slow burn composition

[Arw]

Hi all.
I need a composition that burn too slow,about 30sec/inch.
I see that composition on a flasher.
Is anyone know about this?

[lloyd]

It's called "Glusatz" in Germany.

 

------------------------------------

Glusatz

 

Barium nitrate 75.5

AF Charcoal 10

Sulfur 10

Meal powder. XF 3

Cab-O-Sil 1

Carboxymethylcellulose 0.5

Water +6

 

Pre-dissolve CMC in water. Add dry ingredients and screen well to mix. Allow to temper wet

for about an hour, then screen-granulate through 20-mesh, and allow to dry.

 

OR…

 

Barium nitrate 75.5 (not 100 parts)

AF charcoal 10

Sulfur 10

Cab-O-Sil 1

Dextrin 5

Water +6

 

Dampen, screen, and allow to dry.

 

----

 

Use to end-prime effects for delayed lighting, or rammed hard in small tubes for 30s/in. spolettes.

 

In both cases, if pressed, press dry or with no more than 5% added moisture. If applied as a dipped surface prime, wet to the consistency of VERY heavy cream, and dip objects in the slurry. Allow to dry thoroughly.

 

Lloyd

[Arw]

thank you.
that was so helpful.
but the composition that i saw was silver.it seems has Al or Mg or both.

[lloyd]

I doubt it was both silver and burning 30s/in (nor even 10s/in).

 

There are competing mechanisms at work, there.

 

For instance, let me ask you this:

If it were burning at 30s/in, where would sufficient gas come from to propel silver sparks away from the flame front?

 

Lloyd

[Arw]

Not silver sparks.not even spark propel away.

that composition was silver.like Al powder.

[Pyromaster]

I use it. Actualy a slight variant of it. It is silvery when mixed. My variant has a little bit of magnalium and different binder. Edited November 13, 2022 by Pyromaster

[Inserttext12]

Is there any way to make the reaction even slower?

[Mumbles]

Realistically, things can only be slowed so much. At a certain point compositions stop burning reliably. In my mind that is the difference between burning and smoldering. Something that crosses that threshold into smoldering starts to have issues with reliable burn rate and with potentially extinguishing itself.

 

Another area to investigate is the types of slurries used for more traditionally made beraq in the types of shells made in malta. These are generally a BP slurry with a burn rate modifier to my knowledge. I don't know what your application or hope for these types of composition is, but it may provide a different avenue to think about. I believe the most traditional burn rate modifier is a large quantity of gum arabic, somewhere between probably 3 to 30%. In larger amounts it's a fairly competent burn retardant. Others have used things like barium or strontium carbonate to achieve this effect. Carbonates can be over done more easily and be so effective they render something incapable of sustaining combustion. The other I've seen is Red Gum, or presumably some other sort of resin type fuel like phenolic resin, shellac, etc. This does have the interesting property of being able to be used with alcohol instead of water. It will dry faster, but may also be more prone to shrinking.

[Richtee]

Only thing I ever seen that slow was like rope fuse. Maybe even slower. But it’s organic nitrated stuff, and if you are looking to add a scent, well, that prolly won’t work. But I dunno. Some apple sawdust would be pleasing to me tho