starlight Posted April 2, 2009 Posted April 2, 2009 These days I have done some color using KClO4 oxidant and KClO3 and NO3 but 'I had a problems when they are stars assciugate.le had cracks on them, I used as a binder gum arabic, and' the first I face this problems. what may 'have happened?
Ventsi Posted April 2, 2009 Posted April 2, 2009 (edited) How did you dry them? If you simply let them dry in a cool dark place they should not have any cracks,no matter what the binder is. Edited April 2, 2009 by Ventsi
firetech Posted April 2, 2009 Posted April 2, 2009 cracks are usually caused when the solvent is released from the comp too quickly..and also usually means airbubbles-another thing you don't want
swervedriver Posted April 3, 2009 Posted April 3, 2009 I've had that happen using water/alcohol for binding comps containing both redgum and dextrin. The stars were dried indoors. I rolled the same stars with straight alcohol, dried the same way, and the problem went away.
starlight Posted April 3, 2009 Author Posted April 3, 2009 the stars were put to dry in a ventilated internal very
Mumbles Posted April 4, 2009 Posted April 4, 2009 First off, completely wrong section. This doesn't even have anything to do with compositions in general, or for a specific effect (which are also in the wrong section). I would let the stars dry for a day or so in an area where they are not being force dried. Let them sit on a screen for a day or so before putting them in a drying box. Not doing so will cause the exterior to dry faster than the interior and may cause cracking and weak stars. You don't mention any specific compositions, but you may want to include a few parts dextrin into your stars to get some mechanical stability while drying. Gum Arabic doesn't give a great deal of hold until it is somewhat dried.
pyrogeorge Posted April 4, 2009 Posted April 4, 2009 8mm round stars is good for emerald green composition?or i must make bigger diameter?i will use it in 3" and 4" shells
starlight Posted April 4, 2009 Author Posted April 4, 2009 composition and 'green organic Shimizu KClO4 BaNO3 parlor scialacca dex dex and the 'was replaced with gum arabic
Mumbles Posted April 4, 2009 Posted April 4, 2009 Ohhh, you added it dry? That could be the problem. It's designed to be made into a solution and used that way. If you ad it dry, it may not fully activate and give you soft stars, or may swell upon activation and give the characteristic cracks you're talking about, especially if you use a 1:1 equivalent of gum arabic to dextrin.
starlight Posted April 4, 2009 Author Posted April 4, 2009 it's relationship with rubber and dex 'was 1:1, and the rubber' added dry
Mumbles Posted April 4, 2009 Posted April 4, 2009 Where did rubber come into the conversation? Now, I am somewhat confused. I'd assume it's some sort of translation error.
Seymour Posted April 4, 2009 Posted April 4, 2009 (edited) I think he means Parlon I always add my GA dry, and my stars dry up flawlessly. I'd guess that they are being dried too fast. Starlight, is your drying location very warm? If so, I suggest putting them in a cool, dark place to dry slowly. Additionally, I think you will not be impressed with that star formula. You might want to try a new one. EDIT: Or it could be the cores swelling. What are you using for cores? Edited April 4, 2009 by Seymour
Yankie Posted April 5, 2009 Posted April 5, 2009 EDIT: Or it could be the cores swelling. What are you using for cores? I had that problem with using semolina (I think) rolled perfect stars, then the cores swelled and cracked them all!
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