Plastic Shells for Lampares

[Wiley]

After reading Mumbles’ post on lampare pistils, I got to thinking. Why not use plastic shell hemispheres (or canisters, since some of the small sizes come in this shape) to make simplified lampare shells? They are already designed to withstand the forces exerted by a lift charge, so with a fuel-proof burst charge of whistle mix (perhaps with some Ti in it) sealed inside the shell, and the shell hemis sealed shut with something like Seal-All, they ought to make a nice little fireball. Perhaps one could rough up the plastic surface and paste them in for a better fit in the mortar, greater lift resilience, and a stronger break. Do you know the kind of plastic that these shells are made out of? Is this plastic resistant to oil, gasoline, and diesel? This just might be a fun project.

 

 

Now for the question about screens. The large particles in 2FA are 0.188” wide. I find the screens from Skylighter to be too expensive, and furthermore, I need a larger screen to make grating a putty ball of BP easier. McMaster sells a screen with openings that are 0.218” wide. Is this too far off to use for the manufacture and sorting of 2FA sized particles?

 

 

Soooo, red gum. In Nski’s tutorial on red gum BP, he adds only 1% of it to the mixed BP components, wets the dust with alcohol until a putty ball is achieved, and grates it through a 4 mesh screen. He then notes that these granules are quite weak when dry. Note that I am referring to his “simply screened” method; no ball mill required. Will adding 2% or so of red gum to this formula adversely affect the performance of this BP? Would it even make the granules stronger?

 

 

[dagabu]

After reading Mumbles' post on lampare pistils, I got to thinking. Why not use plastic shell hemispheres (or canisters, since some of the small sizes come in this shape) to make simplified lampare shells? They are already designed to withstand the forces exerted by a lift charge, so with a fuel-proof burst charge of whistle mix (perhaps with some Ti in it) sealed inside the shell, and the shell hemis sealed shut with something like Seal-All, they ought to make a nice little fireball. Perhaps one could rough up the plastic surface and paste them in for a better fit in the mortar, greater lift resilience, and a stronger break. Do you know the kind of plastic that these shells are made out of? Is this plastic resistant to oil, gasoline, and diesel? This just might be a fun project.

 

The plastic casings I have are made from polystyrene and will melt over time in contact with gasoline. A buddy of mine is working on some lampare shells right now and he has found that gasoline is really good at migrating out of whatever container you can find for it. Not only that but hot seal machines can light off the gasoline causing a fire.

Flash is what you want to break a lampare with, in order to get the fine mist and droplet dispersion you want has to be done with confinement so yes, you will need to paste the shell in as well.

Good luck and if you get it to work out, let us know and show us some video

-dag

[Wiley]

I am also curious as to the possiblity of using whistle in place of flash for traditional lampares. I wrote this a while ago; I think it asks the whole question quite well: "Ever since I first heard about lampares, I have always loved the concept of an aerial fireball, probably because I love ground based fireballs so much . Over the years, I have scoured the internet for any and all information I could find on these devices, and, thanks to this research, I now know the basics of lampare construction techniques.

 

 

99% of the info I have found on lampares indicates that flash is the burst charge of choice. This is an obvious conclusion to make, since flash is so good at completely vaporizing whatever is near it. Furthermore, the flash charge is almost invariably placed on top of the exposed cap end of the fuel-containing plastic bottle, presumably because this is the easiest end of the bottle to crush. I have also seen photos of a smaller flash charge being confined in a plastic tube and glued into the cap of the bottle so that the charge extends into the bottle itself when the cap is screwed on. Flash is not a composition for a beginner, especially when strapped to a bottle of liquid fuel.

 

 

What I would like to know is if whistle mix could be substituted instead of flash, that is, placing a large charge of whistle on top of the cap end of the bottle, just like it is done with flash. I am mainly interested in hearing your opinions about the shattering power of whistle mix relative to flash, since this subject, I think, is not very well documented. I know that one of you (psycho?) uses chlorate whistle to burst his lampares.

 

 

Now, I realize that there are many combinations of ingredients for whistle mix, but I am thinking specifically of 70:30:1 potassium perchlorate, potassium benzoate, and red iron oxide, made according to Ned’s instructions: http://www.skylighter.com/fireworks/how-to-make/whistle-mix.asp."

 

Comments?

 

 

 

 

[dagabu]

the flash charge is almost invariably placed on top of the exposed cap end of the fuel-containing plastic bottle, presumably because this is the easiest end of the bottle to crush.

What I would like to know is if whistle mix could be substituted instead of flash, that is, placing a large charge of whistle on top of the cap end of the bottle, just like it is done with flash. I am mainly interested in hearing your opinions about the shattering power of whistle mix relative to flash, since this subject, I think, is not very well documented. I know that one of you (psycho?) uses chlorate whistle to burst his lampares.

 

If you are dead set on using whistle, use Salicylate Whistle since it burns faster. The whole point to using a faster burning burst and the reason why BP does not work well is the brisiance of the charge, essentially meaning the ability to shatter. I have seen bottles get turned inside-out even with fast flash breaking them so I would be very surprised if whistle would do the job well if at all. The only reason why the flash is placed on top is that this is where the point of the bottle is and the easiest way to protect it is to pack flash around it. If you were to use a larger container, you could fully encapsulate the bottle of fuel with flash causing full atomization and an impressive fire ball.

Ultimately, the best thing would be to do as you had spoken of earlier in being able to put the flash in the middle of the fuel. The biggest problem in using bags and a ball shell is hydraulic pressure. Think of a balloon, if you drop a water balloon, it will flatten and then burst horizontally. Now lets fill a balloon with sand or rocks and drop it.

The balloon will break and the contents will just slump in a heap.

A ball shell full of water or fuel MAY break in the muzzle and never get out of the mortar. I would recommend smaller bags of a couple ounces each be placed in the ball shell around the burst charge.

-dag

[Wiley]

dag,

 

I always understood that the bottle had to be firmly supported to keep it from bursing upon being fired from a mortar. Additionally, I had thought that packing sensitive flash around a flexible plastic bottle would be a bad idea.

[Mumbles]

Whistle can be made to work just fine, at least with "normal" lampares. Since you're going for power, you may want to go with a catalyst such as copper oxychloride. As far as the lampare pistil goes, they are generally filled as close to being shot as possible. They will eventually start leaking both out of the shell, and into the fuse and rest of the break.

 

For mesh, the largest size doesn't matter a whole lot. Most of us use 4 mesh hardware cloth from the hardware store. It looks like it runs around $15 for a 3' x 5' roll. Stainless steel from McMaster or some other industrial supplier might last a little longer, but you pay for quality there. The stuff makes a good liner for drying trays too.

[Wiley]

So, Mumbles, by "normal" lampares, do you mean ones like this: http://www.creagan.net/fireworks/lampare.html? Approximatly how much whistle would be used for a 3" or 4" shell? Would a 70:30:1 mix of potassium perchlorate, potassium benzoate, and copper oxychloride work well? Just to get this straight, I would also like to know how "whistle fuel" (normally used for rocket motors and contains some sort of desensitizing oil) and "whistle mix" (components just diapered together) compare in their shattering abilities. Thanks for the info on the screen, I'll look for some of that at my local hardware store. Oh, and I found who it was that used chlorate whistle (nasty stuff ); his name here is psyco_1322. I'd appreciate it greatly if he could chime in here. Thanks for everything!

[Mumbles]

Yes, that is the sort of device I was talking about. Lampare made in tubes and plastic bottles. They will store practically indefinitely. If you go that route, some people recommend using RV fuel line silicone to seal the lid.

 

Besides the instructions on Danny's page, there are also instructions on Passfire, and in the PGI anthology I believe. Danny's is a little more conservative in the amount of flash used at 100g. The one on passfire, which I tend to follow more closely uses 180g of flash for a 4" lampare. I've made a few 5" versions in my day, and I think we were using at least 350-400g of flash on those. For whistle in the 4" size I'd start with around 100-150g of whistle. For a 3", maybe 60g. It's hard to say for certain.

 

I've never used whistle fuel which has any added lubricants or pheglmatizers in it as a burst, so I can't really speak to that. Powdered whistle mix still packs quite a punch even in comparison with flash.

[dagabu]

Besides the instructions on Danny's page, there are also instructions on Passfire, and in the PGI anthology I believe. Danny's is a little more conservative in the amount of flash used at 100g. The one on passfire, which I tend to follow more closely uses 180g of flash for a 4" lampare. I've made a few 5" versions in my day, and I think we were using at least 350-400g of flash on those. For whistle in the 4" size I'd start with around 100-150g of whistle. For a 3", maybe 60g. It's hard to say for certain.

 

180g to 400g of flash to break a lampare but only 60g to 150g of whistle?

 

What ever you decide, there are many ways to skin the proverbial cat and you should first decide what effect you are looking for. 400g of flash is a heavy salute while a much smaller charge can be used to completely shatter the bottle and get a nice fireball if you wish to go that route.

 

-dag

[Mumbles]

Different sizes Dag. 5" - 400g of flash, 4" - 100-180g of flash. I just picked somewhere in the middle to start with whistle. I just guesstimated the 3" charge. Whistle broke lampares do have certain advantages.

[dagabu]

Whistle broke lampares do have certain advantages.

 

OK, I'm listening... I would like to catalog some of the ways it is done other then the Passfire method.

 

-dag

[Wiley]

Yes, what kind of advantages? As dag said, I'm listening . Edited April 13, 2012 by Wiley

[Wiley]

Mum, could you tell us what kind of advantages there are to using whistle instead of vitamin F in lampares?

[WonderBoy]

An advantage I can think of would be the low light output. This would be useful if you were making a colored lampare, because the colored fuels burn fairly dimly. If you were to use KBenz (not sodium based whistle, as the sodium will wash out the color) whistle as a burst charge instead of flash, you would see the color much better.

 

 

WB

[Mumbles]

Way to give away all my secrets WB. I actually just missed this the first time around. He's right. Whistle, using potassium benzoate specifically, is very useful for colored lampares. They don't slam quite as hard, but the color is much more true. They can also avoid retina bleaching if firing a volley of even normal fueled lampares. The only way to really tell the difference is to fire a few of each type to tell for yourself.

[dagabu]

Good to know guys, I have not seen any colored ones yet.

 

-dag

[Wiley]

Thanks, that's good to know! However, the biggest issue there seems to be with constructing a successful lampare is finding a tube and a bottle which are compatible. This seems to be much harder do do for a 3" than a 4." I have a ready supply of Kirkland 500mL water bottles which can be stuffed into a 2.5" ID tube. Would one of these spiral wound mortar tubes be too thick for the shell to fit into the mortar: http://www.skylighter.com/mall/product-details.asp?id=670? Would these particular tubes be strong enough to survive being fired from a mortar? What have you folks used for your 3" lampares?

[Mumbles]

I agree that 3" is kind of an awkward size. For 3" salutes in general I tend to use these, sometimes cut in half. http://www.pyrodirect.com/ecom-prodshow/065-0007.html I also got several 2.5" OD tubes from friends who work in warehouses. Some of the industrial rolls of plastic wrap or aluminum foil come on rolls that size. Some of the others come on rolls that are 3.5" OD, so either will work for one application of the other. For bottles, I was using 8oz or so small round milk containers. Some lids are more stout than others, and I think I lucked out. I also put the lid side down, so that the flash breaks from the bottom of the bottle. This would also allow me to tell if it was leaking at all without ruining the flash itself.

 

The tubes you posted would probably work alright, though they may require custom made disks to cap the ends.

[Wiley]

Mumbles, after fiddling around with some measurements, I found that using a 2.5" mortar tube for the casing, assuming that spiking will increase the diameter by .125," and figuring that 4 wraps of 50# paper will add about .05" to the total diameter, the finished shell diameter is 2.93." If using a piece of sch40 steel pipe for a mortar (ID of 3.068"), there will be .143" of clearance. That seems a little tight, but it should work, assuming that the casing is strong enough . Also, Danny Creagan spikes all of his 4" lampares vertically only. How many other folks do this?

 

Skylighter also sells matching end disks for these mortar tubes .

 

Edit: After doing further research, it seems that using 2" Skylighter mortar tubes (convolute wound) with 1/4" thick walls in conjunction with an 8oz "Cosmo" (http://www.ebottles.com/showbottles.asp?bottle=2&kw=COSMO+ROUND+PLASTIC+BOTTLES-+HDPE) HDPE bottle would be a better choice. That way, the shell could recieve generous spiking and pasting, and still fit in a standard 3" mortar. The shell would be extremely strong and make the whistle burst charge more effective.

Edited April 17, 2012 by Wiley

[FrankRizzo]

Good to know guys, I have not seen any colored ones yet.

 

-dag

 

I think you've seen a few green ones at the last few PGI conventions. Psyco_1322 usually makes boric acid / methanol lampares for rocket headers.

[dagabu]

I think you've seen a few green ones at the last few PGI conventions. Psyco_1322 usually makes boric acid / methanol lampares for rocket headers.

 

Good to know, I really have to slow down when I am at Convention. It sure as heck wont be this year, I gots the superstring to figure out first

 

-dag

[Mumbles]

Wiley, I still mildly horizontally spike my lampares. It's hard to describe how without actually showing you. If you're on passfire, you can sort of see something similar there. I make a horizontal layer every couple of inches. When using a hard case salute, the spiking primarily holds the end caps on. Horizontal spiking doesn't really add anything besides making me feel better. For me it's a matter of stabilizing the verticals where I want them, and just finishing them the same way I'd finish any other cylindrical shell.

 

I think the construction method you describe will work just fine. You want around 5% gap, so you're just about perfect The sort of seat of your pants approximation is 3 * mortar ID for the final circumference of the shell. This will give about 5% gap. Circumference is pi * diameter. Multiplying pi by 0.95 is almost 3. You wont know until you try it though. Remember you still have quickmatch and lift wraps if desired.

 

Now that I've come to my senses and realize that you'll have a larger tube ID that I'm used to working with you should be fine. A lot of things are about 2.5" OD. I used to use an old 12oz contact solution bottle as a former for 3" shells that would fit inside. Standard aluminum cans are 2.55" OD, so you can use one as a guide if needed. There probably exists some water or soft drink bottle the right diameter. For 4" and 5" lampares, gatorade bottles work great. They're strong and easily available, plus I drink a lot of gatorade at pyro events. It's almost as if it was designed for pyro. 20oz fits well in a 4" salute core, and 32oz fits well in a 5" salute core.

[Wiley]

I just took a trip to the local Kwik-e Mart with a 3" ID cardboard tube under my arm, and test-fitted pretty much every suitably proportioned plastic bottle in it. Nobody looked at me like I was crazy (amazing )! This little tour was necessary because I seldom, if at all, consume soft drinks. It looks like I might have to change that tendancy soon. I found that a standard 20oz Coke (or 7Up, Mt. Dew, etc) bottle fits in the tube with, oh, I'd say about .25" to .375" of slop. Mr. Creagan uses what certainly appear to be 20oz bottles of this type. A 1 liter bottle is far too large to fit in a 3" ID tube; if I recall correctly, the 1L bottle I have measures about 3.375" in diameter. BTW, Skylighter's 3" spiral-wound mortar tubes would make great 4" lampare cores. I've pretty much decided to "do" 4" lamps, because it's either difficult or expensive to find compatible components for 3 inchers. Mortar fit could possibly become an issue with larger ID cores, and smaller cores reduce fuel-carrying capacity (and I would have to order the bottles online, i.e. $20 shipping for a $2 bottle ). Components for a 4" are cheap and easy to come by, not to mention the fact that even a 3.5" OD core gives ample room for generous spiking and pasting.

 

So now the question is about the rather sloppy fit of a 20oz bottle in a 3"ID tube. Mr. Creagan clearly has great success with this combination, but he doesn't detail what he does about the gap. It appears that he fills it with caulk, but I'm open to suggestions. Perhaps clay/fine sawdust packed around the bottle, or maybe an expanding foam?

[dagabu]

Look into recycling bins, we recycle a thousand 20 oz. bottles a week.

 

-dag

[Wiley]

I found this interesting photo on the web. The caption reads, "Preparing a unique 'Fire Flower' shell for launch at Newport Bonfire Display 2003." It looks like he is doing exactly what I originally proposed! From the look of the photo, it appears that the shell is being filled with fuel immediately before being fired.