My salute was... ok

[yvanblo]

Hello everyone. I searched for an answer, but didn't find what I was looking for. Perhaps it won't be discussed here due to rules and regs... hope that's not the case. Anyway, I've been making fireworks for many years; fountains, rockets, gerbs, wheels, aerials, etc. I didn't do flash for the first 10 years, just so I could better understand what I was doing before I started messing around with something that could easily remove fingers and destroy eardrums. I started small, obviously; 3g or so. Nice little m80 style crackers. I've slowly scaled up for several years, and this year made a 60g 70:30 salute (german dark AL). Though it did some damage, and made an ok noise, I expected much more. We were 50 feet away, could barley feel it, and the sound didn't hurt my ears.

 

I'm wondering if my construction technique is wrong (too much flash in the tube? Not enough containment? wrong ratio? wrong flash?) I feel like once I got over 20g, the noise didn't increase as much as I would hope. If this is an ok place to discuss, let me know, give me some advice, and I'll give a quick explanation of how I made it. If not, I'll zip my lips and delete the post.

 

Thanks!

[GreginCA]

Straight off, constructing a ground salute with 60 grams of flash and standing 50 feet away is not a particularly bright idea (no pun intended).

 

A properly constructed ground salute containing between 15 to 20 grams of 70/30 flash will impart a serious blast wave from 50 feet even if you only contain it in a Dixie Cup. 60 grams in a Dixie Cup will light up every car alarm on a typical city block. Perhaps you aren't mixing the aluminum and perchlorate adequately would be my initial guess.

Now the lecture: Flash is a beast...... If you are compounding 60 gram batches you have nothing to lose by kicking it up to 100 grams, putting it into a 3" aerial salute can, connecting some time fuse, adding some lift and lofting it 300 feet into the air. Much safer than large ground salutes in my humble opinion. If your flash is slower, confinement becomes the key. More isn't always better. Take the time to read Pyrotechnica IX & XI, all The Best of AFN series, Pyrotechnics by "Alexander Hardt", etc.

 

PS: A good bottom shot beats the hell out of any ground salute :-)

[myfriendtheenemy]

I used to make really fast flash 10 grams at a time by finely screening it together a few times. After hearing some stories about how dangerous that is, I now only make five grams by screening the ingredients separately and diapering them together. With this technique, I found that the flash is a little bit slower because I'm not intimately mixing them. Maybe that's your problem.

[yvanblo]

To clarify where I set this off, and how far away we were... We live in the country with 40 acres of untouched woods behind our house. We walked back in the woods a 1/4 mile or so, and there were lots of large trees between us and the salute. Was probably closer to 75 feet away. I said 50 because it was so underwhelming.

 

I mixed in the usual fashion; diaper method. It looked smooth and consistent and I screened the perc and AL onto the paper.

 

One day I'll lob one into the air, but I don't have the best luck when it come to mortar timing, and I'm just too nervous that it will come back down before going off.

 

I'll look up the references you gave and do some more reading. Thanks for the constructive criticism.

[yvanblo]

...

PS: A good bottom shot beats the hell out of any ground salute :-)

 

I forgot to ask how a bottom shot works. Sounds safer and cooler than a flash cracker. I've done a few internet searches for how to make a bottom shot, but there isn't all that much information that is readily available.

 

My main fireworks creations tend to center around fountains and such because they are beautiful and easy to know where to watch. And big wheels. This years wheel is just under 10 feet across. I put 12 drivers and 3 fairy fountains on it this year.

 

I still love to make loud booms... and they don't always have to make craters. I have a 3/4 ID cannon that makes a good noise. I'd love to hear more about bottom shots. I've heard of them, but not in detail as to what they are and how they are made.

[Arthur]

A ground salute loses energy into frothing up soil and vegetation. There is usually some form of crater which is powder used to neither audible or visual effect, and possibly pebbles turned into bullets. A salute is best raised off the ground a little (inches), or sent well into the air -if your shell timing is really good.

[pyrokid]

In principle a bottom shot is the large salute which makes up the final break of a multi-break cylinder shell. Construction methods vary. The bottom shot serves a structural purpose in the shell: it acts as a solid base which is acted upon by the lift charge to propel the shell from the mortar.

 

One account I read describes the construction of the bottom shot casing from pasted, folded, and rolled newsprint. I would expect that contemporary builders use a heavy paper core and pre-fab end disks. In either case, the flash should be well-served into the casing.The fulcanelli papers have more technical detail.

[Richtee]

In principle a bottom shot is the large salute which makes up the final break of a multi-break cylinder shell. Construction methods vary. The bottom shot serves a structural purpose in the shell: it acts as a solid base which is acted upon by the lift charge to propel the shell from the mortar.

 

 

Hmmm... seems to me a “bottom shot” would be placed at the TOP of a multi-break. And if so- it’s not a structural component. I’m gonna build one. Never have.

Edited July 6, 2023 by Richtee

[Mumbles]

Pyrokid summed it up really well.

 

Rich, most pseudo-traditional shells have the main delay fuse on the top of the shell so the bottomshot being the last to go off is going to be on the bottom of the shell in the mortar. The area where the time fuse or spolette enters a cylinder shell is often one of the weakest points of the shell construction. It lends some insurance against flower pots, or at least provides peace of mind, by having the spolette or time fuse on the top of the shell. For basically anything bigger than a commercial class C sized shell I'd top fuse them.

 

There's 3 primary methods I've seen to make bottom shots. One uses rolled up newspaper strips (called books), another uses thick hardwall machine wound casings, and the final is to have a smaller salute inserted into a larger casing and the void filled with a non-compressible filler like sand. The last one is popular in Maltese techniques. They're all basically different flavors of a thick walled casing typically filled with flash. There's more to it than that, but I'd be writing a novel trying to describe the ins and outs of it. I've tried all 3, and there are positive and negative attributes about them all.

[Richtee]

Pyrokid summed it up really well.

 

Rich, most pseudo-traditional shells have the main delay fuse on the top of the shell so the bottomshot being the last to go off is going to be on the bottom of the shell in the mortar. The area where the time fuse or spolette enters a cylinder shell is often one of the weakest points of the shell construction.

Ahhh...OK I see. As I do not fuse that way...my bottoms would be at the top But then again.. when yer only doing 1.75 shells any more... Yeah, you gotta build the sheet out the bottom regardless. That’s some force to contend with.

 

Thanks Mumb.