20 replies to this topic

[Gazza]

I intend to construct an aerial fireball effect, known among the pyrotechnics community as a lampare.
I have decided to go one step further and add a small amount of boric acid to methanol fuel, to obtain a green fireball effect. The methaol reacts with the boric acid to form a borate ester, which is easily volatilised and burns with a green flame. However, I want to do this safely and without getting burnt! So, I would appreciate some advice from fellow pyros.
How is the lampare ignited? Does the fuel need to be atomised into a fine spray before ignition?

[BrightStar]

I intend to construct an aerial fireball effect, known among the pyrotechnics community as a lampare.
I have decided to go one step further and add a small amount of boric acid to methanol fuel, to obtain a green fireball effect. The methaol reacts with the boric acid to form a borate ester, which is easily volatilised and burns with a green flame. However, I want to do this safely and without getting burnt! So, I would appreciate some advice from fellow pyros.
How is the lampare ignited? Does the fuel need to be atomised into a fine spray before ignition?

The most common method seems to be to seal the fuel in a plastic bottle, supported inside a thick walled cardboard tube as a shell case and burst with a big flash charge at one end. From Passfire, a 4" lampare might contain 1 litre of fuel and a minimum 170g of flash.

This is, IMHO, ludicrously dangerous as it combines handling of volatile fuel (what if it leaked ) with a big flash salute. It's not something I would ever consider making myself, even on a smaller scale.

Nothing wrong with reading about it though

Edited by BrightStar, 28 April 2008 - 03:32 PM.

[pyrotrev]

The most common method seems to be to seal the fuel in a plastic bottle, supported inside a thick walled cardboard tube as a shell case and burst with a big flash charge at one end. From Passfire, a 4" lampare might contain 1 litre of fuel and a minimum 170g of flash.

This is, IMHO, ludicrously dangerous as it combines handling of volatile fuel (what if it leaked ) with a big flash salute. It's not something I would ever consider making myself, even on a smaller scale.

Nothing wrong with reading about it though

Another way that's been used is to well fuel-proof a normal spherical shell with some suitable varnish, then mount this inside a larger plastic outer shell case. The fuel is added into the space in between shortly before launching. There are obviously a lot of mechanical issues to be addressed but it can give the effect of a good peony/chrysanthemum shell with a fireball pistil - the photos I've seen from the FPAG were great.

[Arthur Brown]

The biggest lampare I saw was a 20 litre water cooler jar filled with diesel and launched from a mortar. Drastically over the top.

[cplmac]

A friend of mine made an 8" lampare with one gallon of gasoline in I think an apple juice container. It was initiated with a kilogram of flash powder. Honestly most lampare aside from the boom are pretty boring because the fireball is never that spectacular for whatever reason. I've seen dozens of lampare and maybe one or two had a significant fireball but they all had a significant concussion. The biggest problem with lampare that I've seen is getting all the fuel to burn. Atomizing it with a large flash charge is probably the best way to atomize it, but I've seen plenty lampare spray gasoline unburnt all over the place even though most of it did burn in the break. Here is a lind to the 8" my friend made,

8" lampare capping a couple short finale chains

Edited by cplmac, 28 April 2008 - 10:52 PM.

[Asteroid]

Why not use napthalene or lycopodium? maybe even coffee creamer? Surely this overcomes the problem of a volatile liquid fuel?

[Arthur Brown]

COPAE by Davis mentions Lampare as rocket headers. See if his method appeals to you, and your supplies.

[Gazza]

My objective is to produce a green fireball effect by reacting boric acid with an alcoholic fuel (methanol) to form a volatile (easily vaporised) borate ester which burns in air with a greenish flame. The chemistry dictates that I can not use conventional lampare fuels, like petroleum or diesel for the green fireball effect I am trying to produce.
Boric acid is popularly used among fire jugglers and fire spinners dissolved in methanol to give a deep green flame, so it might indeed be possible to create a green lampare effect from this chemical, using a flash formula to atomise the liquid into tiny droplets before ignition. Obviously, the flash formula and the liquid methanol-boric acid mixture will need to be held in separate compartments and never be allowed to mix!

[dr thrust]

COPAE by Davis mentions Lampare as rocket headers. See if his method appeals to you, and your supplies.

yes it does appeal! to me, heres a 1lber i'am working on at the moment, complete with 100ml fuel header which is contained inside a tried and tested mastic tube header with a small flash bag underneath

Edited by chris m, 29 April 2008 - 08:25 PM.

[Arthur Brown]

Consider the Kodak film pot! As salvageable from all mini labs. pierce the base add a delay and a small burst then fill with fuel, snap the lid on and launch it

[cplmac]

Why not use napthalene or lycopodium? maybe even coffee creamer? Surely this overcomes the problem of a volatile liquid fuel?

I don't know about lycopodium but napthalene and creamer don't work well at all in lampare. Napthalene doesn't even work very well in creamoras type hits, all it does is make everything within 50 meters stink like hell for a few weeks. I don't remember who built them but at the MPAG shoot last October a couple of the shooters brought out a dozen or so lampare rockets and they were excellent. In fact, I think that might be my next rocket header.

[dr thrust]

found this lampare video, looks like everbody there lapped it up just listen to the guys laugh at forty seconds lampare

[cplmac]

My all time favorite FIREworks scene was at a show I worked on at an airport in the area about three years ago. We did the fireworks show but another company set up a fireball scene for the jet powered truck that did a hot lap down the runway. The odd echoes you hear are the soundwaves rattling the hangar behind us.

WALL OF FIRE

[dr thrust]

wow a wall of fire indeed!, back to the first post heres a vid of the methanol,boric acid green flame green ! ohhhhh soooo pretty got to try this one

Edited by chris m, 04 May 2008 - 11:36 PM.

[cplmac]

That's a real nice green. Did you have to do anything special in the mixing? I've had a bit of trouble sometimes getting the strontium chloride to mix well with methanol.