Tim;
When you break your pucks up, start screening your powder while the chunks are still big. You can't over screen it. Every time you break them further down, screen it. That has shown my biggest decrease in fines. I started out breaking up pucks, just like you are. And, I was getting a comparative amount of fines, to yours.
If you can, get you a ceramic bladed coffee grinder, and start grinding your chunks when they are the biggest the grinder will accept and set it on its largest setting. Then, every time you run it through, screen it, and run each load through 3 times before you decrease the setting. Go small settings every time, and screen it three times, on each setting. This should get your fines below 40%, if you are seeking 2F and 3F and maybe as little as 30%.
If you are getting good compression (density) you really shouldn't need any binder, but 2% dextrin shouldn't show an excessive slowing of the powder. 90% of Commercial Powder is about normal, for a lot of folks. To get it up, the only thing I've found is home made brown Charcoal, which will get your densities up to Commercial.
I've heard other people report that Skylighter Charcoal is not superior, and if it is not, there's your main problem, with the speed. They are using it as lift and burst powder, and don't care if it is optimum, or clean. It just needs to work and be reasonably uniform, for their use.
If you can, start making your own Charcoal, from a known good Powder wood. Where you live, you should have an abundance of Black Willow, Eastern Red Cedar, Sassafras, and other woods; which are great for making Powder.
Here is a link to a good site, which has done a lot of testing. It's a good and informative read. I hope some of this helps, and good luck! http://www.wichitabuggywhip.com/fire...oal_tests.html
For some reason I thought you had said your fines were 40%, is the reason I used that number. After reading a second time, I don't know where I got that.
Last edited by DoubleBuck; 01-30-2023 at 09:31 PM.
I think most of their stuff is geared towards fireworks BP. Works fine for that, but a bit slow for sporting use.
Years ago I bought some chemicals from them for making 4th of July salutes. Still had some charcoal left from that order that was old, but still sealed in a plastic bag. Used it for my first try at making BP. It was terribly slow burning. Then I discovered this thread and these Yah Hoos straightened me out.
Last edited by HamGunner; 01-30-2023 at 10:11 PM.
73 de n0ubx, Rick
NRA Benefactor Life Member/VFW Life Member
I really don't see how you can have 90% density compared to Goex if the pucks are pressed in a vise.
I do agree that the powder kit you bought is for fireworks.
Yes,
It will shoot in a gun.
But like you said , it will be much slower burning , and probably be much dirtier.
But the kit let's you practice the skills you need to get started.
I have also found that if you add Dextrin to pucks.
You raise the density and get less fines.
But, It burns slower and is harder to ignite.
It is best to stick with the Sulfur for the puck binder when compressed.
yah well the dextrin in the pucks was a plan B deal after plan A went haywire.
ps I am getting about 92-93% of Goex density in pucked powder - I dont measure pucks just compare drop tubed/vibrated charges of finished powder in a measure (45/70 shell usually) . My puck pressing system is a bit "agricultural" - cant see the point in measuring / weighing for density at that point (others do it - thats ok) I just reckon its the finished powder in the measure that matters .
Last edited by indian joe; 01-31-2023 at 12:09 AM.
I break pucks initially using a small brass hammer inside a plastic PVC cap, and I stop crushing when the pieces are small enough to fit into the coffee grinder with its ceramic burrs - going any further just creates more dust. That first grind is quite coarse, yielding 1/16" to 1/8" chunks - but - it's also best to screen after the initial grind because some amount of usable powder will pass through all of the screen sizes. After the first pass, I'll run a second pass on everything that remained on the screen, but without adjusting the grinder. That yields additional powder in all sizes - then I tighten the burrs for the third pass and screen again. After 4-5 cycles, there will be 1F, 2F, 3F, 4F and dust accumulated on the screens. My dust yield is generally around 20% or less of the total in weight, and my 2F screen catches the most powder. If I grind a pound of pucks, I'll get 9-10 oz of 2F with the remaining sizes making up the balance. I keep the dust separate and toss it in with a fresh batch the next time I make green meal.
I used to get about 50% fines but discovered it was best to minimize the pulverizing and stick to grinding.
Today I decided to see what the compression differance is between compressing with a vise or a 20 ton press.
I just wanted to put my 2 cents in , Literally.
I started off by putting a Penny in my 6" bench vise.
I clamped the vise shut , and tightened it as tight as I could using a 3' long cheater bar.
The penny showed no signs of compression.
So I put a penny in my HF 20 ton press.
At full power.
The penny compressed down .005".
The diameter also expanded .030".
I am not saying that a vise could not compress the green powder into some kind of puck.
But I think a press will compress it much greater.
Just my 2 cents.
I don't have a load cell to test my vice and it is probably not 20 ton but I am sure I can get measurable compression on a penny. I am not getting a 20 ton press just to make powder. I can buy more powder than I would use for the cost of even a cheap hydraulic press. My pucks are smaller diameter than most so I don't need as much compression force. My pucks get compressed from half inch to a quarter inch and I start with hand compressed meal. As much meal as I can pack in the die.
Tim
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
My process is a little different but amounts to the same thing I expect.
Remember my pucks are small, about the size of a "Tums." Less than inch by a quarter inch. I crush one in the mortar and pestle (M&P) screen thru my course screen and put chunks back into the M&P with another puck. Crush and course screen, rinse and repeat until everything passes the course screen (2f pass). Then I screen with my medium screen, 2f no pass 3f pass. Then I screen with my fine screen 3f no pass, 4f pass. At that point I did screen some with an extra fine screen, 4f no pass fines pass but I did not try to get all the 4f and let a lot of it be fines. I might have less fines if I really screened out all the 4f but I don't see the point. I want mostly 2f and 3f. At no point do I grind, I just crush the pucks and big chunks and screen.
I knew from the get go that that the charcoal was not going to be the best but I can't believe how bad it is. I have a pressure cooker pot and some cedar and balsa. I guess I am going to have to make my own charcoal unless top grade charcoal can be bought. The cedar is old fence boards, I know it is cedar, I can tell the cedar from the pressure treated. I probably have more balsa than most people can put their hands on and I have a lot of scraps that can't really be use for much. I heard that balsa makes good charcoal, any more good advice is appreciated.
Tim
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
I made up some Balsa Charcoal.
I cooked it slow and stopped when it still had sort of a brown tint to it.
It works really great.
I actually like it better than Willow.
But the Balsa is not as available , and a little more expensive.
One thing I noticed when cooking the Balsa.
Make sure all the pieces of wood are about the same size.
Otherwise,
The thin or smaller pieces cook so much faster.
I made mine out of a couple of 3x3 hunks of wood that I cut into 1/2"x1/2" sticks the length of the paint can I was charring them in.
Last edited by LAGS; 02-01-2023 at 12:00 PM.
yeah good point if you keep the diameter small enough proly get enough pressure but its back at that PITA place where slow and frustrating starts to remove the fun.
I made my press - had an old 20 ton truck jack that worked and the rest came off the scrap heap - 3 or 4 hours cutting and welding - had the stick rods, I paid 5 bucks for half a wheelbarrow from a yard sale 20 years ago - so cost me time and electricity - tis how I do stuff!
Also made my pressing dies - again courtesy of the scrap heap mostly - and a piece of 3" schedule 80 PVC that I happened upon.
dtknowles;
I don't know what size vice you are using. I saw you said you are using a 1 inch die.
I pulled up some old information on vices. A 1" 8 thread bolt, which is what some American made 8" vices use, calls for 300 pounds of torque, and supplies 10,200 pounds of clamping force. That converts to over 12,900 pounds of compression on a 1" die. If the target compression for 1.7 gram per CC density is 3,500 pounds, and you are using an 8" vice, the math says you can do it. Times nearly three. A 6 inch vice with a 3/4 10 thread screw calls for 138 pounds of torque and will supply 5500 pounds of clamping force. On your 1" die, it says you can get 7,004 pounds per square inch. Which will still get your 3,500 pound target (if that is what it actually takes).
I don't know if it will or will not make viable pucks, but the math says it will.
By the way; that 8" USA made Wilton vice that I paid a hundred bucks for 50 years ago, is nearly $800, today. But, whatever it would do the day I bought it, it will still do today. That's the difference in the Chinese BS they sell today as a 'quality' vice.
Balsa Charcoal is the berries. It is my fastest linear burn rate powder. It burned a four foot 1/8 inch line in my tester, in less than one half second. The Chronograph said it was not my best, but I made it four or five years ago, before I knew that I probably over cooked every batch of charcoal I made until learned different. I have a 12" X 6" X 6" piece I have been saving until I know I can cook it correctly and I plan to cook it up.
If you have Balsa at your disposal, look no further.
Last edited by DoubleBuck; 02-01-2023 at 06:07 AM.
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |