Roman candles

[TheEskimo]

After my brief hiatus, I have been experimenting with roman candles. There are two methods that I know of: The "normal" way, and the Gary Smith method.

The normal way consists of plugging a tube, then droppping in lift, a star, a bit more lift, and compacting this slightly. Then a delay is added, and this is firmly rammed. This is then repeated until the tube is filled. This can be altered by using clay plugs and fuse as the delay. This can be seen at: http://www.fogoforum.us/romancan.php

The Gary Smith way is slightly different. It consists of cutting short sections of tubing, and assembling only one section of the candle: Lift, a star, and some compacted delay. This is then repeated until you have as many shots as you like. These individual shots are then glued and taped to gether to form one continuous candle. This can be seen at: http://blog.skylighter.com/fireworks/2009/...an-candles.html

I have been using the normal way. I use cylindrical D1 3/8 stars in a 1/2in tube. The stars are loose, but with not a lot of space. I use a 1/4 teaspoon of fine BP, and place in a star. I sprinkle on a bit more BP, and tamp this down lightly. I then place in about 1/3 tsp of C8+Ti as the delay. This is rammed dry. I then repeat. I have managed to get rather reliable candles. I will post a vid on Sunday night...I will be out of town all weekend.

Anyways, do you guys try candles? If so, what methods do you use, and how have the candles worked? Post some vids, pics, and discuss.

[Mumbles]

There is actually a third method that is better suited to larger roman candles, which are the kind I have experience with. Experience if you count the two I've made. The type that fire shells and large comets over single stars. They're made similarly to the method with the rammed delay. Instead of additional lift over the top, a fuse (10 sec/ft) is ran down the side of the tube. A disk, lift, comet/shell are dropped down, and instead of a delay a plug of sawdust is rammed in. There was something special about a passfire being used from the top to the bottom of the shell, but I don't remember the details.

 

I think you tried to mention this when describing the fuse and the clay. Ramming clay might make too solid of a plug, and cause the whole thing to blow up.

 

Well, there might be a fourth method, but it is more suited to bulk manufacture. Thick felt plugs are cut, and a piece of time fuse is put through the center. A friction fit is used, and apparently can be made to seal it off from fire.

[Twotails]

I tried a small candle, I did get it to work, its located in my youtube under Roman Candle test i think, I used small(Maby 5mm squares) of sparkler star(dident light well) It did show that it lifted the star out of the tube, and continued to fire, maby three four times. I used (bottom up) Fine KP, Star, little more KP, Then mill dust, packing this solid, and repeat. the tube was just big enought to squeeze the star in( dident have round or cylindrical stars so i had to make due) it was maby 9in in hight, with 1/2in clay plug on the bottom.

 

It worked to suite my needs for a test.

[firetech]

Mumbles the ones you've had experience with the ones that are a few feet tall and a few inches in diameter?

[Mumbles]

Yeah, 3 feet tall, 2" ID. I think they were 5 shots plus a mine on top. The guy who taught me has been making some serious ones lately. 5 feet tall or so, 8 shots or so of multibreak inserts. I forgot something before, these are plastic tubes. I do have some cardboard though. If you live near a mortar tube manufacturer, see if you can buy uncut class C tubes. That is what I used. You can remove the plug, and clean them out, and they are reusable. Cardboard will only last a few times before it becomes noticeably enlarged.

[firetech]

I really have no clue if I do. I doubt it. Thats a pretty nicely sized candle. How long does that take to prepare?

[Mumbles]

If you have the inserts/comets already made, maybe 10 minutes. It's pretty quick.

[firetech]

How does that fuse stay put when you're putting all that stuff down there?

[Mumbles]

You bend the bottom into a hook, and pinch it down with a disk at the bottom. Or you can anchor it to the plug at the bottom. If I were to do it my own way, I'd tape it to a disk at the bottom and let the weight hold it down. The rammer for the saw dust has a small notch to avoid crushing the fuse. It was just a wooden plug with a notch attached to a metal rod. They are one of those things were it isn't too complicated, it is just easier to pick up the intricacies in person.

 

The loading order is

 

Disk

Lift (~10g I think) My notes say 1 1/2 tsp, but I seem to recall them being tablespoons

Insert

2x 1/2 cup of sawdust (rammed separately) - My mentor was a fan of 6 strikes per increment.

Disk

...Repeat

 

The fuse I think I said was 10s/ft visco. Mannitor, thermalite, and PIC work great too. I bet with good compression and some luck, blackmatch could be used. My mentor liked to put a mine on top, but I always thought it was weak in comparison with the shells(he never leaves enough room for good lift). I've been theorising about a nice fountain, but I am working on logistics.

[psyco_1322]

I tore apart a whole 5 shot 2" crossette candle. Well I pulled out its guts piece by piece, leaving the tube intact. I have about 6 of the tubes from a shoot I helped with. One candle didn't go off

 

There was no mine. The shots had felt discs over them. There were heavy paper discs with time fuse glued in and slurried on both side to pass fire. The crossettes were actually 1" that had thick paper tubes they set in. Everything fit rather snug in the tube. Thinking it was a Lidu candle, but maybe not.

 

I believe Passfire has a tutorial on the sawdust packed roman candles. I have made then one. two shots before just trying it.

Edited December 12, 2009 by psyco_1322

[Swede]

Reliable Candles are tough. I like the thought of using a fuse on the side, plus wood meal or sawdust to separate. Perhaps the technique could be adapted to an external fuse... a ssmall hole is drilled (carefully) into each lift charge, and primed with meal. The fuse is carefully laid on the exterior, in contact with the line of primed holes. Then, the candle is wrapped fairly heavily with Kraft. A good fuse would be a smaller one, say a 3/32" job.

 

The thought of making individual charges, then gluing them together, does not appeal to me. You may as well glue the charges to a board, chain them, and make a cake.

[firetech]

Swede's got a good point. Is there any real advantage to making a candle? It's definitely a cool idea and a good technique to know, but why not make a cake or chain shells together in a rack?

[Arthur]

The "Trad" way is to have three compounds, Star, lift, and candle comp which is SLOW!

insert lift, star then candle comp and ram, repeat til the tube is full!

The rammer candle comp will throw out a fountain of sparks as it is only a fountain comp anyway, the the fast comp will throw out the star.

 

To get the timing equal the candle timer comp is added and rammed equally each time. To get the heights the same each time the bottom lifts need to be much less than the top lifts as the short top lift does not use the lift efficiently.

 

I've actually watched Kimbolton Fireworks make big (2") candles using the time fuse in felt method, the stars were 50mmDIA and a bit longer and the timers were similar. Still they used two grades of powder one to passfire round the star then a lift, and again there were 8 different scoops for measuring the lift powder in the different measures for the length of barrel they would fire through.