Bp mesh sizes?

[FieryCreations]

Can someone recommend a few mesh sizes that should cover fireworks and sporting BP? I'm looking through charts on Skylighter and just confusing myself. 

I see 2F, 4F, and Meal D are the commonly used ones. But the mesh range it gives for each seems pretty large and I'm not sure which ones to order. Take 2F. It says mesh 4-12. Does that mean 2F will fit through a 4 but not a 12? If it fits through a 4, it would fit through anything larger so that can't be right? Do I just grab a mesh in the middle (8)?

[cmjlab]

I don't know much about sporting grade B.P., as I don't have a B.P. firearm so I'm not to concerned with it.  

You are correct about mesh size, -4 +12 would mean it falls through 4 mesh screen, but is retained on a 12 mesh screen (i.e. smaller than a 4 mesh screen, bigger than a 12 mesh screen).  The implied information is that the B.P. has already been screened for Cannon Grade (1Fa) before the next size was screened for.

It would probably not work well to have fireworks / sporting B.P. due to the size difference between Fa (larger) and Fg (smaller).  I don't imagine 4Fa is going to fire the same as 4Fg, as the latter is much smaller.

As for most useful mesh sizes for fireworks, in my opinion, the ~2Fa (Lift / Burst for 3" to 6", I don't make anything larger), ~4 Fa (Burst / Lift, for smaller shells and inserts), and ~Meal-D (spolette's and priming) are the most useful cuts. 

However it depends on what screens you have to use.  Since fireworks are not as specific about grains as a B.P. rifle or B.P. cartridge are, IMO you just need to be able to screen coarse B.P., Medium B.P. and Fine B.P. is close enough.  For me, I sort into ~2Fa(ish) with -4 mesh +8 mesh, and ~4Fa(ish) which is -8 mesh + 16 mesh.  My "Meal-D" is anything down to -16 ~+40 mesh (sometimes I'll sort the -40 + 60 mesh if I don't plan to make more B.P.), and anything smaller is re-used.  Anything larger than 4 mesh is re-broken up to capture smaller cuts.

[Arthur]

In historic and modern professional BP there has been a need for all the grades of Fa and Fg in varying proportions. In modern BP each person has a desire for their favourite cuts. However all the unwanted portions can be returned to the pressing process and re-corned as different grades.

[AustralianPyromaniac]

For what I do 4/10/20/40 is enough. BP screens out to -4+10 (2FA ish) and -10+20 (4FA ish). I only make small shells, so these grades work well for lift and break.

40 is for mixing and fine screening. 20 is for screening unmilled chemicals and separating milling media. And the 10 mesh doubles as a screen for micro crackle. 

That covers everything I have needed to do so far. I made some other screens years ago, but they're a pain to use so I now consider chemicals to have two states, "approx 20 mesh from the bag" and "airfloat after I ball mill the hell out of it" 

No clue about firearms. 

[Richtee]

Pretty sure the only diff between an “FA” and an “FG is the G’s been polished with graphite and further screened of fines. The grain sizes are equal.

 

I use 2 and 3F (sometimes I “g” it) mostly. Have a bud who shoots BP arms. I supply him a bit of 2Fg as well.

[FieryCreations]

If I'm understanding correctly, it's sequential, and I need both the larger mesh and smaller for each grade I want to make. 

[Arthur]

FA powders are that material that passes the larger mesh but sits on the smaller mesh.

FG powders re graphite glazed and are smaller than FA powders of the same number. 

Sieves made into plastic bodies can, in the USA, be sourced from suppliers of gold prospecting equipment. Usually they are stackable so you can sort powder into FA cuts simply by stacking the sieves, loading the top one and shaking the stack. The fortunate thing about BP is that it can be damped, repucked and corned and sieved again with no harm. so if you have too much of one mesh cut then rework it to fill in the gaps.

[FieryCreations]

4 hours ago, Arthur said:

FA powders are that material that passes the larger mesh but sits on the smaller mesh.

FG powders re graphite glazed and are smaller than FA powders of the same number. 

Sieves made into plastic bodies can, in the USA, be sourced from suppliers of gold prospecting equipment. Usually they are stackable so you can sort powder into FA cuts simply by stacking the sieves, loading the top one and shaking the stack. The fortunate thing about BP is that it can be damped, repucked and corned and sieved again with no harm. so if you have too much of one mesh cut then rework it to fill in the gaps.

Yeah I have a few of those from prospecting but they're pretty big. I'm trying to figure out exactly what screens I need to start with so I can buy whatever I don't have. Can someone just recommend 3 or 4 of the most necessary ones for pyro. I can worry about sporting BP later.

Also, is an old metal meat grinder with the hand crank good for grinding up pucks to corn? 

[cmjlab]

The grinder is what a few people who actually puck and corn b.p. for fireworks use, are using.  It appears to work really well.

One thing you should know up front about pyro - if you ask a question on how to do/make something, you'll get a ton of different answers!  (Good News though - most of them will probably work!)

If I had to choose 4 mesh sizes to start I'd go with 4 mesh, 12 or 16 mesh (most kitchen strainers made with wire mesh around me around approx. 16 mesh), 20 mesh, 40 mesh.

If I was short on money or frugal, I'd buy the 40 mesh, but try to make my own for the others, using cheaper screen.  Hardware stores sometimes carry rolls of 1/4" and 1/8" hardware cloth (wire mesh) that could work for making 4 and 8 mesh screens (and can be purchased by the foot pretty cheap). I'd find the coarsest wire kitchen strainer to serve as 12 or 16 mesh.  I'd buy a roll of metal window screen to make a 20 mesh screen and drying screens. These are just some alternative ways to make cheaper screens, but will not last as long as quality stainless steel screen and homemade wooden frames (sealed with polyurethane). 

 

Edited December 24, 2023 by cmjlab

[Arthur]

2, 4 and 6 FA would be my initial choices. The sieves for prospecting come down to 4 inch diameter.

[FieryCreations]

2 hours ago, cmjlab said:

The grinder is what a few people who actually puck and corn b.p. for fireworks use, are using.  It appears to work really well.

One thing you should know up front about pyro - if you ask a question on how to do/make something, you'll get a ton of different answers!  (Good News though - most of them will probably work!)

If I had to choose 4 mesh sizes to start I'd go with 4 mesh, 12 or 16 mesh (most kitchen strainers made with wire mesh around me around approx. 16 mesh), 20 mesh, 40 mesh.

If I was short on money or frugal, I'd buy the 40 mesh, but try to make my own for the others, using cheaper screen.  Hardware stores sometimes carry rolls of 1/4" and 1/8" hardware cloth (wire mesh) that could work for making 4 and 8 mesh screens (and can be purchased by the foot pretty cheap). I'd find the coarsest wire kitchen strainer to serve as 12 or 16 mesh.  I'd buy a roll of metal window screen to make a 20 mesh screen and drying screens. These are just some alternative ways to make cheaper screens, but will not last as long as quality stainless steel screen and homemade wooden frames (sealed with polyurethane). 

 

Thanks. I guess you do get different answers. From what I gathered on Skylighters charts, the 100 mesh for meal d was mandatory. I do have little 4" 50 and 100mesh screens for gold flake classifying. And probably a 4 and 12 bucket classifier. That helps, thanks. 

[cmjlab]

Yeah, I'm not sure what 100 mesh B.P would be critical for.  Also, I figured I should have explained what I use the various mesh sizes for, that I discussed earlier.

4 Mesh = Good for screen cut stars, and sizing stars.

4 to 12 or 16 mesh = gets me the 2Fa(ish) b..p. for lift and sometimes burst. 

12/16 to 20 mesh = Sorts out my B.P. to 4Fa(ish) which I use for breaking small shells and inserts.  Can also be used for lift in smaller shells.

20 Mesh = Good for first mixing of star comps, slow flash and other mixes. Good for breaking down clumpy chems too clumpy for a finer mesh.

20 to 40 Mesh = Get's me my 5/6/7Fa B.P., which is good for priming (good granule size to catch fire from a break charge easily), and making spolette's (I usually set aside a couple pounds of a batch, time it, then I have a consistent timing source). I've also used it for tiny bombette breaks (though slow flash is better IMO).

I also have a 60 mesh screen, which I use to screen comps that have well milled chems, or to break up clumpy chems after putting them through a 20 and 40 mesh. 

I also periodically use the 40 to 60 mesh to capture smaller grains of B.P. which is prob closer to Meal-D for spolette's.  But I haven't done that in a while.

 

[Arthur]

100 mesh does me for meal coated rice hulls or meal coated rice krispies. 

[cmjlab]

Interesting, I did try some fine mesh B.P. for priming stars once because I didn't know what else to do with it at the time, and it seemed more difficult to get it to stick to the stars.  However, it was -60 mesh since that's the smallest I have.

[FieryCreations]

10 hours ago, cmjlab said:

Yeah, I'm not sure what 100 mesh B.P would be critical for.  Also, I figured I should have explained what I use the various mesh sizes for, that I discussed earlier.

4 Mesh = Good for screen cut stars, and sizing stars.

4 to 12 or 16 mesh = gets me the 2Fa(ish) b..p. for lift and sometimes burst. 

12/16 to 20 mesh = Sorts out my B.P. to 4Fa(ish) which I use for breaking small shells and inserts.  Can also be used for lift in smaller shells.

20 Mesh = Good for first mixing of star comps, slow flash and other mixes. Good for breaking down clumpy chems too clumpy for a finer mesh.

20 to 40 Mesh = Get's me my 5/6/7Fa B.P., which is good for priming (good granule size to catch fire from a break charge easily), and making spolette's (I usually set aside a couple pounds of a batch, time it, then I have a consistent timing source). I've also used it for tiny bombette breaks (though slow flash is better IMO).

I also have a 60 mesh screen, which I use to screen comps that have well milled chems, or to break up clumpy chems after putting them through a 20 and 40 mesh. 

I also periodically use the 40 to 60 mesh to capture smaller grains of B.P. which is prob closer to Meal-D for spolette's.  But I haven't done that in a while.

 

Ahh that helps even more. When you say screen cut/sizing stars, I'm guessing I don't need that if I'm using a start pump plate?

I also heard in a video a guy say right out of the ball mill is basically meal, so I probably don't need a 100 mesh I guess.

I really need to find a good book on the basics or something. I'm just trying to get all the stuff so I can tinker as I go. I bought a 1lb rocket tool set with NEPT tubes, 3" shells, lift cups, rice hulls, and a small 3/8 star plate with extractor. 

[AustralianPyromaniac]

8 hours ago, FieryCreations said:

Ahh that helps even more. When you say screen cut/sizing stars, I'm guessing I don't need that if I'm using a start pump plate?

I also heard in a video a guy say right out of the ball mill is basically meal, so I probably don't need a 100 mesh I guess.

I really need to find a good book on the basics or something. I'm just trying to get all the stuff so I can tinker as I go. I bought a 1lb rocket tool set with NEPT tubes, 3" shells, lift cups, rice hulls, and a small 3/8 star plate with extractor. 

Most people will make cut stats first, rather than pumped. I think this is mainly just because star plates are expensive, but if you have one that's great. Still, many color comps are shock-sensitive and shouldn't be hit with a mallet, which then means you then need a press to make those in a star plate, which you may also have. The equipment needed adds up quickly compared to cut stars. The advantages of ease of manufacture and lack of equipment needed will always make cut stars invaluable. Also, if the star burns too long/ short, cut star size can be adjusted easily, but pumped stars have little room for size change.

As you said pumped stars do not require screening, they are all exactly the same size. Rolled stars tend to grow unevenly and require regular screening to control this, for which, screens are needed. Cut stars do not really need screening - if they are well made well, they should all be the same size, except some on the edges of the patty, which are easily discarded by eye. There is a great photo on the APC home page showing some very well-made cut stars, which are all nearly identical. A screen can be useful for marking a patty for cut stars, a 4 mesh screen can mark a patty of star comp for 1/4" cut stars for example.  

I know Skylighter made a tutorial on alcohol-bound BP using redgum and a 100-mesh screen to prepare the chemicals, is that maybe what you're referring to about the 100 mesh? I'd bet well-milled BP was at least 200-400 mesh, talc powder is about 1000 mesh, BP may even be that fine, but I wouldn't know for sure.

I think the term Meal D is based on the Goex standard, and means everything that falls through a 40 mesh when they screen their powder, which looks like very fine sand. You can use BP straight from the mill when Meal D is called for, which isn't that often, the advantage of Meal D is it's not dusty like mill powder is. Something may say "prime with meal D" but mill powder can be used without issue.

There isn't any great print book that covers amateur manufacture. Fireworking.com has great content but is paid, the Fireworking 101 course from FW.com course is free on YT and the Turbo Pyro ebook book here on the APC is also very good 

 

 

[cmjlab]

Yep, if you are pumping them you are good to go, just have to prime them.  Screen cut stars is a quick / easy method to make cut stars using a screen to slice instead of a knife, one row at time.  They also come out perfectly consistent with a screen.  You leverage Parlon / Acetone to make screen cut stars "search "rubber stars").

In my *opinion*, , right out of the mill = mill dust.  Again, B.P. is one of those subjects (like religion and politics), which will have a million answers and probably lead to a "heated debate" over who's B.P. is better, and a lot of fireworks have different names for various B.P. processes, products, and uses!

However, *IMHO*, Meal-D is a mesh size (or cut of B.P.) which implies you have to process it first.  Specifically, Meal-D has officially referred to the leftover fines from corning and pucking your B.P. So because of the processing Meal-D is a granulated B.P. which improves it by making it free-flowing and less dusty to use/handle; and though it's a small granule, is still pretty different to the dusty talc like "mill powder".

For a book, it depends on what kind of devices you want to make.  Most here can fit into three categories: Shells, Rockets, or both (but I still think even those who do both, still make more of one type than the other).  I'm more of a shell person, but make rockets here and there.  If you want to learn Italian-American style cylinder shells, then the Fulcanelli will have everything you need to get started.

 

[Zumber]

12 hours ago, FieryCreations said:

I really need to find a good book on the basics or something. 

"Fireworks The Art science and technique " by Dr Takeo Shimizu.

Fireworks principles and practice by Ronald Lancaster.

Skylighter pyro projects cover all basic projects.

Here are few suggessions its really worth.