible. I'm waiting to get my die I ordered from fly, then i'll try making my pucks thinner and keeping them in the press longer and see if that makes a difference. I'm also trying to think of a better way to granulate it so I don't break it down to worthless dust as much. It's just hard for me to get how compressing something with 20 tons of pressure is currently only increasing my density by 10% more than what I can press by hand!!

I think impatience is a major factor (for sure with me ) busting up the pucks is a lot of work - one day I will make a crusher for that - yeah seems like lots of dust and FFFFgrade (not so bad when you weigh it all) - I put the dust back in the next batch of meal and have a buddy with a Colt lightning 357 mag for his wife - he just loves the FFFFg - so he gets what we dont use for flinter priming.