What did you do today in pyro?

[OldMarine]

Love Paul's videos!

[Sulphurstan]

Nice to know about the willow charcoal. I might try it some day

 

On another note, you will also get better BP if you mill the KNO3 with the other ingredients.

If you worry about the hazard of having a drum full of explosives, you can also mill the KNO3 seperately before mixing as usual.

 

The CIA-method is said to lower the overall quality of BP, due to some KNO3 being "lost" in the water. As someone who started with the CIA-method myself, I confirm that.

It's better to use less water and a little more work. I use 20% water with 10% dextrin. That equals to 2% dextrin in the final composition.

Here's a helpful example of how to wet BP with less water, by Bangkok Pyro:

https://www.youtube.com/watch?v=q6gE8wkTPdE

Ubehage,

 

Regarding the mixing of the 3 ingerdients together, I did it and result is obviously very satisfying, but I'm still not confident, when I read what happened to some experienced members of this forum with BP ball milling, I try to get the best out milling C and S on one side, and kno3 on the other side.

 

Thank you for the video of bangkokpyro, i'll definitevely have a look! I was really thinking about the fact of loosing some kno3 in the water absorbed by the iso propanol (if I understand right, what you mean), and your post just confirm my doubts.

 

Anyway, I guess I've reached a good level of burn rate for my needs with BP. (needs some more testing and repeatability to confirm)

[lloyd]

First, let me say that almost all ball milling accidents have been caused by one of two primary 'diversions' from what we've collectively decided to be "normal practice". I've been (shall we say) rather deeply involved in ball milling since 1992. <grin>

 

1) Folks have (rarely) used sparking milling media; stones, steel (other than stainless steel alloys), and some ceramics are known to have caused accidents.

2) Most such accidents have been caused by "process greed"... trying to get as much ground in one step as possible. The large-diameter mill jars and heavy media they've used have increased the milling forces to the point where ignition was probable; and it's happened that way a number of times.

 

With milling jars under 10" in diameter, and with lead media, such accidents have rarely occurred. If the mill is in a 'safe' location - barricaded and away from dwellings and process areas - then the only loss was the mill and/or its jar.

 

Properly done, ball milling is a "relatively safe" procedure, even on the full mixture.

 

Now... that said, David Forster has done extensive experiments with ball milling non-explosive mixtures, then combining them after milling. He's had VERY good success with the method, obtaining powders stronger and faster than stock Goex powders.

 

You do yourself a great disservice if you do not read his posts. I believe he goes by "DavidF" here.

 

Lloyd

Edited February 17, 2017 by lloyd

[Voryon]

Cut some small nitrate red strobe stars using the "nitrate baggy" method.

[OldMarine]

Good looking cubes!

[Voryon]

Thanks OM, I am so happy that I found this method as it so greatly improves cutting NC bound stars without the issue of unwanted fast evaporating acetone. These little cubes have now been primed and wait for the water to evaporate.

[Voryon]

I gave my first plastic can shell a try, 2" filled with Crackling Stars and boosted with 3g Flash. Quite surprised how easy and fast this shell was made. Shell weights 110g, lift is 15g BP.

[Voryon]

Shhhh... 3g of hot flash were far too much, it became a salute with 3 microstars that survived. As I've read that plastic shells build up less pressure I thought it would need a little more, I was wrong. Still impressive how far those three stars travelled especially considering that they were just a few mm in diameter. Wondering if there are stars/primes that could survive such a strong opening, this could make a 2" that might be mistaken for a ~3-4". Edited March 5, 2017 by Voryon

[lloyd]

Finished up the press block and 72 top/bottom rods for a 36-position lance press. Just got to make the rod bolster plates, the loading/drop tray, and affix the guides.

 

LLoyd

[OldMarine]

I did nothing but clean and organize the shed but I'm doing my pyro vicariously through Lloyd today!

We kicked butt!

Edited March 6, 2017 by OldMarine

[Sulphurstan]

Messed up a BP batch with bad kno3 amount, was very sad, and thought "throw away or try to pimp this poor mix in something better?" thus added 0-100 micrometer titanium and it turned out to be fabulous as silver tailed go getters. Happy 😁 Edited March 6, 2017 by Sulphurstan

[lloyd]

Sulfurstan,

 

If you KNOW the amount by which you mis-measured, I have a formula (in Excel) that will allow you to modify one formula into another of different proportions. (and if you know the INTENDED formula, and know that you only mis-measured one item, and know the mass of the resultant mixture, you can do this)

 

It permits you to enter the original formula and the desired one, then gives the amounts of chemicals to add in order to get to the desired one.

 

But that said, good on you for 'converting' it to something useful.

 

Lloyd

Edited March 6, 2017 by lloyd

[Sulphurstan]

Lloyd. That's sound good.

 

But does your excel file also helps in that following case? guess not, 1 unknown term in excess in the equation :-(

 

In my previous case (I'm not too proud of admiting it), the plan was to make a new batch of BP by damped screengranulation, with a rest of dusty BP, added with "15C+10S" ball-milled together and KNO3 ball-milled separately to sum up to approx 150 grams.

 

- Rest of dusty BP was NOT weighted

- "15C + 10S" mix was weighted and putted in a weighting bow (waiting for the additional KNO3 to be weigthed and mixed in just after)

- Then my sweet wife called for lunch. :-) and I did not wrote the weight down!

- After a loooong lunch break, back to the workbench, I poured directly my C+S in the rest of BP, screened it several times and wetted it

- Wondering: Wow, the dough is really smooth and nice: that charcoal and the KNP3 are really FINE, like lampblack... But KNO3, that fine? never seen...

- AND then OMG! did I mixed the KNO3 in? No! What was the weight of the C+S mix? not written down.

- Made a burn test after having dried a small crumble: no comment!

 

So even if I let it all to dry, there would be no chance to get the right missing KNO3 weight (only total weight could be measured)

 

In my view there is a good lesson from this:

- Mixing without writing down step-by-step what I'm doing is kinda dangerous. This hobby requires knowledge, precaution, but probably most of all self-discipline.

Edited March 7, 2017 by Sulphurstan

[lloyd]

"1 unknown term in excess in the equation :-("

-----------

Well, no, not NOW... but had you weighed it right after making the error, you could have discovered what the excess was, then used the spreadsheet to calculate the correct amounts of other materials to add...

 

<sorry>

Lloyd

[BlueComet24]

You don't need a spreadsheet of course, despite it making it easier. Figure out which chem you went over the mark by the highest percent (divide mass added by mass called for) and then calculate required masses for the other chems based on this mass (divide this chem's mass by its required percentage (75%, 15%, or 10%) and multiply it by another). Then subtract from this mass the amount of the chem you already added, and do this for the other chem.

[Lozzard]

Rocket tooling

[pyroman2498]

Eagerly waiting for my test information to be emailed to me so I can get my license.

Im also looking for some shows to do around my area!

[whitewolf_573]

In february i have been finishing my ball mill ,and today bought some firewood, white ash for lift and chestnut for effects. Tomorrow i will use my new tlud for first time.

[OldMarine]

I like those jars. What are they?

[starxplor]

Does that air intake provide enough input and how well does it spread inside the container?

[Sulphurstan]

Granulated some willow bp

[whitewolf_573]

I like those jars. What are they?

I have bought them in inoxia (inoxia.co.uk) , a uk pyro store. They are , i think made of hdpe. I have got the 6L one.

 

Does that air intake provide enough input and how well does it spread inside the container?

Is a 2" valve. You can open it from almost none to full. In a tlud , i have read is better to have it only a bit open, too much air is bad , too little either puts off the fire or it slows down the cooking,

 

Today i have used the tlud for first time, and i opened the valve at 1/4 or a bit less, and cooked the wood for a hour. in every moment, through the chimeney you could see a white /grey smoke. After 1h, still there was white / grey smoke, but i removed the chimeney, and put a slightly moisten rag, and a piece of wood and a bit of weight, to let it cool all the night.

 

Tomorow i will break it a bit, sieve, and mill. Then make the first batch of bp in years We will see if my european white ash is so good and if i have cooked it well.

 

I think the tlud works quite well, but we'll se once used more. The smoke thing is strange, i understood that a tlud generates almost no smoke, but in my case there is certainly some smoke,

 

The false bottom i think it does a good job, has many big holes spaced evenly in all the surface (bought with them drilled, i only drilled the lateral to have some more holes.

[lloyd]

Generally, a TLUD generates a FLAME from the exhaust, when the air is sufficient. It's 'touchy', at first, to get it right. Too much air will burn up your charcoal. But too little can cause it to be undercooked, for lack of the 'local zone' heat generated as the flame front burns down the column.

 

If this batch doesn't give good charcoal, consider opening the bottom vent a bit more, AND allowing some air in around the bottom of the 'stack', so that the components there can burn -- even if you have to light it!

 

Good luck!

 

Lloyd

[OldMarine]

I thought I had a picture of my TLUD burning somewhere but it must be on my tablet. You can just see the flame coming from the stack and glowing through the vents at the base of the stack. Absolutely no visible smoke.

[whitewolf_573]

What happens if the stack is too large, as mine is 1m ? (plus that flexible part for this occasion as instead of doing it outside i decided to put it a bit sheltered where i have the ball mill - not being used - as it looked like it was going to start raining in that moment)

 

The diammeter of the stack is roughtly 6", the base of the stack 7" and a 5 gal bucket - 35 cm diammeter.

Generally, a TLUD generates a FLAME from the exhaust, when the air is sufficient. It's 'touchy', at first, to get it right. Too much air will burn up your charcoal. But too little can cause it to be undercooked, for lack of the 'local zone' heat generated as the flame front burns down the column.

 

If this batch doesn't give good charcoal, consider opening the bottom vent a bit more, AND allowing some air in around the bottom of the 'stack', so that the components there can burn -- even if you have to light it!

 

Good luck!

 

Lloyd

 

Thanks Lloyd. I based my design in the tutorial of the tlud from fireworking, but changed the holes in the bottom for a 2" valve and a false bottom (i remember a post here in this forum where you put pics of yours explaining why was better using a valve and a false bottom)

 

 

So the number and size of the holes in the stack / chimney , is quite important to have a good combustion (to have negative presure or a good draw of the air from the intake valve into the wood and through the stack, I think mime are 6-8mm holes, about 8-10 , i will measure them and count the number.

 

When i removed the stack , there was still smoke, i stired the charcoal and it didn't burnt again, it was like hot coal (or remembered that to me) and while putting a slightly moistened rag, a piece of wood and some weight it still generated some smoke. So i think was slightly undercooked perhaps. I removed the stack a hour later (more or less) after lighting it with a blowtorch and two por three firestarters made of sawdust.

I thought I had a picture of my TLUD burning somewhere but it must be on my tablet. You can just see the flame coming from the stack and glowing through the vents at the base of the stack. Absolutely no visible smoke.

 

In my tlud i can remember seing a red glow through the holes at the base of the stack, but there was smoke also.

I will see how this first charcoal behaves for bp. The next batch will be better sure. As said LLoyd is matter of adjustment and learn how to use the tlud.

Edited March 11, 2017 by whitewolf_573