Burning speed vs. binder

[dangerousamateur]

I just read this article here, was just posted:

http://www.skylighte...P_GO_GETTER_ADV

 

Now look at theese rubber star formulas:

 

Strontium nitrate 53

MgAl -200 mesh 19

Parlon 17

Red gum 11

 

And it burns so fast you they even made ge-getters that actually work as rockets

 

 

Now some time ago you proposed me independence red as a wonderful slow burning composition:

 

Strontium nitrate 50

MgAl -200 mesh 18

Parlon 16

Red gum 10

Dextrin 5

 

This burns really slow, iused dextrine only, no acetone.

 

What makes that huge difference in burning speed? Is it really just the binder?

 

 

 

And then the priming issue. The go getters are supposed to light WITHOUT any prime! I find this astonishing.

Edited November 26, 2011 by dangerousamateur

[Seymour]

I just read this article here, was just posted:

http://www.skylighte...P_GO_GETTER_ADV

 

Now look at theese rubber star formulas:

 

Strontium nitrate 53

MgAl -200 mesh 19

Parlon 17

Red gum 11

 

And it burns so fast you they even made ge-getters that actually work as rockets

 

 

Now some time ago you proposed me independence red as a wonderful slow burning composition:

 

Strontium nitrate 50

MgAl -200 mesh 18

Parlon 16

Red gum 10

Dextrin 5

 

This burns really slow, iused dextrine only, no acetone.

 

What makes that huge difference in burning speed? Is it really just the binder?

 

 

 

And then the priming issue. The go getters are supposed to light WITHOUT any prime! I find this astonishing.

 

 

I suspect water. Was your Strontium nitrate anhydrous in the parlon bound mix? It certainly won't be after it's water bound.

[Algenco]

I don't think water has anything to do with it.

Ned was doing some testing of Go Getter formulas and dicover he could test single "GG" by attatching it to a bamboo skewer

 

if the Independence Red burns slow with dextrin it would have to be because of the dextrin, that's assuming the comp was completely dry .

 

I've rolled Idependence red bound with dextrin and they dried/burned just fine.

Hydoscopic problems with strontium nitrate are due to contaminated Strontium, I use Dupont and Japanese without problem

[Mumbles]

I'll admit I've never really made much of anything in regards to parlon stars. I've been aware of this phenomenon before though. I've kind of wondered if the fast evaporation rate of parlon gives it a higher tendency to form small air pockets or cracks or something. It may also just be related to density of the finished star.

[Algenco]

I'll admit I've never really made much of anything in regards to parlon stars. I've been aware of this phenomenon before though. I've kind of wondered if the fast evaporation rate of parlon gives it a higher tendency to form small air pockets or cracks or something. It may also just be related to density of the finished star.

 

 

that's very possible, if you look closely at cut Parlon stars they do look porous

[mlanglie]

And then the priming issue. The go getters are supposed to light WITHOUT any prime! I find this astonishing.

 

The reason the go getters don't need to be primed is that the black match burns slower than a burst charge would. More fire for longer time.

[dangerousamateur]

Sounds plausible. Especially if it's molded in at the end.

 

My parlon stars do look porous too. But i have to admit that i used to much acetone, the dough was pourable. I guess that if the mix is less wet, there wont be so much bubbles.

[marks265]

I've made Go Getters similar to this a few years ago. I remember my second trials of this at a Mason City PGI a few years ago. I pumped parlon stars onto a small spindle. After the pumped stars hardened I pasted them in and had a small piece of fast visco stuck into the core of each one. No tube or prime was used and they still acted as little rockets so to speak. I only tried a couple of formulas and a magenta from Joel Baechle worked the best. But there are many more comps to try compared to the two or three that I have tried at that time.

 

Mark