Most commonly used screens & their uses

[Dylman]

So as I continue down the hobbyist pyro rabbit hole. I've come to the question of what screens to buy. I'm using the bucket drying method due to the fact I'm limited on space, so I was going to get a set of 5 classification screens used for gold mining. I'll post a pic of the available sizes can someone please help me in choosing which to pick. Hopefully the retailer will allow me to pick & choose what I need otherwise I'm going to have to opt for the 9 screen set. Oh well I don't know how to post a pic. So here's the list 2,4,8,12,20,30,50,70,100. Thanks for the help. I'm excited to see your answers

[davidh]

The classification screens suck. They are small and tend to be expensive. I recommend making bucket screens. They are cheap, work well, and are easy to store. Buy your screens from https://www.mcmaster.com/. Just buy the cheapest 304 stainless woven wire mesh screen in the mesh size you need. DO NOT fixate on exact mesh size vs. opening sizes. It will make absolutely no difference in your results. When they wear out (and they ALL wear out), just buy a new screen, cut off about 1/4" of the old bucket to remove the old screen, and attach the new screen. The internet is rife with info on how to make bucket screens.

 

I recommend 4, 12, 20 and 40 mesh screens. Maybe one more a bit finer to break up clumped chems, say 60 or 80.

 

Note that 4, 12, 20, and 40 give you cuts for 2FA, 4FA, 5FA, and meal black powder. 20 and 40 are standard sizes for mixing (one pass through 40, two to three passes through 20). 12 is a good size for granulating comp for ramming/pressing. 4 is a good size for separating out your milling media.

 

Pro tip: use a wet-cut tile saw to cut the overlapping wire screen from your finished bucket screen. It cuts it like butter, resists cutting the plastic, and will leave a finished edge with practically no snagging or scratching.

 

Mesh Opening (%) Wire Dia Product ID Price for one square foot
4 × 4 0.203" 66% 0.047" 85385T28 $17.93
12 × 12 0.06" 52% 0.023" 85385T56 $10.48
20 × 20 0.034" 46% 0.016" 85385T73 $8.74
40 × 40 0.016" 38% 0.0095" 85385T89 $7.99 (this isn't the cheapest, but it will wear better)
80 × 80 0.006" 19% 0.007" 85385T97 $8.14

Edited June 13, 2020 by davidh

[spectra1]

Just for a different opinion I personally like classification screens. They are not small at all and are basically the exact same size as home made bucket screens. I had originally made my own wood box screens with quality mesh and if I could do it again as a beginner I would have just bought the classification screens. If you shop around you can find them for cheap. I completely agree with the above post about sizes and usage.

[Dylman]

Davidh, so given the screen choices I have what would be your 5 to work with. I'm aware I can buy screens to make them but I don't have the wood working tools. To build the boxes. Maybe in the future down the road some I'll invest in the time & money in making my own wood screens. But I figured this a cheaper alternative & no building necessary. Does say a 30 mesh or 50 mesh differ that much from the 40 mesh & possibly swap out the 80 mesh u mentioned for the 70 mesh available in the sizes listed above. Can I get buy with the few off sizes for the meantime will they suit my purposes just being a total beginner? I know optimally why the sizes exist. For sizing purposes but for mixing would they work? I look forward to hearing back from you. Thanks Dyl

[Carbon796]

4,8,12,20,30 will be the most useful.

3,6,12,20,30 are my preference.

 

The 50,70,100 are really so fine you won't really get a whole lot of practical use from them. For general fireworks building.

 

I have a 60 mesh screen, probably haven't used it in 7 years or more.

 

20 mesh is the generally recommended size for screen mixing. I usually use a 30 mesh. So you could easily get by, with just your first 4 screen choices. If you dont want to spend the money, on a fifth screen. If your sole purpose is just a comp mixing screen, you really only need one. The rest are for grading/sizing/processing, granulated material.

 

Any finer and the mixing time and effort go up considerably. So does the induced friction, for working the comp through such a fine screen.

 

3 mesh is the recommended size for screen granulating Polverone and BP. To produce an end product, that closest resembles 2FA. Once screened properly.

 

Coarse BP/polverone -3+6

Medium BP/polverone -6+12

Fine BP/polverone -12+20

 

- and + screen sizes. The - means the material will fall through that screen size. And the + means the material will sit on top of that screen size.

Edited June 29, 2020 by Carbon796

[Arthur]

Don't overthink it! Screens from 2 to 20 mesh are for grading BP, a couple finer than that are for ingredient sizing. I once found 300 mesh essential but only used it once. You will always have some you use to worn out and some that you can remember what you sieved through them.

 

NEVER use sieves for both chlorate and sulphur comps. Chlorate sieves should be ONLY used for chlorate comps.

 

Buy mesh if it's available, use a soldering iron to melt/push the mesh into a takeaway meal tray.

[davidh]

Don't overthink it! Screens from 2 to 20 mesh are for grading BP, a couple finer than that are for ingredient sizing. I once found 300 mesh essential but only used it once. You will always have some you use to worn out and some that you can remember what you sieved through them.

 

NEVER use sieves for both chlorate and sulphur comps. Chlorate sieves should be ONLY used for chlorate comps.

 

Buy mesh if it's available, use a soldering iron to melt/push the mesh into a takeaway meal tray.

You can use the same screens for chlorate and sulfur. Make sure you wash them well between.

 

You CAN NOT use the same screens for chlorate and ammonium perchlorate!!! Or any tools for that matter, without cleaning them like your life depended on it!

Edited June 29, 2020 by davidh

[davidh]

Davidh, so given the screen choices I have what would be your 5 to work with. I'm aware I can buy screens to make them but I don't have the wood working tools. To build the boxes. Maybe in the future down the road some I'll invest in the time & money in making my own wood screens. But I figured this a cheaper alternative & no building necessary. Does say a 30 mesh or 50 mesh differ that much from the 40 mesh & possibly swap out the 80 mesh u mentioned for the 70 mesh available in the sizes listed above. Can I get buy with the few off sizes for the meantime will they suit my purposes just being a total beginner? I know optimally why the sizes exist. For sizing purposes but for mixing would they work? I look forward to hearing back from you. Thanks Dyl

I didn't say anything about wood screening boxes. I prefer bucket screens. All you need for them is something to cut the bucket bottom off, melt the screen into the plastic, and then trim the screen.

 

Exact sizes simply don't matter for screening purposes. Those sizes are fine. I would get the 50, and flip a coin between getting the 30 and 70.

Edited June 29, 2020 by davidh

[Mumbles]

There is one advantage to using a finer screen, like a 60 mesh that I've found. 50 or 70 would probably also work. Some of our chemicals have debris in them. I'm speaking most specifically about red gum and Parlon. Red gum, depending on the grade, often has small amounts of sand, bark chips, etc. Parlon, depending on the brand, also often has larger pieces. I generally passed my colored compositions through this mesh once to remove this unwanted materials. I don't know if the red gum made much of a difference, but I didn't notice a difference when using parlon. The coarse, larger parlon pieces, can leave a thin incandescent trail of orange-ish particles that I personally find very irritating.

 

There are other ways to remove this junk or use other/better materials, but I found screening to be the most straight forward for what I had.

[Siegmund]

If I were buying expensive screen sets, I'd emphasize the sizes from >20 to 60 mesh: for me it's just too easy to buy hardware cloth, kitchen strainers, and window screen to cover the sizes from 4 to 16.

 

Admittedly I would have fewer scratches on my arms if I had bothered to put something along the edge of my hardware cloth

[Arthur]

As mesh comes in squares here, I've found (in Asda/|Walmart) 12" square plastic kitchen boxes about 4" high, with lids and 4" square sandwich boxes with lids. These make large or small nesting stacks of sieves, use a plain tray at the bottom and a lid on the top one.

 

One set of mesh sizes for grading BP one set for mixing comps through, maybe a really fine small one for occasional use (yes I once had a comp that would not work bigger than 200 mesh so it had to be made through a 250 mesh sieve.

[Dylman]

DavidH, Sorry I said you were talking about wood screens. I'm mistaken, it must've been a conversation I was having with someone else about making the wood ones. I've spoken to a few people about the screens and which route would be best. All this new info to take in can be confusing. Thanks for all the recommendations from the group I appreciate your experience in these matters. I'd like to avoid mistakes especially when it comes to spending money on stuff I might not need or use regularly. Thanks, Dyl