Shitty Lift Powder? Create a diaphragm.

[Bju90]

As a beginner, this was my second batch of BP and stars/comets I had made. BP was made from lump charcoal pulverised in a cheap drink blender and screen mixed. 

I had made everything just before new years and was hoping to put on a small display for the family. After testing the day of, I realised the BP was not hot enough to lift anything whatsoever.

Fortunately I had read recently read about microstar mines on skylighter being shot without any lift powder by using masking tape to create a diaphragm at the top of the tube, allowing the pressure from the star ignition to build up. Which reminded me of hypersonic test facility where I studied, which used a large diaphragm designed to rupture at a very high pressure, to fire a hypersonic pulse at a model rocket.

The video below is the result. Some mines and comets shot from 21mm ID HDPE pipe using a tsp of slow BP and two pieces of masking tape across the exit to create a diaphragm.

Thought this might help out others who live in a country where you can’t buy sporting powder and are struggling to make lift powder.

 

[Arthur]

One of the first necessities of pyro is a good supply of good BP. Don't waste time, materials and the neighbours' patience by finding work-arounds for being too lazy to make decent BP, and have (just) enough of a coarse grade, and a fine grade properly milled pressed and corned BP.

The better your fireworks, the more likely people are to regard them as professionally made fireworks, and not bother you.

Yes, often it's the apparently insignificant things like the disc of card with a hole or two between lift and stars, and the disc of paper over the open end of the tube to help pressure build to let movement begin.

[Bju90]

Being too lazy? This was the second batch I had made, am very time poor and only have small windows where I can test anything. By being “lazy” I was able to still get the desired result, gather more data on how the stars and comets would perform and not have two extremely disappointed kids on new years.

Ive since procured a ball mall, some willow charcoal sticks and able to produce a much quicker bp I can now use as lift.

For those just starting out on their first or second batch, without a ball mill etc, is it really so bad to be able to produce the desired effect by being “lazy”?

Look at the Turbo pyro book. It assumes the person reading it is “Lazy” and will buy their lift powder instead of making it. What’s so wrong with a method that allows them to continue if they don’t have access to purchasing BP? I wouldn’t call it lazy or a work around, it’s a mechanical method to allow the build up and release of pressure in a relatively constant manner. It’s quick, takes very little skill and uses material that anyone should already have. 

By employing this method you could produce most things in the turbo pyro book without having to make/buy hot powder at all. For someone starting out, why is that such a bad thing? Work smarter, not harder.

 

 

[DavidF]

I appreciate your efforts. There are lots of us here that are not gurus. Learning pyro keeps us humble  Humility is a virtue

Keep at it bro!

Edited February 15 by DavidF
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[Bju90]

@Arthur I’m a bit confused by the message you are trying to deliver. As someone new here it feels dismissive without any technical feedback as to why this method shouldn’t be used. The result feels like it’s shut down potential technical discussion on the actual method instead of fostering intelligent discussion.

What is defined as “good” BP? I’ve read posts here where people will have a hot BP and a slower mix for different purposes. So does BP have to be fast to be considered “good”? 

Id like to make a good quality product, I’ve included some videos of the results. If you have any constructive feedback about the results and improving them I’m honestly interested in any constructive feedback. If the method I’ve used to get the necessary lift is unsafe or has any undesirable repercussions, again I’m genuinely interested. 
 

im only looking to make smaller size items and now that I think about it, using this method I don’t know if I would even technically need a really hot powder. By removing this need I reduce complexity.

Considering the underlying mechanics, putting some tape across the outlet like this to build up case pressure vs using a hotter BP seems conceptually very similar to the response @Mumbles made in the post below this about pasted layers on an aerial shell vs break charge/boosting.

Edited February 16 by Bju90

[DavidF]

Just recently we had a guy that didn't know how to make a can of charcoal for BP, but he got the help he needed. Nobody was dismissive with that guy. Can't remember who it was, but there are a lot of beginners in our bunch. I agree that being dismissive of newbies serves no (good) purpose. Maybe Arthur will tell us how he makes and grades his charcoal and BP, so we can copy that method for guaranteed results

If he doesn't help you, one of us can try

EDITED TO ADD:

 

This might be helpful to you for next time.

Edited February 16 by DavidF
Additional content

[gizmothegecko]

How I Make My Charcoal for Lift Charges

First, I gather sticks about 1–2 cm in diameter, typically from a willow tree in my backyard. The best type of wood will depend on what’s available in your area. I strip the bark off to remove impurities, then bake the sticks in an oven at 200°F for a couple of hours. This step isn’t necessary, but it significantly reduces the smoke produced during carbonization. Cracking the oven door slightly helps moisture escape and prevents excessive smoke buildup in the kitchen.

Next, I load the dried sticks into a paint can from my local hardware store and heat it in my barbecue at around 600°F. I monitor the temperature using the built-in thermometer on the barbecue. I usually crack the lid slightly to allow smoke to escape, though this isn't needed if your barbecue has a vent. The process takes about 45 minutes, and it's done once the smoke stops coming out of the can.

Once done, I let the container cool overnight before crushing the charcoal and running it through my ball mill to get a fine, high-quality powder.

You can also use an open fire for this process, but be careful—it’s easy to overheat the can and accidentally turn your sticks into ash instead of charcoal. That’s why I prefer using a barbecue: it gives me much more control over the heat, doesn't require constant tending, and works regardless of weather conditions.

As a side note, I wouldn’t recommend using willow charcoal for making BP. It often contains impurities like starch or gum that act as binders, may have higher ash content, and is much more expensive than making your own willow charcoal.

Lastly, I’d suggest using a proper lift charge rather than relying solely on internal pressure buildup. With a lift charge, you have much more control over the height and can achieve more consistent results. That said, there’s no harm in experimenting with both methods to see which works best for you. Fireworks are all about trial and error, so keep refining your process!

Let me know if you have any questions—I’d be happy to help

Edited February 16 by gizmothegecko
grammar

[Telefunken]

Hi! I usually make several pounds of eastern red cedar charcoal while burning brush and leaves in the fall, personally I just toss everything in a ball mill and let it run until I wake up the next morning. I know it doesn't seem that big of a deal but make sure you mill your powder in an isolated area away from people, pets, and property. Have fun be safe! And the diaphragm does makes sense even though many people will argue with me haha.  

[Bju90]

Thanks, I do appreciate everyone trying to be helpful.

I think we might be getting a little off topic though from what I originally intended to discuss in this topic. I did waffle on a bit in my original post, my bad. I find it a little hard to communicate effectively and get the most out of forums, being a bit Nuerospicy. 

My intent was to discuss the potential of using something like masking tape as a diaphragm to help create lift, whether anyone has had experience with this or can see any downfalls to the idea.

I think Arthurs response raises the question though, do you NEED a hot powder to participate in pyro? Sure if you want to progress, then having a ball mill and access to fast charcoals is a necessity. Starting out though, if you can make a reasonable quality powder with lump charcoal, a drinks/coffee grinder and screen mixing there are still lots of things you can make, no? Having success lifting small payloads with a slower powder via the diaphragm method, this allows you to produce even more before having to spend the money and time of getting a ball mill, learning to make charcoal, storing the equipment, safe storage and processing procedures for milling etc etc. 

I would love nothing more than to take the time and produce everything myself from scratch and perfect every step. However with work, two kids and a very small worspace limiting how much I can store, I choose to reduce complexity and minimise manual labour in the beginning. Then take the time as I have it to learn a new part of the process.  As long as the result is safe and still of a reasonable quality.

For what it is worth, since this story I have procured a ball mall and a source for small amounts of willow charcoal and have been succesful at making a hot powder.

 

 

Edited Tuesday at 02:24 AM by Bju90

[Arthur]

No you do not need perfect powder for fireworks! Powder that is slow suits rockets and fountains and every beginner thinks their powder is great -'til they meet better powder. A basic test for powder is to put a ball in a mortar with lift powder and time the flight from bang to bump on the ground. Something like a cricket ball or a baseball is typical. With better powder the ball flies for a longer time. 

The problem with weak powder is that it's hard to diagnose firework problems and malfunctions if the powder is too slow, also if the powder is slow shells burst too near the ground and are not safe or entertaining. As a start to quality fireworking you need quality powder so that you can say "BP" and everyone knows what you mean..

I've heard of people making charcoal in Golden Syrup cans, coffee cans, up to oil drums. Some people use propane some use a fire of waste wood or coal. One YT video showed someone making charcoal in a "baked bean can" with a slightly larger can over the top all done over a wood fire in a workshop fireplace.

[Mumbles]

One of the biggest dilemmas in our hobby is that most would suggest starting with small devices to get some experience and learn the trade, but small devices often require the hottest powder and leave much smaller margins of error. This is especially true with lift powder.

There's nothing wrong with using masking tape to seal things up and help build pressure. Masking tape can have a tendency to smolder though, so just keep an eye out and avoid shooting near dry debris. People have used all sorts of things to the same effect. I like paper discs or wads above the mine. It has the added benefit for me that it keeps everything secure and in place if I'm testing or shooting somewhere different from where I built it.

Just a general suggestion to anyone making charcoal. Try to seal up the can after you're done cooking, and ash tends to be less of a problem. With coffee cans, or paint cans or anything else on the handheld size, a couple of sheets of aluminum foil over the top works just fine if you don't have a solid lid available. It's not going to entirely keep air out, but it slows it down considerably.