272 replies to this topic

[BurlHorse]

Well, I use different media for different Chems, and ceramic Media is fine, easy to clean, but does have it's own set of disadvantages.....

1) It's porous, Yes, I know what "They" say, none the less, it is porous and there fore a thorough Boiling with a few water changes, not to mention Drying time, are needed to clean it between chemicals. After it's Clean, just put about 50 or sixty golf ball sized ones on a cookie sheet and into the oven they go, low heat, 2 hours, and your ready to mill again.

1a) I find Hardened Ceramic "Jawbreakers" work great for milling Oxidizers to dust, and since the media is white, hey, your chems stay pretty. Most oxidizers don't have much of a stickyness factor to them, cept maybe Strontium Nitrate, which I find the hardest one to completely clean from this kind of media.

2) Cost, I don't know what your paying for them, but I paid a pretty good penny for mine and treat the Media with care, Cracked or gouged pieces are canned as they tend to ruin other pieces.

Guess thats about it, will it spark, Probably, almost anything will under the right conditions. I say pay attention to the weather when you are planning to process or mill, Humidity 55 to 70 percent you and your mill will live alot longer. Stay Clean to Stay Green......

Regards,

Bear

[bernie]

I must have gotten a better deal on my media than you did. My ceramic media lives in different labeled jars which eliminates any cleaning issues

[BurlHorse]

Hey Bernie,

Well, When I got mine, Media I Mean...Many Mnay Moons Ago.. I was a newbie, Bought ALOT of it and paid dearly for not knowing better. Your Idea of Storing it in different Jars has me banging my head against the desk.....I have enough of the media to use dedicated media for every chemical in the shed.....Silly 'Ol Bear...ha-ha, Thanks for the tip!
I was more or less gearing that post to the lesser equipped folks out there. I've read alot of posts in this thread and just wanted to give up my humble 2 pence.

Some of the things I've read in this thread really make me wonder about a couple of things.

If the Brass tube filled with lead Media is being used, and I assume a PVC Mill Jar is being used, how much PVC is being introduced to the Formula from the brass eating up the Mill Jar......, unassuming chlorine donor haha. Same with the Brass Nuts Filled with lead.

Copper tubing filled with lead....... Why did that red star comp come out a Magenta color? Did'nt I read somewhere that Copper Chlorate was a real hum dinger.....I.E; Sensitive HE.....Don't mill Potassium Chlorate with it....I don't know the molecular possibilities, but I won't be finding out by accident

The list go's on and no slam intended to anyone but stick to the basics keep all media clean, Mills or grinders seperate for oxy's, Fuels and "Other" and all should be fine.

Regards, Stay Green

Bear

[lord_dranack]

Got my 2lb mill today and am as I write milling a batch of finest willow charcoal!
No more tedious mortar and pestle work or H3 lift powders for me!

I know you shouldn't overload mills as it is less effective, but on the instructions (for tumble polishing) it said to make sure the mill was 3/4 full!

Edited by lord_dranack, 21 January 2004 - 07:29 PM.

[Richard H]

I know you shouldn't overload mills as it is less effective, but on the instructions (for tumble polishing) it said to make sure the mill was 3/4 full!

Well, for pyro your mill should be charged with 1/4 of material and 2/4 of media, so effectively the mill will be 3/4 full.

[dfk]

Well, for pyro your mill should be charged with 1/4 of material and 2/4 of media, so effectively the mill will be 3/4 full.

Maybe this is why I have to mill my material for days. My milling jar isn't even covered on the bottom with media. 2/3's media is this true??

[BigG]

No, 2/4 milling media.... or 1/2. in addition to 1/4 compo, which bring you to 3/4 full jar.

[dfk]

My mistake but you missed the point, thats still more than i have.

[Rhodri]

Hi DFK

Are you saying that you have more material than media?

[Matt]

I have a mate in adelaide who shall remain nameless who had a 6 or so inch jar and had about 7 sinkers for media. hehe, I told him what was wrong and now he makes 500g batches of good BP, kinda makes me angry as I only do 100g.

-Matt

[dfk]

Are you saying that you have more material than media?

Hey Rhodri

Ya I have alot more material than media. You guys are talking about volume not weight right. My media dosnt even cover the bottom of my 3lb jar. If is true this bugs because this is how I bought it and how I've been milling for at least a year now.

I got my mill from United Nuclear and the guy who sold it to me was telling me somthing like theres some mathematical way to figure the number of balls for most efficiant grind: The media was included with the mill and I was new so I went along with it?

[Matt]

well as a lot have posts have pointed out, the jar needs to be HALF full of media and 1/4 powder.

-Matt

[Phoenix]

I think I read on rec.pyrotechnics that United Nuclear mills come with far too little media, and you need to buy or make extra.

This is one of those rare occasions in pyrotechnics where things are measured by VOLUME not MASS. You should fill the jar with media up to the half way mark (standing up), then add up to 1/4 of the jar's volume of material. If you load more, it will take longer to grind, and visa versa. Loading by mass doesn't really work, as it's the volume that matters and this will obviously change with different sized media, and different materials.

My mill jar isn't actually half full with lead, it's about 3/8 with 15x20mm cylinders, but this works fine and will have BP milled to dust in 4 hours (starting with coffee grinder charcoal, prilled sulphur and sugary potassium nitrate). However, when I mill BP, I load my mill with 100g max of material, in the interest of limiting the effects of an explosion. (I know BP mills very rarely explode, but I prefer to design my safety guidelines on what whould happen in the worst case scenario, rather than the best.)

According to the calculator on passfire, I could fit about two hundred and something grams of BP (given average density materials) in my jar (which is a 125mm section of 4" PVC pipe.), so loaded to the maximum amount (1/4) it would take longer.

Another point is that my new mill uses the same amount of media as my old one. The original mill had a 20x30 cm paint can as the jar. Like yours, the media didn't even cover the bottom of this and it took _ages_ to do anything. Now that I have a smaller jar, the same amount of media will mill the same amont of powder in far less time. Hope this helped...

Edited by Phoenix, 24 January 2004 - 06:05 PM.

[Rhodri]

Excellent reply my Firey Friend!

Good advice there too "Build small and think big".

[Phoenix]

Thanks, I do my best :-)