Water cakes

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sambo
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Water cakes

Post by sambo »

Anyone ever seen this before ? check out esp the last 2

https://www.youtube.com/watch?v=4FtRq4y9bt4
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richardh08
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Re: Water cakes

Post by richardh08 »

I've seen them used at St Albans, where there is a lake between the firing site and the audience. They are, indeed, very effective.
Even when I'm wrong, I'm convincing.
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biffo
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Re: Water cakes

Post by biffo »

I've never seen anything like those ,fascinating! B
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Lloyd
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Re: Water cakes

Post by Lloyd »

In the States, those are called "Frogs".

I first saw them at the 1996 PGI meeting in Muskegon, Mi.

Later, at Santore & Sons, we made them for two years straight for the nightly shows at Sea World, Orlando.

They are an astonishing effect to the audience, even though the concept is simple.

Somewhere, I even have a ShowSim simulation of that show.

LLoyd
"Pyro for Fun and Profit for More Than Sixty Years"
dave321
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Re: Water cakes

Post by dave321 »

interesting effect,

care to share construction details ? looks like a buoyancy aid in tubes with delay + flare type effects
sambo
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Re: Water cakes

Post by sambo »

Interesting, yes would be fascinated to have a clue as to construction ?
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Lloyd
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Re: Water cakes

Post by Lloyd »

They're quite easy to build. The only things that require careful tuning are the balance of the tube and the lift amount.

Most frogs have a pasted-in float built near the top of the tube -- it's often a piece of styrofoam that's been holed to snugly accept the tube. The tube is glued into the foam block, then a couple of layers of pasted kraft added to secure it well against lift and impact forces, and to waterproof the glue joint for a short while.

The tube sometimes requires a sand or clay weight in the bottom to counteract the bouyancy of the portion of the tube below water, as the charge burns down. That part of the tube begins weighted with comp, then becomes empty, and thus bouyant. If a counterweight is not used, the tube can tip over after the burn has continued for a time.

They are most-often inserted in the guns bottom-side down, with a piece of quickmatch up the side that will take the lift fire, and commute it to a time fuse on top. The time fuse must be also waterproofed, or of the waterproof variety, so when it hits the water at an arbitrary angle, it is not extinguished. The delay should be adequate to allow the tube to right itself in the water and become (relatively) stable before the effect begins.

Finally, although the effects are often gerbs or strobes, they can be most anything (including candle effects and even shell launchers, so long as the recoil or rocket force is low enough so as not to sink the tube while it's functioning.

Reprise: size the float to take the entire weight of the loaded tube AND any recoil or jetting forces. Include in that any counterweight necessary to prevent falling-over as the tube consumes it's load below water level. Match with quickmatch up the side, and waterproof time fuse on top.

LLoyd
"Pyro for Fun and Profit for More Than Sixty Years"
sambo
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Re: Water cakes

Post by sambo »

Thanks Lloyd, I really enjoyed reading that !

I would love to give this a go, I just need a big pond! I have a lot of sea where I live, not many lakes, wave proof might be pushing it lol ;-)
delboy
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Re: Water cakes

Post by delboy »

very impressive!
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richardh08
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Re: Water cakes

Post by richardh08 »

These effects aren't particularly new. I have a description by Ruggieri, writing in 1821, that is very similar to Lloyd's explanation (except he didn't have access to styrofoam).
Even when I'm wrong, I'm convincing.
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Lloyd
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Re: Water cakes

Post by Lloyd »

Richard is quite correct. "Water lanterns", "water lilies", and "frogs" have been around for nearly as long as display fireworks have been.

In 1996, I'd been making fireworks for 30+ years, but knew very little of the literature available. It was becoming associated with rec.pyrotechnics, the FPAG, and PGI that alerted me to the wealth of information available. That description by Ruggieri very nearly describes the modern incarnation of a frog.

If you're quite careful about tuning the lift and launch angle with inert (properly-weighted) samples first, one need not have a large body of water to try them. Our pond at Santore was barely 10 meters wide by about 15-18 long, and we tested them routinely there. I would think even along a sea coast there might be small bays or estuaries without significant wave action. (???) The depth of the water need not be more than about twice the length of the tube.

Lloyd
"Pyro for Fun and Profit for More Than Sixty Years"
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