33 replies to this topic

[maxman]

Rather than a delay mix, has anyone tried making a candle with a length of visco running down the entire length of the tube? This is how a bought one was made when I checked it out. Sawdust was used as the delay.

Now my question. When candles are made in this way say in a 1/2" id tube a 1/2" rammer can not be used, can it? the rammer would then not fit freely in the tube. It might sound obvious but is it best to use a smaller dia rammer? or cut out a section of the rammer? or possibly use a square section rammer? How are candles made this way professionally?

I prefer to do it this way as it seems that the sawdust delay acts as a wadding to give a better shot and always ignites the star

[sizzle]

If you use visco running down the sides you have to have some kind of block to stop the fire going all the way down the tube prematurely, I tried using visco as the delay and using carboard spacers to seperate the stars/lift, Result = crater in the garden. I supposed it could be done with a better spacer, sawdust as you said may be a good idea.

[pyromaniac303]

In some multi shot/cake type devices I bought, although they were only one shot per tube, they rammed a large amount of sawdust (about 3x the ID of the tubes) on top of the stars. They seemed to reach quite a height, even though the stars were about 1/4 to 1/3rd the size of the tube. Another unusual thing was that although each tube was around 1cm, there must have been around 0.2g or less BP

I found this out as I had some misfires when I examined them the following morning. So it seems like the extra pressure buildup caused by the sawdust allows you to use smaller stars, and less BP. I'm sure a 1/16th visco fuse running down the side isnt going to affect this too much, but if you are worried about it then use a small drill bit to drill down the side of your rammer, so you get a groove for the fuse to fit into.

[maxman]

That's exactly what I found.Sawdust used in the particular candle was about a teaspoon full and hardly any lift powder at all. If you use a delay mix then there is nothing on top of the star to confine the lift charge. I suppose you would need more lift then for the same job and that means less shots per length of tube.
I might try a square section rammer which would leave a gap for the fuse down the side, after all i'll only be ramming sawdust.

[pyromaniac303]

Just spent a few minutes cutting a chunk out of a 1/4" rammer, which I will test with the sawdust method when I get a shed built (any time around spring). Although not too experienced with multi shot candles, and usually fuse single shot ones into a 'cake' arrangement, I'll see how it goes and post some results.

Also I'm sure I heard somewhere that a mixture of wax and sawdust can be used in place of clay as a plug for tubes, anyone know much about this?

[Mortartube]

Most 14mm Chinese candles use granular clay between the stars (just like unground cat litter), that is drifted in so it is fairly compact. A length of Chinese visco runs the entire length of the tube. The lift is often a quite coarse granular BP. They are made with a round drift that has a channel cut down the side to allow for the fuse.

[concept]

Hey everyone this is my first post . I have got a diagram of how to make a basic roman candle saved on my computer but i dont know how to post it. If anyone wants a copy of it just PM me and ill e-mail it to you.

Edited by concept, 09 December 2007 - 09:08 PM.

[cooperman435]

Hi and welcome.

Whilst your offer is very nice, please take some friendly advice and read through the posting etiquet thread before proceding with more posts.

There is already a number of threads on roman candle construction and tecniques which this would have been better put in and you will see that there are also a number of diagrams posted too.

Please dont think Im being harsh but I really suggest reading then reading some more THEN posting as you will find nearly all the answers here already and you wont come across as someone who cant be bothered with the basics first.

Hope to see you on the forum more

Phill

[Neway]

But when the delay composition is rammed, there is a star under it. Is not dangerous if the star is made of sensitive composition such as a perchlorate one?

[Arthur Brown]

Every comp is dangerous to some degree. When designing a device you have to look at the effect you want and how to achieve that without unwanted chemical incompatibilities. -one reason why chlorates are less popular as they contraindicate sulphur hence BP

[Neway]

Yes, chlorates are incompatibles with sulfur, so I will never put them togheter, but my guess is another: can a standard perchlorate star (such as a veline one) ignite because I'm ramming on it some delay powder?

[Mortartube]

When I visited Standard fireworks many years ago, I saw the girls making roman candles (about 22mm bore) and they would make them upside down.

They would put in the delay and ram it, then tear off a piece of blue touchpaper from a sheet and ram that in. Then they would put in the star and a scoop of lift, then if I recall a bit more touchpaper before the next delay increment was rammed. So basically the touchpaper forms a barrier between the star and the delay. I never asked about this but I assume that it was to keep chlorate stars and sulphur containing delay apart.

[maxman]

I dint think chlorate sulphur comps were allowed in this country even then? Wasn't there something in the 1875 act that banned them?

[Mortartube]

You are not allowed to incorporate sulphur and chlorates in the same mixture, for instance a star mix, but it would not prohobit the use of chlorate stars in a BP burst shell. It is an "admixture" that is banned. Of course if you did use chlorate stars and BP in a shell, it would be wise to do all you can to avoid them coming into contact with each other.

Similarly, a chlorate based star could be used in a Roman candle with BP lift as it is not an admixture. Whether it is wise is another matter.

[karlfoxman]

Im thinking of revisiting large bore roman candles, but I have a question. I will be using the stuff I got from Plasticos Gamon, the delays are made from a cup shaped plastic wad. The 10mm Martin & Martins fuse goes through the middle inside a pre moulded tube. Question is do I need felt wadding to fit inside this cup? Anyone seen bits of spent Spanish roman candles on the floor after a show in Valencia? Im pretty sure I do not need the felt as these cups are a very good gas tight fit as they are. Im planning on making some nice 40mm Glitter w/blue tipped comet candles. I have all the tubes and parts to make them but just checking before I assemble one or two.