1569 replies to this topic

[karlfoxman]

2 Hour milled bp is rubbish to lift a shell will no confienment, the lift charges for these shells was housed inside a small shell. The 6" ones used a shell 3" id and about 3" long, they have two disks at each end. One on the outside and one on the inside. Then they a spiked very well with jute/linen twine. Then you add lots of paste to the spiking and let it dry. That shell with 150g rubbish, slow, awful bp is now turned into a very powderful lifting shell! It had ease in getting a 4kg shell out of the tube. Shook the ground and burried my 6" fiberglass mortar about 2 feet into clay. It was left with 4" poking out the soil!

The Maltese use steel tubes as mortars, old welding cylinders and stuff he he.

[Anders Greenman]

Just wondering, Karl, how thick is your 6" fiberglass mortar tube? I have a six inch myself, but it's made of cardboard and it is not as practical as fiberglass

[Richard H]

The 6" tubes only have a wall about 4mm thick. They are very strong, but unsure if they would survive the lift of a large Maltese style multibreak!

[Anders Greenman]

That's pretty impressive! Though it's strange if they can survive a 90kg multibreak.

[karlfoxman]

They can cope well with flowerpots but the huge force from large multibreaks will destroy them, I think they may copewith a 7kg Maltese shell but any bigger and it will destroy it.

[karlfoxman]

This thread been dead for a long time, so im going to ask for some Maltese shell ideas. Im looking for effects/colours for 6" shell.

For example - 2 break maltese shell to bottom shot.

Break 1 - Half purple half yellow with williams no antimony glitter pistil
Break 2 - Half yellow half purple with williams no antimony glitter pistil
Bottom shot

This is a little follow om from my talk, the best idea gets a video of the attempt.

Please no more than 2 breaks and limited to colour effects only, im planning on making 2 shells.

Edited by karlfoxman, 27 January 2007 - 07:12 PM.

[TCblastmaster]

Hi Karl,

Nice idea. How about colour changing stars - green to red with the suggested pistil for break 1.
Break 2 (going by your idea) the reverse colour change with a pistil of glitter with dragon egg cores, plus bottom shot.

Or a hard breaking break 1 of charcoal firedust with red core, perhaps blue pistil as not to bright, and colour change with veline formulae for break 2 with the glitter and dragon egg core pistil - long hang time and added effect.

The choice is obviously endless and everybody has an artistic preference.

All the best. can't wait to see the end result. For the winning suggestion, testing by proxy!!

all the best

TC

[karlfoxman]

Good choice, but the Maltese shells use pumped comets as the main break and I also use pumped for the pistil stars. So limited to single colours im afraid. When I get around to making round stars ill add colour change at some point.

The charcoal with blue center is nice idea though! Personal fave of mine!

[TCblastmaster]

Hi Karl,

Glad you like the combination, subtle but complimentary and beautiful. Sorry, I don't know much about these shells, more of a spherical person myself at the moment as home made mortar tubes may not handle the lifting of multibreak cylindrical shells! I guess your presentation at the AGM would have filled me in on the details. What effects do they normally use?

I'm not sure about colour changing comets but perhaps that is an option if compositions with similar characteristics (Veline's for example) were used. Any graduated primes would obviously present a problem

What ever you decide on I'm sure the end result will be pretty spectacular.

Regards

TC

[karlfoxman]

Tiger tail and blue go very well together as do the colours lilac and yellow. Im building one that is a half and half lalac and yellow, maybe with alternate lilac and yellow for the pistil so a sort of double half and half. I can make the solid star pattern ones too now with micro stars for the star.

As for lifting these shells when each break weighs over 2 kg then you have to think of the tube strength, I will get away with a 6-7kg shell I should think but more will destroy the tube I should think. I am going to find some seamless steel tubes sometime for larger multibreaks. The lift method adds huge pressure to the tube, when I fired a single break with bottom shot (3.5kg IIRC) it burried the tube into solid clay! Quite some power in 160g Rubbish quality BP. Im sure ill be doing another talk on them at somepoint.

Take a look at some of the Maltese club web sites LINKS then browse the pictures and see what I mean by the effects that can be done with them.

[sizzle]

Karl, How about:

Break 1: William's No-Anitmony glitter with embedded red Micro-stars and a Winokur 20 Pistil.
Break 2: Blue Crossette with Green pistil.

[pyrotrev]

Now then there's a question!!! Having not really thought about it I would perhaps go for a huge umbrella* of yellow glitter comets or better still crossettes with lilac pistil for the 1st (highest) break, the one of those "quadrant" patterned colour shells for the second. I know red & blue are kind of traditional for those, but a 3 colour red/green/blue might be even more fun!
Regarding mortars, I'll see if I can track down some of the extra strength GRP types - or why not lay up some extra layers around a normal one.?? maybe add in some carbon fibre mat as well? Should be possible to make something as strong as a steel, with lower debris risk (think of that bottom shot going prematurely
), and a lot lighter to carry .
* use a rope tail to keep the burst normal to the ground.

[karlfoxman]

Thats a good idea Trev, Ill have a look at our 6" tubes ans see what is the best way to do it. I know we can get hold of some old diving cylinders and maybe welding ones that have failed the pressure test. Yes they will be very heavy!

Good idea on the shell too, dont know how easy it would be to get the rope attached ill have to look into that. Normaly the first break is fired onn the way up and the second at apogee then bottom shot on the way down 2 secs after. The quadrant design is a great one and ill bear that in mind, so the comets are split into 3 colours and then the pistil is too. I have a lovely aquamarine star formula I use and have seen similar in shells with orange.

If you could find some GRP tubes I would be interested, might be better than fiberglass.

[barra69]

Do not put carbon fibre into anything that burns: it is far more dangerous than asbestos when allowed to burn. Its one of the main problems we encounter with aircraft fires and modern man made fibres.

[karlfoxman]

Thanks for the warning but it would be on the outside of the tube as the tube is Fiberglass, It would also only need to cover 2/3 of the tube and not all the way to the top.