42 replies to this topic

[Phoenix]

I won't say it definately wasn't that, but I don't think it was. This problem seems to affect 5mm stars that have been in a warm room for a week (and seemed dry for 6 days), but using 3% binder resulted in stars, even 15mm comets, working fine after drying for just a couple of days (or all week).

Possibly your stars were encouraged to break up by having a "core" to burn from where you poked them?

I had had one interesting idea that could make use of this. The over-bound star comp could be rolled on grain BP cores. This, in theory, would make a dim orange star that would then break up into a cloud of fire dust. Kind of like a crossette. I'll try this, possibly next weekend, and see if the cloud has a silver lining, or if it's just shiney nickel. (Unless I end up with a bowl of scum and glued up cores, as with most of my previous attempts at star rolling).

[dfk]

ya I've tried lampblack stars, these were my first attempts at willows.
To me they have a brighter, more lively but shorter effect than the charcoal willows

I shot a 4" lampblack willow ball shell using about 1/2 inch rolled stars(messy messy stuff)
It made a realy thick ball of sparks but NO willowing.
still testing but I added something like 10% AF charcoal straght to my lampblack comp sucessfuly slowing burn rate and adding more sparks

I have a batch of brilliant white to NEW lampblack stars that ended up at 3/4
to 1inch in diameter. I still need to shoot ashell of these, I will post details.

Note* I also have batches of blue to red, firefly to white, neon blue, and zinc spreader stars ready to be assembled into shells sitting in my shed(not good)

Ya i need to get on that, talk to you all later

Marcus

[dfk]

Thanks for the advice pheonix
I am going to try it out on my next day off..oh hey thats tomoro!
If what i hear is true, it sounds like all my problems might be solved

Marcus

[tajmiester]

Perhaps they build up a layer of hard dextrin on the exterior which prevents the interior drying well enough. Maybe if you used cut instead of rolled stars you could cut them in half again to product two, dry stars.

[Steve]

Charcoal stars can be very difficult to mix propperly by hand, even if it looks mixed it probably isn't. You really need to mill these star mixes to get a good effect. Also as Tajmiester said, some binders can dry on the surface to form a film, meaning it will take a month to fully dry the star, don't try to grow your stars too quickly if rolling them. And most ameatures don't know how much water is needed to make a binder work. You really need sod all, but you do, however need to mix it in for ages, I find kneading it in like d'ou workes the best the get it mixed well.

Steve

[BurlHorse]

Perhaps they build up a layer of hard dextrin on the exterior which prevents the interior drying well enough. Maybe if you used cut instead of rolled stars you could cut them in half again to product two, dry stars.

Sounds to me like this whole thread is about "Driven in" Stars. Yes Too Much Binder can cause a star to be driven in, I.E; Hard Exterior, Still wet inside. A bigger problem with Charcoal Stars of any type because the Charcoal holds water alot longer.

Shimizu used nearly exclusively SGRS for a binder, most of the "Modern" day hobbyist's use Dextrin. Which is a double whammy.

IMHO - Don't use anywhere near as much dextrin as called for in most formulas, 4% being my personal top for Charcoal Based Stars. Use SGRS if you have it, It is superior in every way as a binder for "Most" Stars.

When rolling, don't do it all at once, Build your cores up to no bigger than 3/8ths of an inch AND LET THEM DRY! This is the biggest mistake I made in the begining ( I was Rolling 7/8ths to 1" stars for 8" shells all in one shot!) Which of course looked great and but burned all the way to the ground and then some (Willow or Firefly)

Do not try to force them to dry, (I.E; Fan, Oven Etc, as you will only compound the problem of the surface of the star "Skinning" over and not being able to release the water the charcoal is holding. Lampblack is notoriously slow drying, so Roll or cut those a month in advance of when you think your gonna need them.

Regards, Stay Green,

Bear

[Phoenix]

Thanks to all who replied.

Like I said to Pyromaster2003, I don't _think_ they were driven in, as they seemed dry inside, were rock hard, and it seemed to affect even very small stars. However, many of the star batches suffering from this were force dried and all were high in dextrin, so the conditions would have been right to cause them to be DI, so I'll avoid force drying in future, and keeping to 4% or less of dextrin is my general rule anyway.

[sasman]

I'm just about to make some Tiget Tail Mix and have read 2 methods of mixing the comp
.1 . is to Ball Mill for a long Time Bill ofca mentions 20 Hours? David Blesser says 12hrs., then dampen the mix and granulate then ball mill the Granules to 100 to 200 mesh
.2. Use the CIA method lots of water to dissolve the KNO3 to saturate the pores of the Charcoal?..This method is used in Tom Perigrins Book IPP
I have been reading posts from various sources on the Net and im not sure which is the best? MortarTube mentions using 10% water But the formula i have read uses 20%?..I like the sound of Pheonixs method of dissolving the Nitrate in water to saturate the carbon particles.. Has any 1 tried both methods to see which works best?..

>I have got a batch in the ball mill total run time 18 hours and am about to reload and do another batch but not sure if i should use the CIA method instead..After that i got some willow Comp any Tricks way to make that?

[Richard H]

Not tried tiger tail myself, but I would try several methods to get an effect that is the most pleasing. I would try the ball mill method first, and then alter the milling time to change the characteristics of the sparks. 12 hours sounds about right to me.

[alany]

I'd use Chrysanthemum #6 myself, it is much more forgiving.

Tiger Tail being roughly half Charcoal is quite hard to dry out and has so little Sulfur it can be harder to ignite than other charcoal streamers. (Not saying it is hard to ignite, just relatively harder than C6 but perhaps not as bad as some lampblacks, being oxygen deficient it actually likes hard breaks but more sulfur helps IMO).

Because you have to mill the hell out of it, Tiger Tail can be harder to roll than somewhat rougher compositions. C6 needs to be milled well too, but you *can* get away with just screening it, dampening, grating through a fine sieve a few times then either rolling or pumping. Such a primitive technique produces a slower drossy star, but is still acceptable if you are lazy or ball mill challenged.

You can always use the same fine granulation trick to make fully milled charcoal and lampblack stars easier to roll too. I like it, I hate rolling 'talcum powder' compositions, they spike the stars and stick to the walls and make the process more dusty than it needs to be. I am really hopeless at rolling stars, so every little bit of luck on my side helps.

I like pumping slightly 'grainy' charcoal crossettes too, they are easier to get off the pump. They might even be easier to break, but I haven't had a lot of luck breaking them yet They aren't too crumbly either, if you get the moisture content right.

[Phoenix]

Yes, since I've started rolling stars I've found that when milled to dust, Tiger Tail tends to spike too easily. A solution I've tried is to mill most of the charcoal, with the other ingredients, but to leave some un-milled, and just passing 80 mesh, and mix that in afterwards. That makes it roll very easily, but I've been having a few sparks hit the ground from doing this, so I may just stick to cut stars and mill it all as I used to.

BTW: Igniting this star will not be an issue. I've never seen one go blind.

[sasman]

Thanks for the info guys.. I was tempted to make my next batch with the CIA method but ill ball mill it instead...i just bought an electric timer switch so that i can leave the ball mill running most of the day but then turn off automatically at night.

.I am using Pine charcoal to make the Tiger Tail and burnt a small pile,it burns fairly slowly with lots of orange sparks which dont spray outwards but float straight up in the air with the smoke. and leaves a lot of black unburnt charcoal residue but i expect that when its being blown out of a shell it will all be burnt up.

[Phoenix]

In my experience, a pile of loose Tiger Tail comp will barely burn, and certainly not look very inspiring. However, once it has been formed into a star, it will burn much faster and more fiercly.

[sasman]

Well Tonight i finally got round to test firing some Tiger Tail Stars` i made a week ago i rolled them up to about 7mm let them dry for a few days then rolled them up to about 15mm.. I rolled about 1000 stars

..I have not Primed them and im going to try whistle mix and then Flash on BP coated Rice Crispies (750 g BP on 150 g Crispies) to break the shells. I may use 6" shell but more likley use 4" because i dont think i have enough BP coated RiceCrispies to make 2 6" shells ..This is my first test with tigertail so dont know how it should perform? So here is a video clip of some stars i fired ..Tiger Tail 3 Clips How do they look? the test were done in very strong wind so that may have effected the Tail But i was hoping for a much longer tail...How do you create a longer tail? add larger mesh charcoal?

...The video doesnt pick up how Fine the sparks were..They were fired out of a 3/4" inner diameter cardboard tube using 1 teaspoon(5ml) of 4 to 10 mesh BP 2FG? and the stars were simply dropped in the tube...

[Mortartube]

Your tiger tail stars look good to me. Firing them in still conditions should make quite a difference to the viewing. Don't add coarser mesh charcoal as this will not improve the effect but diminish it. You can ball mill the ingredients to help make them as fine as possible. The charcoal should be airfloat. Try experimenting with mixes with percentages around the formula stated to fine tune it to your requirements. Also to make them burn longer make them as pill box stars, this will increase the burn time. I use an old felt tip pen barrel to roll the pillbox spools on and cut them to about 10mm long. Just dry roll them and tape them using newspaper or similar.