Black match

[SharkWhisperer]

Is moisture the actual problem, or are you milling your BP comp too long. Have you actually tested your individual chems, to see if you even have a moisture issue. Dry chems will still clump up, if milled too long. If you don't want your comp to clump up. Stop milling it, before it does. In pyro you just can't expect stuff to work. Or, assume that it will. You have to make your chems, comp, materials, processes, and techniques. Work for you, in your environment.

With respect, while I appreciate the observation, I disagree with the conclusion/causation. I have done extended BP milling (days for some new charcoal tests) and the only clumping I've ever had has been directly attributable, retrospectively, to damp, even slightly damp chems (nitrate will pick up a % or 2 of moisture that is often ignored). With nitrate/charcoal pre-drying, I have never again experienced clumping issues at all, even with extended milling times and I've gone out to 3 days before (uhh, did I forget to put the mill on a timer...?), with different mill setups, in deep-south outside humidity. All my mill jars are rubber lined, if that matters, and that's generally using lead media.

 

Before predrying chems, I'd occasionally get clumping beginning after a few hours, only worsening with additional milling time. To the point that I had to use a lot of force to scrape the clumped BP chunks out--that shit was as tough as dextrin-bound.

 

And I don't think OP's been milling beyond 12h max, if I recall earlier post; actually, I recall much lesser milling times, where clumping most definitely should not be an issue.

 

I fully expect that OP will report back excellent success after drying his chems prior to milling.

Edited October 11, 2020 by SharkWhisperer

[SignalKanboom]

I will post more later, but absolutely not milled too long. The milking jar has large gaps where the pipe is joined with the cap and it clumps and fills those in. No matter how hard I try to get it all out it is tough. I need to find a way to dry and closed object with crevices. I am positive it is due to media, jar, and comps being wet.

[Bourbon]

I apologize if my comment about room temp was misleading.

 

Not in the direct sun, or ice cold, but "Room Temp" as a reference:

 

Colloquially, room temperature is the range of air temperatures that most people prefer for indoor settings, which feel comfortable when wearing typical indoor clothing. Human comfort can extend beyond this range depending on humidity, air circulation and other factors. In certain fields, like science and engineering, and within a particular context, room temperature can mean different agreed-on ranges. In contrast, ambient temperature is the actual temperature of the air (or other medium and surroundings) in any particular place, as measured by a thermometer. It may be very different from usual room temperature, for example an unheated room in winter.

 

Room temperature definition: a comfortable temperature range indoors, usually considered to be 68 to 77°F (20 to 25°C). Not hot or cold.

 

For instance. Cold media and jars, may pull moisture as they warm from the air, while your putting the comp or chem in.

 

It sounds like you have a good understanding of what the problem is from your last post.

[SharkWhisperer]

I will post more later, but absolutely not milled too long. The milking jar has large gaps where the pipe is joined with the cap and it clumps and fills those in. No matter how hard I try to get it all out it is tough. I need to find a way to dry and closed object with crevices. I am positive it is due to media, jar, and comps being wet.

Not a fan of any hidden crevices or open threads in a milling jar. I'd expect that a few bumps of milling media would pack those gaps full of unmilled comp that would remain there, unmilled, for the duration of your spinning. Maybe it's not a large fraction of your total volume so doesn't really matter (apart from clumping, which would bug the crap outta me). Maybe you could screen out larger lesser-milled particles after milling but why have the hassle? Maybe you could wrap the bottom lid threads with teflon tape before every mill session to keep comp out of the threads--it's just BP but it'd make me cringe to know I was grinding active comp within the threads every time I opened my mill. Yikes. How to remove the gaps between the cap and the pipe? Seems necessary, too. You really do not want any hiding spots for comp to get rammed into or where it can escape milling.

 

The hard clumping I'm less worried about--pretty sure like many have said that that'll go away when you dry your starting chems. Hell, the stuff that gets packed into the gaps might also fall back into your main volume if it's bone dry... Those threads catching BP kinda worries me though...grind, grind, grind, friction, friction, friction...I'm usually pretty nonchalant with BP, respectful but not ever paranoid, but that grind, grind, grind when opening the mill would up the pucker factor quite a bit... for me, at least.

[SignalKanboom]

It is a sponenburgh jar, a pvc pipe with a cap glued on one end and a reducer starting as the same diameter as the cap on the other end. I put one of those wingnut expanding gaskets in for easy loading and unloading. I dont tighten it much in case of accident hopefully the cap blows off and All the pressure is relieved. Imagine sliding a pipe into a flush cap there is no cap, but because I dont know if there is a cap that is flush the crevice comes from the end of the pipe to the taper of the different connections.

 

Shark, you like using the oven and that answer my other questions. I was wondering if I should get into desiccants, or just dry my comps with a toaster oven.

 

As for drying a jar, any suggestions?

[SignalKanboom]

I understood what you were saying bourbon. Nice clarification though, I was cracking up. No offense to carbon either I appreciate that attention to detail. The threads I have seen where people ask certain questions make you realize how lucky you are to not need to ask those questions.

 

Maybe, Im one of those people too though, I dont know. This all should have been pretty simple stuff, but very minute variables cause very drastic changes it outcome. I know these are chemicals, but I didnt think it would be this hard to ball mill some black powder.

[SharkWhisperer]

It is a sponenburgh jar, a pvc pipe with a cap glued on one end and a reducer starting as the same diameter as the cap on the other end. I put one of those wingnut expanding gaskets in for easy loading and unloading. I dont tighten it much in case of accident hopefully the cap blows off and All the pressure is relieved. Imagine sliding a pipe into a flush cap there is no cap, but because I dont know if there is a cap that is flush the crevice comes from the end of the pipe to the taper of the different connections.

 

Shark, you like using the oven and that answer my other questions. I was wondering if I should get into desiccants, or just dry my comps with a toaster oven.

 

As for drying a jar, any suggestions?

I dry my chems (charcoal, potassium and strontium nitrates only, but every time) and then store them with dessicant packets, in relatively airtight screwtop polypropylene jars. I highlight "relatively". If no dessicant, they eventually start to absorb water again. Probably right away, but I've never really worried or timed it--after a month or so, I've seen clumping again if I didn't add silica packets (there's plenty of other types--I like the color changing variety). Clumping is obnoxious as hell but never occurs anymore because nitrate and charcoal both get silica gel packets right after drying. If the color indicators don't say water-saturated silica, then the comps are pretty much guaranteed not to clump in the mill. BP gets dessicant packs, too. All types of BP. Commercial BP is protected from moisture by formulation and manufacture, but I don't use much. My charcoal and nitrates get cooked. My charcoal, nitrates, BP, BM, and most red comp powders/stars all get dessicated. Always. A couple of $ in re-usable silica packets saves enormous headaches. Dry and dessicate--problem solved forever...

 

I only wipe and air-dry jars and media. Never been an issue for me.

Edited October 12, 2020 by SharkWhisperer

[SignalKanboom]

I will do both of those things. Shark is your jar smooth and made for milling though (not homemade)?

[justvisiting]

I'm going to go out on a limb and suggest your problem might be static cling. You say "sulfur charcoal". I don't know that the blend will necessarily cling, but plain sulfur sure does! I had to mill sulfur prills and I got a huge problem with static cling. Next time, I gave the jar and contents a couple of quick shots of Static Guard spray. No more cling.

[SharkWhisperer]

I'm going to go out on a limb and suggest your problem might be static cling. You say "sulfur charcoal". I don't know that the blend will necessarily cling, but plain sulfur sure does! I had to mill sulfur prills and I got a huge problem with static cling. Next time, I gave the jar and contents a couple of quick shots of Static Guard spray. No more cling.

JViz, maybe static an issue also, but he's been getting clumping to rock-hard so that it's difficult to even get his comp off the jar wall and out of the barrel. Seems a little more than "clingy" sulfur :=}

 

Gotta check what's in my StaticGuard--maybe it'd make a decent fuel supplement !

 

Edit: Techwalla, whose articles usually seem like they're written by 5th graders, says StaticGuard is just deionized water and alcohol. The MSDS says similar. Just warnings re ethanol content as a flammable aerosol (and unidentified perfume as odor) and not much else. The MSDS says it's density is 0.78-0.80 g/cc. Guess what! The density of pure EtOH is 0.785 at 25C and 0.804 at 3C, just above freezing. Bwaah hah hah, we've all been getting jacked for $$$ on Static Guard when it's just perfumed Everclear!!!!!

 

Now I feel really stupid. A liter of the nastiest rotgut 95% EtOH grain alcohol at the local liquor store is around $15. Guess it makes great Static Guard in addition to hand sanitizer. Sheesh... Never buying it again...

Edited October 12, 2020 by SharkWhisperer

[Mumbles]

It's more than just water and alcohol. MSDS are only required to list the hazardous components, but some will list everything out of habit. Most brands will contain quaternary ammonium compounds as the actual static dissociative agent. https://beta.lakeland.edu/AboutUs/MSDS/PDFs/2731/Static%20Guard%20Anti-Static%20Spray%20(B-G%20Foods)%203-18-15.pdf

 

Every brand is different, but those sorts of things are also found in things like fabric softener and some cleaners. They're a popular DIY alternative that a lot of people who don't understand science tout as a healthier, safer, organic alternative.

 

More on topic, the gap between the PVC pipe and the end caps, especially at the closed end, are the one part of the Sponnenburgh design I'm the least a fan of. They are cheap and easily available though. There are a lot of designs that work for jars. If you're handy at wood working, there are some other designs I could help describe that solve some of the issues. My gut assumption is that your charcoal is damp. You may want to try to spread it out and leave it in the sun as a first step.

[justvisiting]

Maybe it is more than static cling. Maybe the cling happens first, and continued milling (perhaps with the aid of moisture) packs the particles more densely onto the surfaces they clung to. Easy enough to find out. Without going back through everything that's been written about this issue, I don't recall reading the size of the 'Sponenjar'. With a 6" diameter jar, I would mill 500 grams of charcoal. With a super light charcoal like balsa, I would fill the jar with as much charcoal as would fit, mill for a few minutes, add the rest, and finish the mill cycle. I mill my charcoals for a long time (4-6 hours), because I make single-component-milled BP. If I were to mill BP in that same jar, I'd use 750 grams for a batch. If the powder didn't need to be too fast, or I'm using the jar to blend charcoal star comps, I'd load it with 1000 grams.

 

The Static Guard most certainly has a lot more in it than alcohol and perfume. I'm very sensitive to it. Something in it causes me to have a very powerful feeling that my lungs are being filled, and making me feel short of breath. I use it outside, or hold my breath. Lots of old hands regularly use Static Guard on their screens, clothes, gloves, etc... so I assume that any concerns about its use may have already been addressed. It would probably be prudent not to use it with any AP-containing comps, or with any chlorate-containing comps- and I don't.

 

The 'rule' about loading mill jars with a 1/4 fill of charge is more of a general suggestion, IMO. The rule does not apply when milling charcoal. The rule does not apply when milling BP with unmilled ERC charcoal, or with charcoal simply run through a waste disposer. The rule only applies when milling powders that do not change volume appreciably when milled. Milling charcoal is very hard on lead media, and adds significant amount of lead to the finished product. My previous experiments seem to indicate that this contamination can affect performance to some degree. For milling just charcoal, I like stainless steel in small sizes. I find ceramic to be too light to do a great job.

 

Considering the gaps between the pipe walls and the end fittings, I wonder why the gaps are there. Was the pipe not cut square? Were the fittings not pushed on all the way? Was the solvent cement not applied properly? I have made plenty of mess using PVC solvent cement. One time I decided to use bath tub silicone instead of solvent cement. I used the kind that releases acetic acid upon curing. It wipes on easily, the excess wipes off easily, and it makes a nice filet in the areas where the fittings and pipe meet. I was told by a guru that it would never work, and that the silicone had no strength for this task. It works perfectly. Any excess that gets on the jar will exfoliate in the first run or two.

 

As far as worrying about the strength of the lid closure causing a larger explosion if a spark occurs, I don't see that as a concern. The mill is supposed to be properly barricaded, so that IF an explosion occurred, there would be no injuries. No humans or animals to get hit with sharp shards of PVC, no humans or animals to get hit by flying lead, no humans to call the cops if it does go boom. Milling live BP is best done after dark, and preferably when it's raining (where I live). If the mill goes boom at night, the smoke won't be seen, pointing like a big, accusatory finger at the source. Just as a cannon makes a boom whether or not it has a cannonball in it, I'm (pretty) sure a mill jar with a weak lid won't be more forgiving in an ignition event than a lid that is secured so it can't leak. I use LDPE test caps, held on with hose clamps. I've never had a leak in a lot of years.

 

Once the OP solves his moisture and possible static issue, he'd probably benefit from double component milling.

[Mumbles]

The gap toward the closed end comes from the end cap itself. The pipe just doesn't seat flush up against the end. They have a slightly domed end, so at best, there would be a slight cavity from the dome. In my experience, there is maybe a 1/4" "cavity" toward the closed end from this, and the curve of the dome, and all that. I believe they make flat end caps too, but I haven't seen a mill jar made with one up close to say if they're any better. The cavity toward the front near the reducer is not as big of a problem in my experience. It's really more of a lip from the wall thickness of the pipe. Maybe I got lucky, or my floor was tilted, but I never really had any clumping up at the front of the jar for the most part.

[pyrokid]

Can anyone report on the performance of SGRS in black match slurry? I have never used it, but apparently it has the property of keeping insoluble elements better suspended in a slurry - a property that makes it well suited to the toro method of star production.

[justvisiting]

I made black match with SGRS once. I found it to be somewhat crumbly. As I mentioned 'somewhere', CMC is used to keep the slurry from separating, and is used at 1% in the slurry, with 3% dextrin to act as binder. That's what I use now. The dextrin-bound match is certainly prone to absorbing moisture on a dewy night.

[SharkWhisperer]

The dextrin-bound match is certainly prone to absorbing moisture on a dewy night.

Yup. That's why I typically wrap my BM in paper or foil and store it in long cylindrical shipping/poster tubes with a few desiccant packets. Stores fine for years if desiccant packs checked occasionally--maybe unnecessary in low-humidity regions, but cheap insurance.