Need a good red stars to roll or pump
Posted 12 February 2013 - 12:07 AM
Posted 12 February 2013 - 01:26 AM
SrCO3 red, a beautiful color!
Posted 12 February 2013 - 03:41 AM
Posted 13 February 2013 - 06:15 AM
I get the idea behind the Veline system, to try to get a full spectrum where brightness, burn speed, and range of chemicals used is limited to make them as similar as possible, and that having all the formulas in a set, mixable without worry suits many people.
However I would have done it rather differently, though not in a major way. The chemicals used in the Veline system are by and large the same as used in most coloured formulas. I'm having trouble thinking of any two coloured mixes using Potassium perchlorate, Barium nitrate or Strontium nitrate as the oxidisers that it is unsafe to blend.
The first thing I would modify is the MgAl content. While this metal is one of the most expensive components of coloured mixes for some people, going from 30% in the Rubber red to 7% in the Veline mix is going to be quite a step down. Like Barium, Strontium prefers to be quite hot to emit colour well. Less magnalium does not necessarily mean it's more saturated like it often is with blue, and to an extent you get more saturated and more bright with more MgAl... so long as you give it enough distance not to be blinded.
Buell red is considerably less than the rather extraordinary 30% MgAl of the Rubber mix, and is I guess a good compromise between the other two compositions discussed. However if you do prefer the brilliance of nearly one third Magnalium, there is no reason you cannot add 4% Dextrin to the mix and bind with that. Adding some extra Potassium perchlorate, perhaps 10%, would offset the addition without altering the colour much, however I suspect that if you omit the extra KP it won't matter a lot. That composition is already completely over fulled, which you can get away with in extremely high metal mixes without it burning dirtily, so making a bit more over fueled is unlikely to push it past any tipping point.
Back to my off topic about modification of the Veline system. The blue should have no more than 3% MgAl, if any at all. The green mix is fitting with the realities that you need higher MgAl to get a good green with Potassium perchlorate/Barium nitrate/Barium carbonate, though I think it should be higher still, and since the primary focus of the system i simplicity, I say get rid of the Barium carbonate or the nitrate. What's with both? Perhaps to get the burn speed down to offset the higher MgAl, I guess, but at that temperature the carbonate won't emit green well,. Ideally you'll have no carbonate, less perchlorate, more nitrate and more MgAl. If you chose to use Carbonate for the Green, then higher MgAl is essential to get decent colour out of it. Buell red with the Sr replaced with Ba works, though I'm sure that any less MgAl and Carbonate and it would suffer.
The brightness of the blue will not match the other colours star to star, but this is a fact of life with copper as an emitter, and fighting it has consequences. Veline Blue does well for a blue formula with 6% MgAl, it is more washed out than most popular blue formulas using comparable chemicals. Another system for overcoming the different chemical requirements for blue and the corresponding lower luminosity, is to just double the blue star count. It may not work with every shell plan, but it is often an effective trick.
Edited by Seymour, 13 February 2013 - 06:23 AM.
Posted 13 February 2013 - 01:08 PM
@seymour, I like the idea of tuning the blue with less mg/al, i will try 3% and none. Will the mg/al content have as much difference if using cuo? I knew that last few grams had a use
Posted 13 February 2013 - 02:08 PM
I'm not sure if simply removing the MgAl from the formula will have best results. I guess my criticism of the compositions was highlighting where they do not match the conditions that I see as optimal for producing the colours they are trying to. However they are still tweaked to burn cleanly at those MgAl percentages. If you were to modify them in the manner I described you'd then need to re tweak them to get a polished formula.
Fortunately there are lots of formulas that match what I was saying, that are already tweaked to burn well with MgAl levels close to what I think they should have.
In short, I suggest abandoning Veline, and adopting other similar formulas. Take Conkling blue, Emerald green and Buell Red. You can swap Strontium for Calcium in the red to make orange, just like Velines stars. They use the same chemicals as Veline, I guess they're not cheaper, but the difference in price is not large.
I can't see how the Veline system is really more versatile, though I admit that the having the ratios for mixing them to produce a wide range of colours figured out for you and published is a very attractive feature.
Edited by Seymour, 13 February 2013 - 02:10 PM.
Posted 13 February 2013 - 05:56 PM
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