Granulating Black Powder

[Hector]

I have been working on my black powder for a while, but I'm having trouble granulating it. The formula I'm working with is 70KnO3 15Charcoal 10sulfur and 5 dextrin. The real problem is that when I press the dampened composition through my coarse coffee strainer the grains stick to it and don't fall off... I would like them to fall off of the darn thing while they are still proportionate. It's frustrating, I end up getting a few okay grains and a bunch of ones lumped together. Perhaps it is too wet... Could I get a little help[ here? how do you "pros" do it? Thanks for your time.

[whitepyro]

Your problem is you have too much water in your composition. When adding the water, add it in small portions and mix it every time you add it until it gets to the right consistency. It should not be sticky half dry half damp . Experiment around with the wetness until it comes right. Hope that helps

[Hector]

Thank you, I kind of figured that was my problem, I'll try it and see what happens.

[californiapyro]

I ran some tests and figured out that my hand granulated bp was actually equally as powerful as my bp on hulls. thus, I now use coated hulls 4:1 for all my bp needs.

[arial-shellz-R-US]

Granulating becomes very easy if you use a mesh screen and push the wet BP through that, don't get your BP too wet or your granules clump together and you may get granules which are too big. A cheese grater also works well

[houseoffire72]

when i granulate my bp i wet it with 50% rubbing alcohol witch has water already in it, the alcohol makes the water wetter by breaking the surface tension of the water to pentitrate the bp comp thus using less water... it should be somewhat dry yet damp enough to hold it together and mixed very well I then granulate through an alum window screen onto a drying rack of sorts covered in kraft paper and set out to dry... I hope this helps:)

[Chris H]

Correct me if I'm wrong, but every coffee strainer I've ever seen is really too fine to be granulating BP for. I typically granulate through a 4 mesh screen for use in lift, break, and polverone to simulate 2FA. Depending on what you're doing, smaller may be more suitable.

I've found the "end point" of wetting with dextrin bound meal is the point where you can compress it together into a clump and break it in half with no to very few crumbs or granules falling off. SGRS behaves similarly, but feels different.

Believe it or not, there is actually a right and wrong way to granulate too. You want to take clumps of composition and press them through the screen, not grate it like cheese (guess how I feel about the suggestion to use a cheese grater :) ). Pressing rather than grating gives rounder granules that are approximately the same size as the screen. If you grate the BP you get what you would with cheese, long thin strips, which will partly break down into significantly smaller pieces as well as retaining larger pieces, and not hold up as well. Not to mention that it allows for the stuff to fall through easier, rather than getting smeared and coagulated on the screen.

[Hector]

OMG a 4 mesh screen? That's is approx .2" openings.... that's more like small stars than granules....

[Chris H]

You have heard of 2FA, right? -4+12 mesh

[Chris H]

This 2 minute edit window kills me sometimes.

2FA probably will not work for very small shells, but then again if I make them they're typically inserts. I use 4FA(-12+20) for lifting everything from 3" ball shells and down. 2FA will work for everything up through 36" shells. Using somewhat standard cuts of BP makes sharing information and having others recreate my work if they want makes things easier. On a 1 kilo batch, granulating through the 4mesh screen I get roughly 60% "2FA" sized particle, 30% "4FA", and 10% meal D and fines.