1569 replies to this topic

[maxman]

Flipin' heck! I like it. Well my 3" shells are no where near that good! I really had high hopes moving up to whistle booster from just plain BP. I was scared as hell making and handling a few grams of it. So either it must be rubbish what I have made or just no where near as strong as flash. I read all the hype about whistle and how it is called organic flash and second only to flash. H3 being next lowest on the passfire list. I wont be using chlorate so wont be making any H3 to try.

I might try whistle at 76/23 next to see if there is a difference to be honest I am getting really disheartened by my failures!

If whistle is stronger than H3, is it possible or beneficial to use by coating onto rice crispies or some other carrier? if so how? what binder? I wont even bother asking if it will be too strong for a 3" plastic shell. I'd settle for that then work backwards.

[pihop]

Flipin' heck! I like it. Well my 3" shells are no where near that good! I really had high hopes moving up to whistle booster from just plain BP. I was scared as hell making and handling a few grams of it. So either it must be rubbish what I have made or just no where near as strong as flash. I read all the hype about whistle and how it is called organic flash and second only to flash. H3 being next lowest on the passfire list. I wont be using chlorate so wont be making any H3 to try.

I might try whistle at 76/23 next to see if there is a difference to be honest I am getting really disheartened by my failures!

If whistle is stronger than H3, is it possible or beneficial to use by coating onto rice crispies or some other carrier? if so how? what binder? I wont even bother asking if it will be too strong for a 3" plastic shell. I'd settle for that then work backwards.

To me it sounds like your a bit to cautious with flash and whistle mix. Not that one shouldn't handle the mixes without great respect but beeing afraid of two very useful comps. will really hinder (is that the right word?) your work.
I too was overly cautious with these comps when I started using them but then I actually tested howsensitive they were to shock and friction.
My advice to you is to try and ignite a tiny amount of whistle mix and flash by friction (IE mortar and pestel) and by shock (small hammer) just to see how sensitive your powders really are.
Ofcourse one should wear face protection that covers your whole face, heavy leather gloves, ear protection and non flammable clothing while performing these tests.

My experience is that botch comps are rather hard to ignite with friction, if you grind a tiny bit of flash in a mortar you will have to press down pretty hard to get it to pop.
When hitting it with a small hammer I had to hit the small pile several times but when it ignited it produced a bang almost as strong as a firecrackerwith 1 gram flash would (i used about 0,1g).

I must point out that I still use great caution when handling or mixing flash or whistle mix, I never mix with tools I only pour it around on two pieces of paper (whats the process called again?) to avoid all sources of friction.

Edited by pihop, 12 September 2007 - 03:43 PM.

[maxman]

I made a small batch of whistle 76/23/1 red iron oxide (the wet way ) as previously mentioned. It's nice and dry now so I filmed a 1 gram pile. I think if anything it is slightly slower than 70/30/1 mix. (not much)

I've just put together a 3" plastic ball shell of 3/8" firefly stars, these are nice and hard and don't need a prime. For the break I have used 25g BP on crispies 5:1 and 17g of this new whistle mix! I'm fed up of my wimpy breaks. To be honest I still don't think this will cut it either! I think my whistle just aint fast enough and regardless of the amount I put in, the shell will just pop open. This is going to be my last test with whistle mix (at least for the time being) I suspect my sodium benzoate might be the cause so unless I can get my hands on some potassium benzoate then I give up. I suppose I could always succumb to flash but since I have no Al then that's not an option at the moment.

I usually fibreglass tape my shells by one turn around the joint and four strips vertically. Does anyone else use this method? or should I tape all around? as in passfires three strip method (not with paper with tape though)

[BrightStar]

I usually fibreglass tape my shells by one turn around the joint and four strips vertically. Does anyone else use this method? or should I tape all around? as in passfires three strip method (not with paper with tape though)

Hi maxman, with whistle boost in plastic shells you certainly do need some extra spiking - the more the better. Unlike flash that hammers the shell open, the whistle just helps to rapidly build up the pressure in the BP and needs to be well confined.

Looking at some plastic shells I have recovered after use with BP + whistle, they tend to tear around the weak seam - not the joint itself, but usually just next to it. If the BP alone is sufficient to do this before the pressure builds up, the whistle may not have much effect at all, so extra spiking is helpful.

When I used fibreglass tape on 3" plastic ball shells in the past I have tended to use lots of it - up to 3 complete layers. Each layer is wrapped as a continuous length in a kind of 'offfset orbit' pattern around the poles - changing orientation between layers for even coverage. This gives a very symmetrical, medium sized break.

I'm just finishing a 3" plastic ball with whistle + BP now with a new hybrid method - I wrapped it with a layer of masking tape, then pasted with 4 layers of Kraft. This looks much nicer than the tape. I'll let you know how it goes... I really don't like using flash if I can possibly avoid it

Edited by BrightStar, 14 September 2007 - 07:31 PM.

[maxman]

SUCESS! At long last. As per the shell I referred to above I decidied to fiberglass tape this one twice round the seam one single vertical strips ALL round the shell. Unfortunatley the shell veered off a bit and deployed its payload directly overhead! (I wont be that close again) The break was HUGE! the bang echoed like crazy. I wonder now if it was too big, I'm not complaing though. Not sure all the stars lit as they were not primed. The break was so big my girlfriend ended up filming a blank space. Here is the video of what was filmed. Watch this space.

[W.P]

I recently aquired some plaster board tape which is basically a mesh with an adhesive layer. Is it possible that this tape could replace string for spiking shells? Here are the pics:





(There is no cellotape involved, it's literally a sticky mesh)

And could someone tell me whether this is just fibreglass tape? Thanks.

[Jerronimo]

That looks like fibreglass to me, can you break it easy or is it realy strong?
The fibreglass tape you mean is called filament tape.

[paul]

W.P: I know that stuff and tried using it before as well. The problem is the not very sticky glue.
You may try to put it around your shells (preferably canisters) but be sure to "soak" it with
some good glue like PVA. It won´t work as literally ONE layer if you don´t reinforce it.

Edited by paul, 16 September 2007 - 06:34 PM.

[maxman]

Use cricket bat repair tape from JJB

[SwissTony]

JJB online is out of it at the moment.
If there is a big requirement for this, I maybe able to get my dad to get rolls cheaper from work (Newbery Cricket)

[BrightStar]

Here's a quick 3" test shell to use up some rough cut Win20 stars I had lying around... It's a plastic shell with a 2g 'whistle bag' tied off to a silver flying fish time fuse and about 25g of BP on grass seed burst with a few green fish. The plastic was pasted with 4 layers of kraft in place of my normal fibreglass tape.





Here's the vid (1,162KB divx avi): 3" Win20 glitter shell

A few conclusions on this construction method:
- The finished shell OD is smaller than with tape spiking and was a loose fit in the standard mortar. I used 1/10 weight of lift rather than my normal 1/12 but it was still a bit weak.
- Silver flying fish isn't that impressive as a time fuse - in the sky it just looks like a white dot. Probably better to stick with tried and tested visco and add a comet in future.
- 2g of whistle with 4 layers of kraft on plastic gives a good bang to the burst, but I couldn't really judge it with these uneven stars. I can't see much advantage in using the central bag over just mixing it in.
- Win20 gold glitter is very bright has a really long hang time These stars were only 6mm thick but burnt for 5.5 seconds - actually too long for this use. I'd originally made them as a glitter pistil for a larger shell for which they would be ideal.

Anyway, onwards and upwards

Edited by BrightStar, 19 September 2007 - 12:13 PM.

[maxman]

Very nice shell brightstar! I think the break looked as big as mine in This link.
I think 17g whistle was a bit to much in my last test so gonna back down to 12g and see what happens.
Brightstar I think you do well to lift a 3" shell with what? about 15g? BP I use 28g as that is what was recommended on passfire. I used less once and it was very low.

[BrightStar]

Brightstar I think you do well to lift a 3" shell with what? about 15g? BP I use 28g as that is what was recommended on passfire. I used less once and it was very low.

Thanks maxman. The burst you got on the latest shell was great - good enough for a 'spider web' salvo. Glad you got there in the end

I only had 12.5g lift in this one. In the past I used my own cardboard mortars (about 18" long inside) which were nice and quiet but have now upgraded to standard fibreglass tubes (about 15" long inside). I might have to increase my lift accordingly, but it does diminish the effect if a 3" is lifted too high.

By the way, as a tip for the forum, if you find a satellite photo of your shell testing site on Google Maps and click 'My Maps' there is a distance measuring tool you can use to check safety clearances. At this site I have 350m to the nearest country lane, 650m to the nearest farm building and about 30m to BrightStar in his PPE. Assuming a minimum of 70ft (21m) per inch of shell, this should be fine for small tests.

Edited by BrightStar, 19 September 2007 - 01:54 PM.

[cooperman435]

From experience of my 3" gamon plastic shells using flash and whistle as a booster I can offer some help:

Whistle has to be confined just like BP but reacts much more violently when it is. An easily ruptured shell case will not gain much if anything at all from whistle no matter what quantity.

I find using flash makes it easier to ensure an even burst when wanting both powerfull large bursts and smaller drooping bursts as it doesnt propell the stars itself. Also because of the speed and heat of combustion even unconfined it massively speeds up the rate of ignition for the bp filler/burst charge so burst size can quite easily and accuratly be dialled in.

The seal on the plastic shell is the most importaint detail. Wraping a plastic shell well will nearly make up for poor sealing of the two hemis but especially when using whistle the pressure inside the shell before it ruptures has an expinential effect on burst size and strength.

When using flash the seal is not quite as importaint as the pressure is built up so fast and violently by the initial flash burst that the shell case is up to pressure well before it has chance to burst.

try granulating or putting your whistle onto carriers to aid flame propagation further.

[sasman]

Just fired this one..8" Plastic Ball shell ..Made a few mistakes in construction.. but it worked ok..Because it was large i tried to make some better glue for the shell.. i used methylene chloride + a few shell pieces dissolved in it to make it thicker..

But i found that it is no were near as good ..the joint bubbled up and was all soft..not very good!!... Also made a new clamp for holding the shell halves together ..and i tightened it up to much.. and the shell was slightly deformed.. ..I just cant seem to get the knack of glueing the hemis together 100%...Hopefully i will do better next time..

I had to guess how much lift to use 150g seemed about right for 4.5 second delay .. I placed the mortar at the bottom of a small hill and the camera was 30 or 40 foot higher it was at least 150 yds away .. It was pretty windy and the shell blew nearly overhead of the camera..But if you look at the 2nd clip which is filmed well over a mile away .. you can see the effect much better..

Edited by sasman, 25 October 2010 - 09:30 PM.