Hard to ignite DE

[Almostparadise]

I'm using

37.5 bismuth trioxide

37.5 black copper oxide

25.0 Magnalium 100-200 mesh

Bound w NC lacquer

I put my torch on them it takes a minute before it starts to Glow and then it gives an extra loud bang. A lot more than a crackle. The problem is I can't get them to light.  They take so long to heat up that any prime I use burns out well before they're ready. I made them in the past and they were much easier to light. I was making them for star cores.

[pyrojig]

That comp looks off to me. Also try finer mesh magnal . Course will take lots of heat to ignite. Step prime etc. 

nc laq needs to be pretty thick honey like. And comp well mixed , then screened or cut small 1/8” or smaller

[Zumber]

42 minutes ago, pyrojig said:

That comp looks off to me. Also try finer mesh magnal . Course will take lots of heat to ignite. Step prime etc. 

nc laq needs to be pretty thick honey like. And comp well mixed , then screened or cut small 1/8” or smaller

Agree with magnelium mesh size

200 works well for crackling stars and it should be 50:50

I disagree with NC consistency.

Thicker NC creates problem if crackling star is tested in shell and not in a fountain.

The consistency of NC should be like cooking edible oil.

Add more acetone in it if your NC is too thick.

Also try out commercial NC if you are using homemade.

Try out again with 200 mesh magnelium ( 50:50) and thin consistency of NC.

Post your response.

Edited June 21 by Zumber

[Almostparadise]

I don't have 200 mesh. I'll try to get more 200 mesh out of the stuff I have now. Otherwise I have 325 mesh. I made the NC from double base. It's like honey. I put these through a garlic press and primed them w Jopetes crackle prime. I'll post back w results ty!

[Zumber]

Star seems to big in a size.

NC should be of good quality and thinner consistency.

If you put unprimed stars in loose bp and ignite bp it should be ignited and perform on ground.

Unprimed star size should be 1 mm to 2 mm maximum.

[Almostparadise]

I know what the problem is. I was using magnesium and not mg/al. The containers are the same. I've had the magnesium for a long time and don't use it. I was moving things around the other day so it ended up right next to the mg/al. Foolish operator error that could have ended up a lot worse. So at least there's that. I should have gotten rid of it a long time ago.

Edited June 21 by Almostparadise
Punctuation

[Zumber]

Anyways prepare new batch and remember changes to make as stated in previous posts.

[pyrojig]

@zumber 

your advise is good. But I have seen to thin of nc not be enough to get combustion to the temp needed for the ‘glow’ ignition of the metal. Thinning with acetone is needed as mixing progresses ( I left that detail out) . I have in past had success, mixing magnesium and aluminum 50% each. They have to be a pretty intimate mixture to work and very fine like suggested above 200 to 325 mesh. Wouldn’t suggest doing it that way. The best results came from Magnal mixed with some very fine atomized aluminum to boost the effect which gave it louder bang. But don’t start with that formulation (with aluminum) for the first tests of that comp. 

[Zumber]

Binder affects star performance a lot. Too thick NC represents more cotton nitrate is dissolved in lacquer.

I have very good experience of this.

I have prepared crackling stars with thick consistency of NC and tested it in a fountain as unprimed crackling stars....it has performed damn well next day I primed same stars and tested it in a shell and most of stars failed producing loud sound plus ignition.

After that I made change In NC consistency and primed star with same prime and it worked danm well in a shell and fountain with very loud sound and ease of ignition too.

This time sound was loud even if shell exploded at high altitude than testing in fountain. So since that day I am preparing with same changes since 5 to 6 years without a problem.

 

[pyrojig]

Excellent, thanks for sharing your experience. So your alteration are thinner nc( shotgun powder , home made nc, or commercial grade nc?)

thin syrup consistency, and what comp did you have your best results from ?

[Zumber]

5 minutes ago, pyrojig said:

Excellent, thanks for sharing your experience. So your alteration are thinner nc( shotgun powder , home made nc, or commercial grade nc?)

thin syrup consistency, and what comp did you have your best results from ?

No I have commercial NC I use it everytime. It is sold as very thicker consistency exact ratio is not known.

I re-experimented with it because it was creating problems with stars.

I am using red lead based crackling stars with same ratio like standard black powder. 75/15/10 red lead/ magnelium /cupric oxide.

Usually 10 percent cotton nitrate is dissolved in 100 ml acetone but I dont know what percentage manufacturer has dissolved but it was pretty thick like honey.

I added more acetone to thin it bit more and made 1 mm to 2 mm granules using wire mesh screen.

 

[pyrojig]

I think commercial is 25% … don’t quote me , I have to check my bottle for %’s. 
red lead gives great effect and is reliable . Most folks are scared of lead , but it is a staple comp for D.E.’s . 

I have seen how these stain concrete and glass lol , it’s hard to remove these stains .