The big bumpy stars topic

[GraafVaag]

Hi there,

 

I've been rolling stars for about a year now, with differing results. I'm using a stainless steel starmill, rotating at 40-80rpm..

 

Now when rolling a glitter composition, a colour composition or an other non-milled mix, everything's all right. All the stars grow with the same speed and they're perfectly round.

Example from a 100g white strobe batch: Batch of stars - One star cut in half.

 

Now when rolling a chrysanthemum composition the stars grow bumpy and ugly! This is because the mix is so fine and/or in flake form.. (4h ballmilled) Before I continue, two pics from a batch ugly stars: (containing Ti by the way)

Just started rolling... And by the time I gave up.

 

After telling him the problem Freakydutchman told me to 'rice' the mix. I should process it with 10-15% water, and dry overnight. Done so, I made a full batch of hard lumps; not what I was looking for. Tried to 'press' this through the 60# sieve, well, don't even mention it. The lumps were way too hard. Next thing I tried was milling these lumps for about 20 minutes, now I ended up with 50% very fine powder, and 50% big lumps.

Well, to make a long story short, ricing the mix didn't work out as it should do.

 

Someone else told me to let the sprayed water 'work in' for a while before adding the mixture. So, I sprayed water over my stars, let them roll for a minute and then I added the fine chrysanthemum mix. Unfortunately, after I added 50g this way I again ended up with bumpy stars.

 

Yet another person told me to use 50/50 water/alcohol. No story here, just didn't work.

 

Today I started rolling a batch fuchs pop glitter containing 63% slow meal. Guess what? Bumpy stars.

 

I'm out of ideas, how can I get nice round stars when using a long milled mixture? Everyone should know this problem! Why do I seem to be the only person unable to solve it?

 

Share your secrets!

GraafVaag

Edited November 18, 2008 by GraafVaag

[Chris]

What kind of quantities are you rolling? Comps with high charcoal content are tough to roll if you start out with very few cores. Also, if your cores are very light, it might prove difficult to get them start rolling. Generally, using more cores helps. When you sprinkle composition on the rolling stars, instead sprinkling it around directly from a spoon, apply the comp on the stars through a 60 mesh screen. You will get a very even distribution, which helps preventing lumps which will eventually spike your stars. Also, do not belittle the effect of alcohol when rolling Charcoal comps. It will reduce surface tension and hence roll smoother and more dense stars. If you did not notice any improvement, it is because other factors contributed more to the deformation.

[GraafVaag]

I mostly roll 250 up to 400 stars at a time. The cores used in the third/fourth picture I posted weighed almost 1g each, the aim was an effect change. I tried adding the mix through a sieve, still bumpy though. Edited November 18, 2008 by GraafVaag

[FREAKYDUTCHMEN]

Rice with 50/50 water alc, so the dextrin can't really bind the comp. I think 10% will do. Even willow mix rolls nicely.

[Miech]

Or do it the easy way, and rice it without dextrin. Then add the dextrin to the solvent in your spray bottle. The exact amount of dextrin isn't very critical, so if it is somewhat more or less than mentioned in the composition it shouldn't be a problem.

 

I found wetting the stars so much they almost stick together works good for some compositions, it may be worth a try with chrysanthemum.

[Bonny]

IIRC, in Bleser's book 'Round Stars and Shells' For heavy charcoal content stars I believe he mentions ricing the comp, drying and then ball milling for a short time to bring the material to around 100mesh, which should be ideal for rolling. I'll check later when I get home.

[tentacles]

If the stars burn okay, and the timing is still good, I don't see any reason why the bumpy stars should be of any concern, other than aesthetic. You might try a different binder, or 75/25 water/ethanol. With 50/50 and dextrin, you'll run into problems with too much alcohol content. ONLY use 100% water with SGRS.

 

How thick are the layers you're trying to roll? With charcoal heavy formulas, you need to roll in steps to prevent spiking/berrying. Slow Gold is a formula that's known for rolling lumpy berry shapes, but it takes light beautifully this way, so I don't worry about it.

[psyco_1322]

Bumping stars are ugly, but they burn just fine, the only problems are exact timing and the fact that if the bumps get too big they quite growing. I seemed to be skilled at making a nice batch of stars, turning around to make another just like it and getting spikes. 50/50 wetting agent works wonders, though you still have to limit how much comp you add to the stars. Charcoal streamers roll way different than colored comps, colored stars will eat as much comp as you can feed them, while charcoal stars just throw it back up. You need to add in way smaller increments than with colored comps. Why not trying to roll your charcoal comp with out milling? Or knock down your milling times.

[Mumbles]

Another thing I've heard of is after you're done is to let them roll themselves out. 15 - 20 minutes, maybe even a half hour. As they begin to dry add more water. I've heard that they eventually pound themselves out if you have appropriate cascading action. It also results in more dense stars.

 

You may also want to look into the Toro method. Very dense, very round, very smooth stars.

[Yankie]

Rather than ricing the comp and getting hard to break lumps, why not granulate it then mill it for a bit?

[FREAKYDUTCHMEN]

Normally you wouldn't get hard lumps, so it's less work instead of granulate and mill it.

[50AE]

If you let them roll themselves without adding anything, like Mumbles said, wouldn't they start to smooth their surface from the friction, making them more round ?

[FREAKYDUTCHMEN]

When letting the stars roll a period of time, sometimes the stars will schrink and the composition will stick on the starrollers inner surface.

It's worth to tray again.

[Speed]

My chrys stars look the same. Doesn't seem to diminish the effect and the stars seem to lock together when loading round shells making it a bit easier to build.

[GraafVaag]

Hi there,

 

Thanks for al the reactions! I tried ricing a maxture again, but now I first made the mixture into pulverone the regular way. This was dried for a few hours, and then I rubbed it through a 60 mesh screen.

 

Well, actually I dumped it on my 60# screen with one kg of lead media, and then I 'sieved' this untill all the passing 60# 'pulver' was lying on my sheet of paper.

 

I have yet to roll this composition but it looks very promising.

Edited November 25, 2008 by GraafVaag

[Miech]

To give this topic a little bump, I rolled perfectly round TT stars yesterday. I first ball milled the composition without dextrin until it was airfloat. Then I riced the batch, using (I guess) 15% water. Because of the absence of dextrin there is no need to pulverize or mill it after ricing. Then I dissolved 5 grams of dextrin in hot water, and added that to 25 grams of TT composition. I added alcohol to this slurry until it became almost liquid, to prevent the dextrin from sticking too much and to speed up drying. Then I rolled the stars using the toro method.

 

It takes some practice to find the exact amount of slurry you should add at the beginning, but when the stars grow bigger than approximately 8 mm you can just pour in some without measuring the amount too much. The key to round stars seems to be to use just enough slurry to give the stars a satin shine. The slurry will fill up holes and caves in the stars, making them smooth and round.

 

I started with round cores however, when starting with cubic stars or very light cores you probably need very thin toro to prevent the cores from stiching together.

[GraafVaag]

Nice work Miech, now I've got one question for you. What was the avarage mass of the cores? When I start with blank cores that is about 0.045g each*, however rolled cores for a change-effect weigh about 0.4 to 0.6g each.

 

*) I use this number to calculate how much cores to add. 18g of blank cores means +- 400 stars.

[Miech]

Measuring the weight of 100 cores gave me an average weight of 0,104 grams per core. I use matte finished glass pearls I bought at 'Blokker'. Because they aren't shiny the first layer of composition sticks very well to the cores.

 

Something in Dutch to clarify where I got my star cores:

Matte glasparels dus. Ik heb de mijne gekocht bij de Blokker voor iets van 2 euro, ze staan in de buurt van troep die je in vazen stopt ter decoratie. De eerste laag compositie plakt veel beter aan de matte glasparels dan aan de glimmende, dus ik zou je vooral de matte aanraden.

Edited December 1, 2008 by Miech

[Karlos]

Really moist stars(torro, much of liquid)) in the roller = prevent from the formation bumpyness stars.

[Miech]

Yea, I drew that conclusion. You will need to use a lot of alcohol in your liquid to prevent the stars from sticking together. After a while you see in a glance if there are stars sticking together, even when they are moving through te bowl. Twins and Chernobyl-ish star lumps are more shiny where they stick together than the other stars.

[GraafVaag]

Yep, I really switched to toro-rolling now! I use alcohol for the toro, with red gum as the binder. The funny thing is that my star roller even looks cleaner after toro rolling than after spray-rolling. The moisture only gets to the stars, nothing is left on the bowl.

 

Ricing still didn't work for me, toro does.

 

 

EDIT: A picture of one batch of TT to blue stars:

http://i236.photobucket.com/albums/ff7/graafvaag/Fotos-0891.jpg

Edited December 25, 2008 by GraafVaag

[swervedriver]

Yep, I really switched to toro-rolling now! I use alcohol for the toro, with red gum as the binder. The funny thing is that my star roller even looks cleaner after toro rolling than after spray-rolling. The moisture only gets to the stars, nothing is left on the bowl.

 

Ricing still didn't work for me, toro does.

 

I found the same thing, I used red gum bound comp torros to prime stars in my roller and that barrel was really clean, nothing stuck. when I spray, I get all kinds of stickage going on. Are you using torro right from the start, on the cores? In my case, I was putting the torro, then dry comp on already dry stars.

[Miech]

It is always recommended to allow stars to drie before applying another composition to it. This is especially of importance when the compositions are using a different binder, or when one of the compositions is charcoal heavy or dries in a non permeable layer. Drying stars between switching composition speeds up the overall production time and prevents 'driving in' of moisture.

 

I start with toro straight from the cores. It's a little bit of PITA at the very beginning, but once they are rolling and have grown somewhat bigger it is really easy. I have had no luck so far with rolling red gum bound stars. Either the toro doesn't stay homogenous (even with stirring) or the stuff sticks way to much. I think I should get an other brand of EtOH.

[FREAKYDUTCHMEN]

You don't need toro to prevent bumby stars, just spray a lot more then normal (like perc/rg/parlon stars, for example) You'll see your stars getting more round and the wall will be cleaner.

[FREAKYDUTCHMEN]

Graafvaag, how long did it take to dry those stars, and what kind of alcohol did you use?

I've got to prime some 18mm stars before the 31st.