rolling stars

[Maximus]

Hello all! I'm brand new to the forum and this is my first post. I've made some 3" shells with glitter and other charoal comps with some success. I want to start to roll stepped or changing stars so it seemed this recent thread would be an appropriate spot to gain some knowledge since I can't post my own topic yet.

 

Anywho, on the topic of rolling stars, I've been wondering if you have to prime a core before rolling on say a C8 or TT comp? Does something harder to light like Ruby Red require a hot prime layer before the outter charcoal based layer?

 

Not trying to hijack this thread but wasn't sure where to go with this. Thanks!

[dan999ification]

Hello all! I'm brand new to the forum and this is my first post. I've made some 3" shells with glitter and other charoal comps with some success. I want to start to roll stepped or changing stars so it seemed this recent thread would be an appropriate spot to gain some knowledge since I can't post my own topic yet.

 

Anywho, on the topic of rolling stars, I've been wondering if you have to prime a core before rolling on say a C8 or TT comp? Does something harder to light like Ruby Red require a hot prime layer before the outter charcoal based layer?

 

Not trying to hijack this thread but wasn't sure where to go with this. Thanks!

i use pinball prime over de cores and coloured cores i dont think charcoal comps will light most colours.

http://youtu.be/tgo03QPTCVs

 

dan.

[AirCowPeacock]

I beleive it is much easier to light a core because the star is no longer traveling very fast. I have heard this elsewhere on the forum.

[Maximus]

name='dan999ification' timestamp='1352296133' post='103681']

i use pinball prime over de cores and coloured cores i dont think charcoal comps will light most colours.

http://youtu.be/tgo03QPTCVs

 

dan.[/u]

 

Thanks to both of you for your input. Pyrotechnician, that was a really nice looking shell; the exact type of thing I aspire to do. Would you be willing to go into more detail about your priming stages when making stars like you've shown in the video? I've scoured this forum and the net for this info and am gitty now that I have the attention of someone that can do what I want to do.

I've read that some people will prime with a slurry and then add dry. Some will just add dry prime comp to the wet stars while rolling. Some let dry completely between stages. Oh my god there's so much to know! What's your take on all of this?

Edited November 7, 2012 by Maximus

[Seymour]

It does make it much easier to light the core now that the star is slower, but it still depends on the mixes. I would never rely on a charcoal streamer to light anything like ruby red or emerald green, though I have had success with KClO4 blue and purple stars.

 

While you may be able to get away without it with some mixes, I strongly suggest adding a thin layer of hot prime to light the coloured core.

 

At work I USUALLY roll the 'standard' sprinkle and spray method the whole way, including priming.

 

For my hobby on the other hand, I find it much easier to slurrey prime them. The consistency is very important, and unfortunately I cannot give you any data for what moisture content, because it varies hugely depending on the composition, and star size.

 

Essentially, you want it as thick as possible while still fluid enough to fully coat/paint the stars. This will be thicker as stars get larger. As with many processes, be very careful not to add too much! (slurrey to the stars). You add too much and your stars won't be round any more after you have sorted them apart from the stickey mass they form. Add too little and you can always add more!

 

This is all done in a star roller, or a tub/bucket that is stirred by hand. Once the stars have an even coating of slurrey, as you noted, you add the dry mix, and the stars are further agitated.

 

For colour/effect changing stars, the most important factor for them to look good is consistency in sizing. I have pulled this off to an acceptable degree by simply rolling nearly perfectly so the stars remain close to the same in size, but let me tell you, it is so much easier with a sizing screen or two, or a dozen.

 

As for quantities of prime, while many people weigh out 10% or whatever (depends again on the prime, the star size and a host of other facors, I usually in hobby stars just roll it so that the surface of all the stars is completely coated and showing the colour of the prime, then add about half as much again. One full slurry coating seems to be a good amount too.

Edited November 8, 2012 by Seymour

[Maximus]

I meant to give props to Dan999ification on the shell in the video but called him Pyrotechnician . Still learning the ins and outs of the forum. "smelt the smoke", pyrotechnician, pyromaniac.....all tied into apparent experience level (number of posts?). Ah...I get it now. haha.

 

So Seymour do you add dextin to your prime and get it to stick with water? Or do you use something else like gum arabic solution or NC laquer? I'm sure this also depends on the method used to make the star right?

[dan999ification]

depends on the star yes, for the stars in the video i used pinball prime and 75/25 water alc to roll stars and prime, because i hand roll the prime was applied in powder form just as you would roll stars, cores were primed, blue was rolled on and primed they dried overnight ( partly ) then c6 was rolled over the top, easy really.

For charcoal stars bp primes are normally used with dextrin and bound with water as that activates the dextrin

for parlon or redgum as the binder acetone or alcohol are used as the solvent, there are of course many options.

 

Dan.

[Maximus]

You guys have been so helpful. I have to try this stuff out soon! Okay last question for a while.....

 

So as a general rule of thumb your prime will have some kind of a binder in it right? I'd guess since your solvent was water/alc., your pinball must have had dextrin in it. If you had a prime containing red gum or parlon w/o dextrin, you may use acetone or straight alcohol to get it to stick.

[AirCowPeacock]

Gum Arabic, SGRS, and Dextrin are common water soluble binders. Parlon is Ketone (Acetone, MEK, ect.) and non-polar (Toluene, Xylene, ect.) soluble, and Red Gum is Alcohol (Methanol, Ethanol, Isopropyl, ect) and Ketone soluble. Lower alcohols will not dissolve an appreciable amount of Parlon.

[Seymour]

Dextrin is the most common binder in prime, but largely because it's the most common binder overall. Usually the same binder is used for all layers of the star, and the prime, though many exceptions exist.

 

I used to use Gum Arabic mainly, though lately I've been using Dextrin a lot. I consider them interchangeable. I tend to use GA as a powder instead of the much talked about solution.

 

So, yes, prime almost always has a binder added to it, though, sometimes the dry part of the toro method, or even the last sprinkle of the sprinkle/spray method is added without the binder, and because this layer is so thin, and the star is able to let some binder migrate, it sticks just fine. However that's an extra step without any substantial benefit, so most people just use binder all the way. Often this is to add a final layer of very fast BP as a final final prime, and who can be bothered screening in dextrin when the 0.5mm layer will stick well anyway?

[dan999ification]

pinball prime uses red gum as binder, i use mainly veline colour stars the comp contains dextrin, redgum, and parlon, you could use water, alc or acetone to bind the stars.

Since i rolled these with water/ alc it made sense to use the same for the prime,

When i cut veline stars i use acetone to bind the stars and adhere the prime to them.

 

Dan.

[taiwanluthiers]

Do you need to use SGRS as a binder in order to use the toro method? I tried to toro dextrin bound stars and it ended up making a huge mess.

[Seymour]

I've used Dextrin and Gum Arabic mostly, and once Parlon/Red Gum co-binders (acetone based slurry). I've never used SGRS, so I may be handicapping myself, though in my experience once you get a bit of a feel for it, Toro is easy enough with all of those binders, though I'll admit using Parlon/RG was a good bit harder.

[AirCowPeacock]

10%-20% Parlon (in composition) and 2%-5% Red Gum (in solvent) with acetone produces the hardest stars I've ever felt. It think I would have to try hard to break them even with a hammer. Its my prefered way to bind. The few times I've rolled stars I used 10% Red Gum in composition with Alcohol though, I was concerned about acetone disolving my spray bottle and Red Gum clogging it up. Still made some hard stars.

[Shadowcat1969]

Well i got a chance to try out my home made star roller this evening and everything was going fine till my reostast started acting up wide open or nothing i think the weight changing had something to do with it, but i did get some .25" stars out of it, so back to the drawing board. I am going to try to find me a variable speed drill.

 

Mike, I know that when you look up Star Rollers on the internet you find a lot of them built with drills, and I did that myself, but I got to looking at it and the drill motor does a lot of sparking in the housing, and when rolling stars you end up with a fair amount of dust in the air. I think the two conditions don't mix too well.......personally I have retired that machine and am working on putting one together with the wiper motor from a car in a pull it yourself junk yard and a computer power supply.

 

Just something to think about.

[dynomike1]

Thanks Shadow i thought about that to. Are you sure that a wiper motor is fast and strong enough?

[graumann]

The most anemic wiper motor I've seen has been 30-50W, plenty to turn quite a few kg of drum and composition. From previous experience most seem to operate in the 20-60rpm range.

[Shadowcat1969]

I've seen a few on various threads here, and on other forums. I grabbed the motor when I was at the junk yard for other stuff, and I hooked it up to my car battery and it has PLENTY of torque to turn a good size bowl/bucket and stars. Think about how much your car wipers move when they push a load of snow out of the way, and that is only one wiper motor running BOTH wipers. So I'm pretty sure it'll do fine. It seems to turn about the same RPM as I was using with my variable speed drill too, so that should work out pretty good. If I want to change it I will pick up a couple of pulleys of different sizes and a belt.

[Maximus]

depends on the star yes, for the stars in the video i used pinball prime and 75/25 water alc to roll stars and prime, because i hand roll the prime was applied in powder form just as you would roll stars, cores were primed, blue was rolled on and primed they dried overnight ( partly ) then c6 was rolled over the top, easy really.

For charcoal stars bp primes are normally used with dextrin and bound with water as that activates the dextrin

for parlon or redgum as the binder acetone or alcohol are used as the solvent, there are of course many options.

 

Dan.

 

I've been pressing charcoal stars/streamers and recently screen cutting color comps. I started with the red featured as a project from Skylighter. Followed instructions to the letter and have had favorable results. Most recently, I've adapted the process to make some Yankies Purple and Pihko Blue #2.

 

Now with these screen cut stars which I've bound with Acetone, would I have a big problem using them as cores for a dextrin bound C6, C8, TT, etc? If I add dextrin to the pinball prime and roll with alc/H2O will the pinball act as kind of an intermediary between the parlon bound stars (which also contain red gum) and the dextrin bound charcoal comp?

 

Hope I'm not sounding stupid here......

[dan999ification]

you can wet the cores with acetone and then shake in the prime, repeat.

Wet with alc and shake, repeat, priming the pattie both sides and the stars straight after cutting works best for me.

No need to add dextrin to the prime just use a solvent suitable for the red gum it contains, although acetone bound parlon stars are resistant to water i wouldnt use it to prime acetone/alc bound comps.

They wont roll too easy being square, patience until they round off is needed, the colour will also turn on randomly while the streamer is still burning as the corners will light. Sizing as seymour says will negate this but you will need round cores.

What size are the cut stars? What are they for?

Dont worry it took me two years to get my head around all this before i made a single colour.

 

Dan.

[Maximus]

Thanks for chiming in again, Dan. Well so far I've screen cut with a 3 mesh screen. So they're probably ~8mm. I'm making 3" and 4" shells so from what I've read, I may need to cut them smaller if I plan on using them as cores.

 

Like you I prime just after cutting and I was pleased to see that with hand rolling, they became almost completely spherical after the recommended amount of prime was added. I think I'm on the right track but just need to make them smaller if they're to be cores....

 

So let's say I make them this way and they are small enough to be cores......Then let them dry and roll on some charcoal comp? If I am to avoid water to bind, it seems I must use another binder in the charcoal comp but red gum or parlon would certainly change the perfomance by adding chlorine or fuel properties right? I haven't seen a formula for a charcoal comp that wasn't bound with dextrin....

 

Oh yeah and I'm not overly concerned with perfect timing as far as the changing affect goes. I'll be thrilled if I can get it to work at all. then, set my sights on perfecting.

 

Max

[dan999ification]

i normally cut them between 2 and 4mm for 3 inch shells to give space for the streamer comp, it needs a good few mm to develop into a flower before the colour, my last failed that but like you say make it work then tweak it.

Once the cores are dry and primed i roll the streamer comp with water and dextrin, no need avoid water or change any comps, baring in mind that i use veline colours that have no real problem with water, the reason i dont use water to prime these stars is i prime while the stars are wet with solvent to get a good bond.

Im trying to perfect rolling from powder and spraying it with water/alc mix to produce the cores, with varying levels of success, in that case i would use water/alc for priming.

The good (and confusing ) thing about veline stars is how versatile they are the combinations of manafacture methods and effects you can get is endless and of course personal preference.

 

Dan.