Comets

[psyco_1322]

I think im going to make a TT comet and attach a willow rising tail to it. Wacha thinks?

[Mumbles]

Psyco, not to be detrimental, but I don't think that would add anything to the effect. They will likely be indistinguishable. They are essentially the same effect. If you want a longer hangtime from the TT, try adding some coarse charcoal or lampblack.

[psyco_1322]

lol And someone took me seriously. I was just joking around with that post to see if anyone would pay much attention to it. Yah that wouldnt really work all to well in the terms of effect enhancing.

[mormanman]

Well on the topic of hang times for TT you could use Bamboo charcoal BP with its slow burning character but adding more coarse charcoal would be easiest. I use newspaper for TT most of the time unless I have Pine.

[Zmuro]

3in Comet C6 + 10% Ti Sponge: http://www.youtube.com/watch?v=K4sonA49XME

[FrankRizzo]

lol And someone took me seriously.  I was just joking around with that post to see if anyone would pay much attention to it.  Yah that wouldnt really work all to well in the terms of effect enhancing.

Completely OT here, but you're an only child, right?

[qwezxc12]

3in Comet C6 + 8% Ti Sponge: http://www.youtube.com/watch?v=K4sonA49XME

Really nice. Was it cored or solid?

[Zmuro]

3in Comet C6 + 10% Ti Sponge: http://www.youtube.com/watch?v=K4sonA49XME

Really nice. Was it cored or solid?

It was solid

[psyco_1322]

lol And someone took me seriously.  I was just joking around with that post to see if anyone would pay much attention to it.  Yah that wouldnt really work all to well in the terms of effect enhancing.

Completely OT here, but you're an only child, right?

I take that as Off Topic (OT). Yes, kinda, but....

 

No I have a young brother but he doesnt want much to do with my "stupid fireworks crap". Somedays he does, somedays he absolutely doesnt, smoke bombs he likes to make, shells is a hole nother animal. I wish I was a only child. More peace, less disturbance.

[Mumbles]

I don't believe the comment was in any way related toward fireworks or having someone to work with.

[oskarchem]

Ok, so this is my First comet the comet and the lift were not hermetic so some of the lift gases went around and meking the comet go to low and fall on the ground...Burning a hole in the grass (you will be able to hear my dad shouting: "The grass" in the vid)

 

Mg Comet

[hst45]

oskar, nice job. It had a nice sizzling sound to it. The low shot is too bad, but as you know a tighter fit or more lift will cure this fine. If your comet is too loose a fit in the tube you can just wrap a few turns of masking tape around the top of the comet. The tape will burn away after it has launched and will cause no problem except for the potential fire issue. Which, by the way, is another reason why I love winter so much. No fire problems!

[oskarchem]

Thanks. Yep I love winter aswell it's the best for pyro, no worries.

I have made one for this eavning, (just hope it will dry before 9pm). But I find that masking tape has a problem sticking to pyrotechnic devices( I'm talking about the comet (the actual charge)).

 

PS: I just love the sound of a shell/comet coming out of the mortar

[hst45]

I find that masking tape has a problem sticking to pyrotechnic devices( I'm talking about the comet (the actual charge)).

 

PS: I just love the sound of a shell/comet coming out of the mortar

Then try a few turns of thick twine such as jute or sisal, and throw a dab of glue on it to hold it in place while it fires.. This should "tighten" the comet/bore ratio too.

 

Yeah, the "ffWHUUMP!" sound is great!

[qwezxc12]

No suggestions there, those looked great. Fire those from the top of the Tower of London and people will think you're "V" for Vendetta

Love the sound of the lift! To be honest, IMO that's half the pleasure of lighting shells...the rip of the lift in the mortar.

[psyco_1322]

Yah as long as that rips loud enough:) If not you get to duck for cover, but that jsut makes the second boom even closer thus making it better

[cplmac]

Squib those looked real good, I'm really surprised how fast they burned being 2" long.

Oskar I've had sizzling Mg before. I pressed a BP rocket with a Mg turnings delay and it sizzled like crazy for about two seconds before it blew up. Never did figure out what caused that but the sound is unique.

[oskarchem]

Yeah, it doesn't fo that sound with anything else... Maybe it is because of thez high burning temp of the Mg ribbon... If anyone knows tha awnser please tell

[TheSidewinder]

Squib, just as a caution!!

 

You do NOT want to make the shells fit "tightly" for more thump. That's risking a mortar blowout. If there is the least little debris, or the mortar gets the least bit deformed from shooting, that tight fit will contain it long enough to blow up the shell and the mortar.

 

ALWAYS make your shells of a size that they drop fully into the mortar by gravity ALONE. Wiggling the shell just a TINY bit to get it to drop in is ok. But once it starts in, it has to drop fully on its own. If it sticks, the shell is too tight and you run the risk that I mentioned above.

 

Stay safe, we want to see more of your shells.

 

M

[MileHighPyro]

qwezxc12,

 

Just read the beginning of this thread, and am quite interested in the colored comets. You mentioned that you got the formulas from rec.pyro, and I would normally try searching there first, but with all of the sporge lately, I think it would be an exercise in futility. Would you mind sharing the colored comp formulas that you used?

 

Also, I recently went to my local Home Depot to pick up some Elmers Resorcinol glue for another project, but they no longer carry it. I also tried a few wood shops, and I can't find it anywhere locally. Seems the only way to get it is to order it. Would be interested to know if you have been able to get it from any of the national retailers.

 

On the topic of large comets, I make a 4" x 5" tall, cored charcoal comet for a rising effect on a 6" shell. I cut off part of a 6" plastic shell (the diameter of this "dome" just fits inside the 4" comet press) and filled it with Bondo. I drilled a hole through it so that it slips over the spindle, such that I'm able to pump these large comets with a core through the whole thing, and a concave surface in the bottom that fits perfectly on a 6" shell. I dry the comet, paste it with 3 turns of 70 lb papper, and dry again. Finally, I use hot glue to fasten the comet to the shell, then add a few more strips of pasted paper down the comet and onto the shell, ending with 1 more wrap around the comet to keep the strips from pulling loose from the comet. I stuff a few strips of blackmatch down the core, launch it comet side up, and have never had one come off or fail to light. I add about 10% of some scrap 10-40 mesh Ti alloy chips to a modified dextrin/ Tiger Tail type comp with 1" burlap strands added for strength. With a 3/4"core, and 4" dia. burn surface, it really roars on the way up, and happens to burn out just before burst.

 

Any help with the colored comp formula would be greatly appreciated.

[Mumbles]

Here is the original formula.

 

Red comet, with tail: %

Potassium perchlorate - 43

Strontium carbonate - 14

Saran 506 --------------14

Magnalium 50/50, -200 mesh - 10.5

Red gum ----------------3.5

Charcoal ----------------7

*Titanium, sponge PLUS 30 mesh - 7

 

 

Additionally, here is the link to the original thread. It took me a wihile to find it. Not because of the sporge though interestingly enough. It doesn't seem to mess up the search results.

 

http://groups.google.com/group/rec.pyrotec...6b797c2c1c1edc5

[qwezxc12]

Thanks Mumbles for digging that up.

 

MileHigh,

 

I altered the formula a little, mostly because 1/2% are a bit silly if you are not using reagent grade chemicals. The end formula I used on the colored Ti comets is:

 

Potassium Perchlorate............43

*colorant*............................see below

Saran..................................14

Magnalium...........................10

Red gum..............................4

Charcoal...............................7

Titanium, sponge...................7

 

Bind with (additional):

Paraformaldehyde (catalyst)....1-2%

Resorcinol Resin....................8%

Methanol...............................4%

 

I've successfully used 15g Calcium Carbonate (orange), 15g Strontium Carbonate (red), 10g Cryolite and 5g NaNO3 (Yellow), and 9g Copper Oxide / 6g Strontium Nitrate (violet).

 

So far straight Barium Carbonate has yielded a pale, unsatisfactory green in the above percentages and adding Barium Nitrate makes it yellowish and too fast a burn without adding to the saturation. Both straight Copper Oxide and Copper Carbonate also make a poor blue.

 

I'm hoping to tweak blue and green using portions of Ammonium Perchlorate and varying colorants.

 

I have bought Weldwood brand resin at True Value / Ace, but I'm currently using Cascophen from Aircraft Spruce...it's 1/2 the price of Weldwood when buying a quart kit vs. two pint kits at the hardware store.

 

Hope that helps.

[Bonny]

Has anybody ever tried this comp?

 

White comet #1

Source: rec.pyrotechnics

Comments:

Preparation:

 

Potassium nitrate.................................96

Fine charcoal.....................................44

Sulfur............................................15

Dextrin...........................................10

 

I made a batch of 1" comets with +7 (-20 +40) Ti flakes (from Bob) for added effect. I don't think these will need any prime, but how about burnrate?If they are fast burning I guess I should wrap in kraft so only bottom ignites, otherwise fire as is?

I won't be able to test anytime soon though...

[Mumbles]

I made a composition similar to that before. I'm not sure exactly what went wrong with them. They burned alright at first, but then they seemed to absorb a bunch of water. The burn rate for a 3/8" star went from about 1.5 seconds to over 6! They had already been packed in a 2" ring shell, and burned all the way to the ground(and roof) and then some.

 

I have no idea what happened. I used the chemicals I always did, and never had a problem before. Haven't had the same problem since, despite still having the same chemicals. Probably a one time contamination issue,

[Bonny]

I made a composition similar to that before. I'm not sure exactly what went wrong with them. They burned alright at first, but then they seemed to absorb a bunch of water. The burn rate for a 3/8" star went from about 1.5 seconds to over 6! They had already been packed in a 2" ring shell, and burned all the way to the ground(and roof) and then some.

 

I have no idea what happened. I used the chemicals I always did, and never had a problem before. Haven't had the same problem since, despite still having the same chemicals. Probably a one time contamination issue,

I did also make some stars with the comp (no Ti). hopefull they don't absorb any water...especially the comets. I'll fire them over water just in case. Maybe I'l also only use the stars in 1" cylinder shells that I don't paste, only string and then some tape.